New Scrap

Name: Meraflor N. Montajes Course: MAEA 2-1 Learning, Insights, and Contributions Actually, in making our empirical study entitled “School Environmental Activities and its Influence on Attitudes towards Students and Teachers” I helped-out in making chapter 1 up to 5. I used to research and edit the conceptual framework, review of related literature, presentation, analysis and interpretation of data and recommendation. Well, in conceptual framework, I gathered the ideas and concepts from the experts who wrote the dissertations, researches and thesis works. For the related literature I researched from the internet and studies similarly on the empirical study that we made. On the other hand, I used to assist in the data-gathered of our study in interpreting and analyzing the data while in the last chapter I was the one who made the recommendation based on our conclusion of the raised problems in school environmental activities and its influence on attitudes towards students and teachers. As I investigated the empirical, I’ve learned a lot. First, I knew how to deal with the other members by sharing our ideas and opinions every time we gathered as one in Graduate School Library. And we had some fun at the same time, too. We were enjoying actually, the time we spent so much in study-making though we could still feel the pressure. Second, I knew how to manage our time wisely especially all of us that are came from far places. We handled it by texting and calling time to time with our teammates just to finish our empirical study in the deadline. Third, I learned so much how to be patient, and understanding in every chapter we made. Because often times we tend to get wrong in computation, grammars and etc. of course, we should edit it time to time just to give the precise and comprehensive information to our adviser. Furthermore, the insights there, through this study we can able to broaden our knowledge as teachers and administrators to be in the future in terms of environmental activities. These activities actually serve as one of the solutions in solving the environmental issues. So, it gives awareness and inclusive information not only to the teachers, students but the entire people who are living in this community. For the students, it will help them in promoting environmental awareness too. It will serve as a guide in supporting the school environmental activities at present and in the future.

Learning Gained From the Seminars/Workshops As a student, I learned a lot from the seminars/workshops that we had last January 2009. It helped me to broaden my knowledge in every topic that I’ve heard from the different speakers. Actually, they gave me an intensive discussion and comprehensive information in developing more our professional growth development not only as a teacher but an administrator to be in the future. In the first two seminars held at Bukidnon State University Gymnasium, the topics given by the different brilliant speakers were merely focusing on professional education. As teacher, it served me as a guide in developing our professionalisms considering of course the code of ethics in education. The educators are said to be the models of the youth however, today we should not only consider our tasks and responsibilities at home, in school but also in community. The speakers emphasized the extension of duties of teachers in community and the entire society. The lectures actually helped me to mold as teacher and leader to be in the future. It helped the teachers and instructors to strengthen their capabilities and skills for the transformation and betterment of the students, co-teachers and other people in terms of education. Well, they also emphasized the major principles in teaching that since the educational environment not only confined with the classroom but in the community as well, so today teachers should deliver already comprehensive or in depth discussions to the students with the use of modern learning. This modern learning has something to do with technology. Teachers should be technological-friendly in order to build up the innovative learning in school and community. They should be up-dated and creative in giving school activities and definitely still be guided accordingly with the values of education. Teachers should also teach the learners professionally and ethically in order to attain quality education. In short, values should be integrated and should be

shared accordingly and most especially in technological aspect in this generation. Of course, by considering those factors we can have a skillful, well-productive and transformative students, graduates, teachers and better citizens in our society. Furthermore, in the last seminar held at Kibawe tourism hall in Kibawe, Bukidnon, the speakers elaborated more on the teaching strategies and test construction. Teachers also should be well-informed in constructing test. They should follow the correct format in order to have standard questionnaires in our institution. Teachers should have a wider knowledge not only in making questions but in methodologies, too. Well, they should vary the strategies or techniques in teaching subject matters to the students so that the discussion given will be remembered always and interesting most of the time. They should be experts and knowledgeable enough in their chosen fields. Once the teacher has the capability to teach, expert on his field, strongly committed and dedicated on his work quality education is not hard to reach. Perhaps, teachers should practice more and enhance more with their skills and abilities through trainings and seminars and absolutely something like these seminars that we had last month. It really helped us to be transformed and create something new with our professions as well. New, that is something different.

April 29, 2009

Mr. Marcwin Dorado Chief Operating Officer System Technology Institute Poblacion, Valencia City THRU: Ms. Louidel Pagas Academic Head System Technology Institute Valencia City Dear Sir: Greetings! I am Ms. Sharon Diana T. Lorono, a full-time Information Technology instructor at STI-Valencia would like to inform the school that I will not sign the contract anymore for the incoming school year 2009-2010 due to some circumstances and this condition

As a part of STI-Valencia for two and half years I would like to extend also my heartfelt gratitude towards the opportunities given by the company. Thank you so much for allowing me to render my service for a short period of time. It really broadened my knowledge and expertise in enhancing my potentials and capabilities in this chosen profession. By working with your organization, the teaching’s prospect is highly appreciated and remains to be remembered whatever chances will come in my way for the incoming months and years. Again, thank you and more power! Sincerely yours,

Ms. Meraflor N. Montajes STI-Valencia Facult Critical Period Hypothesis

The Critical Period Hypothesis refers to a long-standing debate in linguistics and language acquisition over the extent to which the ability to acquire language is biologically linked to age. The hypothesis claims that there is an ideal 'window' of time to acquire language in a linguistically rich environment, after which this is no longer possible. The Critical Period Hypothesis states that the first few years of life is the crucial time in which an individual can acquire a first language if presented with adequate stimuli. If language input doesn't occur until after this time, the individual will never achieve a full command of language — especially grammatical systems. The evidence for such a period is limited, and support stems largely from theoretical arguments and analogies to other critical periods in biology such as visual development, but nonetheless is widely accepted. The nature of this phenomenon, however, has been one of the most fiercely debated issues in psycholinguistics and cognitive science in general for decades. Some writers have suggested a "sensitive" or "optimal" period rather than a critical one; others dispute the causes (physical maturation, cognitive factors). The duration of the period also varies greatly in different accounts. Steven Pinker, in his book The Language Instinct, states that “acquisition of a normal language is guaranteed for children up to the age of six, is steadily compromised from then until shortly after puberty, and is rare thereafter” (Pinker 1994, p. 298). In second language acquisition, the strongest evidence for the critical period hypothesis is in the study of accent, where most older learners do not reach a native-like level. However, under certain conditions, native-like accent has been observed, suggesting that accent is affected by multiple factors, such as identity and motivation, rather than a critical period biological constraint (Moyer, 1999; Bongaerts et al., 1995; Young-Scholten, 2002). •

The Critical Period Hypothesis was first proposed by Montreal neurologist Wilder Penfield and co-author Lamar Roberts in a 1959 paper Speech and Brain Mechanisms, and was popularised by Eric Lenneberg in 1967 with Biological Foundations of Language. Lenneberg proposed brain lateralisation at puberty as the mechanism that closes down the brain's ability to acquire language, though this has since been widely disputed. Other notable proponents of the Critical Period Hypothesis include Noam Chomsky. Linguist Eric Lenneberg (1964) stated that the crucial period of language acquisition ends around the age of 4-5 years. He claimed that if no language is learned before then, it could never be learned in a normal and fully functional sense. This was called the "critical period hypothesis." An interesting example of this is the case of Genie, also known as "The Wild Child". A thirteen-year-old victim of lifelong child abuse, Genie was discovered in her home on November 4th, 1970, strapped to a potty chair and wearing diapers. She appeared to be entirely without language. Her father had judged her retarded at birth and had chosen to isolate her, and so she had remained until her discovery. It was an ideal (albeit horrifying) opportunity to test the theory that a nurturing environment could somehow make up for a total lack of language past the age of 12. She was unable to acquire language completely, although the degree to which she acquired language is disputed.[1] Detractors of the "Critical Period Hypothesis" point out that in this example and others like it (see Feral children), the child is hardly growing up in a nurturing environment, and that the lack of language

acquisition in later life may be due to the results of a generally abusive environment rather than being specifically due to a lack of exposure to language. A more up-to-date view of the Critical Period Hypothesis is represented by the University of Maryland, College Park instructor Robert DeKeyser. DeKeyser argues that although it is true that there is a critical period, this does not mean that adults cannot learn a second language perfectly, at least on the syntactic level. DeKeyser talks about the role of language aptitude as opposed to the critical period.[citation needed] [edit] Second language acquisition The theory has often been extended to a critical period for second language acquisition, although this is much less widely accepted. Certainly, older learners of a second language rarely achieve the native-like fluency that younger learners display, despite often progressing faster than children in the initial stages. David Singleton (1995) states that in learning a second language, "younger = better in the long run," but points out that there are many exceptions, noting that five percent of adult bilinguals master a second language even though they begin learning it when they are well into adulthood — long after any critical period has presumably come to a close. While the window for learning a second language never completely closes, certain linguistic aspects appear to be more affected by the age of the learner than others. For example, adult second-language learners nearly always retain an immediately-identifiable foreign accent, including some who display perfect grammar (Oyama 1976). Some writers have suggested a younger critical age for learning phonology than for syntax. Singleton (1995) reports that there is no critical period for learning vocabulary in a second language. Robertson (2002) observed that factors other than age may be even more significant in successful second language learning, such as personal motivation, anxiety, input and output skills, settings and time commitment. On reviewing the published material, Bialystok and Hakuta (1994) conclude that second-language learning is not necessarily subject to biological critical periods, but "on average, there is a continuous decline in ability [to learn] with age." Experimental and observational studies

How children acquire native language (L1) and the relevance of this to foreign language (L2) learning has long been debated. Although evidence for L2 learning ability declining with age is controversial, a common notion is that children learn L2s easily, whilst older learners rarely achieve fluency. This assumption stems from ‘critical period’ (CP) ideas. A CP was popularised by Eric Lenneberg in 1967 for L1 acquisition, but considerable interest now surrounds age effects on second language acquisition (SLA). SLA theories explain learning processes and suggest causal factors for a possible CP for SLA, mainly attempting to explain apparent differences in language aptitudes of children and adults by distinct learning routes, and clarifying them through psychological mechanisms. Research explores these ideas and hypotheses, but results are varied: some demonstrate pre-pubescent children acquire language easily, and some that older learners have the advantage, whilst others focus on existence of a CP for SLA. Recent studies (e.g. Mayberry and Lock, 2003) have recognised certain aspects of SLA may be affected by age, whilst others remain intact. The objective of this study is to investigate whether capacity for vocabulary acquisition decreases with age.

A review of SLA theories and their explanations for age-related differences is necessary before considering empirical studies. The most reductionist theories are those of Penfield and Roberts (1959) and Lenneberg (1967), which stem from L1 and brain damage studies; children who suffer impairment before puberty typically recover and (re-)develop normal language, whereas adults rarely recover fully, and often do not regain verbal abilities beyond the point reached five months after impairment. Both theories agree that children have a neurological advantage in learning languages, and that puberty correlates with a turning point in ability. They assert that language acquisition occurs primarily, possibly exclusively, during childhood as the brain loses plasticity after a certain age. It then becomes rigid and fixed, and loses the ability for adaptation and reorganisation, rendering language (re-)learning difficult. Penfield and Roberts (1959) claim children under nine can learn up to three languages: early exposure to different languages activates a reflex in the brain allowing them to switch between languages without confusion or translation into L1 (Penfield, 1964). Lenneberg (1967) asserts that if no language is learned by puberty, it cannot be learned in a normal, functional sense. He also supports Penfield and Roberts’ (1959) proposal of neurological mechanisms responsible for maturational change in language learning abilities. This, Lenneberg maintains, coincides with brain lateralisation and left-hemispherical specialisation for language around age thirteen: infants’ motor and linguistic skills develop simultaneously, but by age thirteen the cerebral hemispheres’ functions separate and become set, making language acquisition extremely difficult (Lenneberg, 1967). Cases of deaf and feral children provide evidence for a biologically determined CP for L1. Feral children are those not exposed to language in infancy/childhood due to being brought up in the wild, in isolation and/or confinement. A classic example is 'Genie', who was deprived of social interaction from birth until discovered aged thirteen (post-pubescent). She was completely without language, and after seven years of rehabilitation still lacked linguistic competence. Another case is ‘Isabelle’, who was incarcerated with her deaf-mute mother until the age of six and a half (pre-pubescent). She also had no language skills, but, unlike Genie, quickly acquired normal language abilities through systematic specialist training. Such studies are however problematic; isolation can result in general retardation and emotional disturbances, which may confound conclusions drawn about language abilities. Studies of deaf children learning American Sign Language (ASL) have fewer methodological weaknesses. Newport and Supalla (1987) studied ASL acquisition in deaf children differing in age of exposure; few were exposed to ASL from birth, most of them first learned it at school. Results showed a linear decline in performance with increasing age of exposure; those exposed to ASL from birth performed best, and ‘late learners’ worst, on all production and comprehension tests. Their study thus provides direct evidence for language learning ability decreasing with age, but it does not add to Lennerberg’s CP hypothesis as even the oldest children, the ‘late learners’, were exposed to ASL by age four, and had therefore not reached puberty, the proposed end of the CP. In addition, the declines were shown to be linear, with no sudden ‘drop off’ of ability at a certain age, as would be predicted by a strong CP hypothesis. That the children performed significantly worse, however, suggests the CP may end earlier than originally postulated. Other work has challenged the biological approach; Krashen (1975) reanalysed clinical data used as evidence and concluded cerebral specialisation occurs much earlier than Lenneberg calculated. Therefore, if a CP exists, it does not coincide with lateralisation. Despite concerns with Lenneberg’s original evidence and the dissociation of lateralisation from the language CP idea, however, the concept of a CP remains a viable hypothesis, which later work has better explained and substantiated. Contrary to biological views, behavioural approaches assert that languages are learned as any other behaviour, through conditioning. Skinner (1957) details how operant conditioning forms connections with

the environment through interaction and, alongside O. Hobart Mowrer (1960), applies the ideas to language acquisition. Mowrer hypothesises that languages are acquired through rewarded imitation of ‘language models’; the model must have an emotional link to the learner (e.g. parent, spouse), as imitation then brings pleasant feelings which function as positive reinforcement. Because new connections between behaviour and the environment are formed and reformed throughout life, it is possible to gain new skills, including language(s), at any age. To accommodate observed language learning differences between children and adults, Felix (1985) describes that children, whose brains create countless new connections daily, may handle the language learning process more effectively than do adults. This assumption, however, remains untested and is not a reliable explanation for children’s aptitude for L2 learning. Problematic of the behaviourist approach is its assumption that all learning, verbal and non-verbal, occurs through the same processes. A more general problem is that, as Pinker (1995) notes, almost every sentence anybody voices is an original combination of words, never previously uttered, therefore a language cannot consist only of word combinations learned through repetition and conditioning; the brain must contain innate means of creating endless amounts of grammatical sentences from a limited vocabulary. This is precisely what Chomsky (1965) argues with his proposition of a Universal Grammar (UG). Chomsky (1965) asserts that environmental factors must be relatively unimportant for language emergence, as so many different factors surround children acquiring L1. Instead, Chomsky claims language learners possess innate principles building a ‘language acquisition device’ (LAD) in the brain. These principles denote restricted possibilities for variation within the language, and enable learners to construct a grammar out of ‘raw input’ collected from the environment. Input alone cannot explain language acquisition because it is degenerated by characteristic features such as stutters, and lacks corrections from which learners discover incorrect variations. Singleton and Newport (2004) demonstrate the function of UG in their study of ‘Simon’. Simon learned ASL as his L1 from parents who had learned it as an L2 after puberty and provided him with imperfect models. Results showed Simon learned normal and logical rules and was able to construct an organised linguistic system, despite being exposed to inconsistent input. Chomsky Although Krashen (1975) also criticises this theory, neither discredit the importance of age for second language acquisition. Krashen (1975), and later Felix (1985), proposed theories for the close of the CP for L2 at puberty, based on Piaget’s cognitive stage of formal operations beginning at puberty, as the ‘ability of the formal operational thinker to construct abstract hypotheses to explain phenomena’ inhibits the individual’s natural ability for language learning. The term "language acquisition" became commonly used after Stephen Krashen contrasted it with formal and non-constructive "learning." Today, most scholars use "language learning" and "language acquisition" interchangeably, unless they are directly addressing Krashen's work. However, "second language acquisition" or "SLA" has become established as the preferred term for this academic discipline. Though SLA is often viewed as part of applied linguistics, it is typically concerned with the language system and learning processes themselves, whereas applied linguistics may focus more on the experiences of the learner, particularly in the classroom. Additionally, SLA has mostly examined naturalistic acquisition, where learners acquire a language with little formal training or teaching. •

Critical Period Hypothesis and

Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning. Study on native Korean and Chinese speakers found that the earlier (in age) that the nonnativeEnglish speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition. Support against the CPH, continued… 1.Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. 2. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. 3. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. 4. Problems in second language testing. 5. The role of the learning environment.

6. The role of learner motivation It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time. Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time. Hypothesis Birdsong, David (Ed.) (1999) Mahwah, NJ: Lawrence Erlbaum Associates Is there a single key issue in the field of second language acquisition/learning, an as yet unresolved matter on which all else depends? A good case could be made for the question of whether or not there is a critical period for second language learning being just such a key issue. In other words, does the nature of second language acquisition change if the first exposure to the new language comes after a certain age? This question is closely linked to the question of whether first language (L1) acquisition and second language (L2) acquisition are essentially the same process, or very similar processes, and if so whether this is the case for some learners, or for all. In practical terms, it could be central not only to such issues as the optimal age at which children should start learning foreign languages, but also to the best teaching/learning approach for adults. Krashen's Input Hypothesis (Krashen, 1985) is totally undermined if a critical period does indeed exist, since the hypothesis assumes not only that L2 acquisition is similar in nature to L1 acquisition, but also that this is the case for learners of any age. Alhough many would claim that Krashen's theories are seriously flawed in any case, their influence in the field of second language teaching can hardly be denied. Issues such as the relative importance of lexis and syntax in teaching materials must ultimately link back to the way in which second language knowledge is organised in the brain. If that organisation is different in learners who have first been exposed to L2 after a certain age, then this has a bearing on choice of teaching approach. Yes, I believe there is a strong prima facie case for regarding the debate over the Critical Period Hypothesis (CPH) as a central issue.

The concept of a critical period is well known in nature. One example is imprinting in ducks and geese, where it is claimed that ducklings and goslings can be induced to adopt chickens, people, or even mechanical objects as their mothers if they encounter them within a certain short period after hatching. (Note, however, that the exact nature of even this apparently well-documented instance of a critical period is now coming under fire; see Hoffmann, 1996). In humans, on the basis of extant evidence, it seems that there is a critical period for first language acquisition; those unfortunate persons who are not exposed to any language before puberty seem unable to properly acquire the syntax of their first language later in life. (Inevitably, our knowledge in this area is sketchy and unreliable, being based solely on a very few cases, of which that of "Genie" is the most celebrated and best known; see Eubank and Gregg's article in Birdsong for a discussion.) [-1-] Provided that a person learns a first language in the normal way, the question is then whether there is a certain biologically-determined critical period during which that person can acquire further languages using one mental mechanism, probably resulting in a high level of achievement if learning continues, and after which the learning process for new languages changes, so that the learning outcome will not be as good. Note that we are not talking here about the commonly-observed and widely-accepted generalisation that learning gets harder as one gets older; nor is the question one of whether changes in attitudes or situation alter the learning process as one gets older. The issue is whether a fundamental change in the learning process and thus in potential learning outcomes related to second languages occurs in the brain at a fairly fixed age, closing a biological "window of opportunity" (although as Birdsong points out in his introduction to this book, there is no single formulation of the Critical Period Hypothesis, but a number of different versions of the theory). This book contributes to the debate by juxtaposing a number of papers which consider the CPH from a variety of points of view, and which arrive at a variety of conclusions. Most of the papers in the book are based on talks given at an AILA symposium on the CPH which took place in Finland in 1996. It must have been quite a conference; the names of the contributors to this book make up a Who's Who of researchers in fields related to the CPH issue, and the diversity of the opinions held by the contributors must have made for some sharp exchanges. The book contains research papers by both proponents and opponents of a CPH for SLA, thus drawing the reader into the controversy. What you get in the book is what you might expect from the above description. First, it must be said that it is a fairly tough read. Some of the writers are easier to follow than others, but these are research papers, and anyone unfamiliar with the fields covered--and there is a considerable range of fields--is likely to have to work quite hard at some of the texts at least. Second, there is no overall conclusion, even though the editor does have his own clearly-expressed view. This is not because of differences in the interpretation of data; it is because the various writers operate in different areas of research, each casting a different light on the central issue. These varied areas of research produce conclusions which point in different directions, and because of the lack of common ground on which to debate, the differences cannot easily be resolved. Third, there is an unevenness about the book. Some writers report on tentative conclusions from ongoing research; others simply reproduce material on completed projects which can be found in almost identical form elsewhere. The relevance of the research presented to the central issue also varies. These points might be regarded as drawbacks. But the compensation comes in having so much relevant and fairly up-to-date material on the issue collected together in one volume, providing insights into current knowledge and thinking from a variety of angles. In his introduction, Birdsong briefly surveys the background to the debate, outlining some of the arguments previously advanced for and against the existence of a critical period. He is particularly well suited to this task, having "changed sides" on the issue in the early 1990s. After the background section, Birdsong goes on to present a careful summary of each of the chapters in the book. While admitting his

adherence to the "anti-CPH" camp, he makes no attempt to resolve the evidence presented in the various chapters, and concludes that in total the contributions to the book demonstrate "the richness, depth and breadth of the critical period enquiry" and that they "testify to the unmistakable centrality of the CPH in L2A research" (p. 18). The introduction is clearly written, and since it contains so much summarising material it can stand as a valuable survey of the field in itself. However, some of the chapters in the book do not lend themselves to brief summaries (the chapter by Eubank and Gregg, for example, is far too broad in scope) and thus reading the introduction is no substitute for reading the entire book. [-2-] There are three chapters providing evidence for the existence of an SLA critical period. First, Weber-Fox and Neville take a frontal approach to the issue with an investigation of neural activity while performing L2 tasks in subjects whose first exposure to L2 was at different ages. Their paper has the rather daunting title of "Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioural Evidence in Bilinguals." The findings do not point to the existence of a single critical period; the patterns of change vary for different language tasks. The authors claim, fairly circumspectly, that "our findings are consistent with the hypothesis that the development of at least some neural subsystems for language processing is constrained by maturational changes, even in early childhood. Additionally, our results are compatible, at least in part, with aspects of Lenneberg's . . . original hypothesis that puberty may mark a significant point in language learning capacity and neural reorganization capabilities" (pp. 35-36). Eubank and Gregg, in a wide-ranging paper entitled "Critical Periods and (Second) Language Acquisition: Divide et Impera," recognise the importance of neurological investigation in their consideration of whether second language learners retain access to Universal Grammar, and find Weber-Fox and Neville's line of research a promising one. Sandwiched between these two chapters comes a paper by Hurford and Kirby which takes a very different approach to the problem. The writers' argument is an evolutionary one; they produce computer models to suggest that a critical period for language acquisition finishing at puberty inevitably evolves in order to produce maximum language learning by the time a reproductive age is reached. However, their argument appears predicated on the assumption that the level of an individual's language knowledge governs the likelihood of his or her being able to reproduce. Alas, it has never been my personal experience that linguistic ability provides a crucial advantage in the competition for sexual partners, and I do not find myself convinced in any great measure by this application of the currently fashionable evolutionary approach to exploring the nature of the human mind. Then come three chapters arguing against the existence of a critical period. James Flege provides research evidence to show that level of achievement in pronunciation is closely related to age of first exposure to the second language. He claims that, even for children, the later in life the first exposure to L2, the greater the degree of foreign accent, with no sudden discontinuity in the figures at a certain age to suggest that a critical [-3-] period has ended, a window of opportunity suddenly closed. Other hypotheses, he claims, can be advanced to explain the linear nature of the relationship between age of first exposure and L2 pronunciation, notably that pronunciation of L2 varies as a function of how well one pronounces L1. Theo Bongaerts takes a very different approach in his paper, which again focusses on pronunciation; his view is that people who begin learning L2 later in life can sometimes achieve native-like pronunciation. If such learners do indeed exist, and Bongaerts presents evidence to suggest that they do, then there can be no biological window of learning opportunity that closes at a fixed age; instead, there must be other explanations for the lack of success of the majority of learners. These two papers, then, while arriving at the same conclusion with regard to the existence of an L2 critical period, do so on the basis of more or less contradictory evidence! Finally, Bialystok and Hakuta, focussing primarily on syntax rather than pronunciation, again point to the lack of any age-related discontinuity in the nature of L2 acquisition. They also suggest that belief in a critical period may be the result of misattribution of causality in examining the evidence; even the neurological differences pointed out by Weber-Fox and Neville could be the result of differences in the learning experience, rather than causes of such differences.

This is all somewhat confusing, and the only conclusion that a reader can come to at the end of the book is that there are no easy answers on the CPH. What is clear is that the old notion that the nature of L2 acquisition changes suddenly and dramatically at around the age of 12-13 because of changes in the brain is much too simplistic (as has been generally recognised for some time). If there is any truth in the CPH, then there may be different critical periods for different language skills, different types of change at different ages. If on the other hand there is no physical change in the brain which can be directly related to language learning, other powerful explanations are needed to account for the dramatic decline in ultimate achievement generally seen in later second language learners compared to young children -- and such explanations are no more than tentative guesses at present. None of this is of much immediate help to the practising language teacher; it may even be in the long run that exact age of first L2 exposure and the CPH will not turn out to be such a central issue after all, at least not in a formal learning context. But whether it is itself a key field, or whether it simply takes us into other areas which are key fields, further research into the relationship between age and language learning is likely to help us delve deeper into the mysteries of the mechanisms of second language acquisition.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation.

A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning. Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning.

Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning.

Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning.

Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation.

A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning. Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning.

Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning.

Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning.

Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Critical Period Hypothesis and Second Language Acquisition Many researchers feel that there is a critical period in a human's development in which second language learning may occur, to the extent that the person will be able to speak the additional language at the level of a native speaker. It is believed that after the onset of puberty the critical period has passed and it becomes nearly impossible to learn language to a high degree of proficiency. Here we will take a look at some of the support both in favor of and against the Critical Period Hypothesis.

Support in favor of the CPH: Loss of neural plasticity in the brain with age. Loss of access to the language learning faculty. Maladaptive gain of processing capacity with maturation. A "use it then lose it" philosophy and a "use it or lose it" philosophy. The idea that learning inhibits learning.

Study on native Korean and Chinese speakers found that the earlier (in age) that the non-native English speakers had come to the United States, the better their English proficiency was. Also, speakers who had arrived prior to puberty had the highest levels of proficiency.

Support against the CPH: Krashen's Theories of language acquisition provide alternate hypotheses to explain second language acquisition.

Support against the CPH, continued… Statements supporting CPH misinterpret the facts and, in turn, ignore the findings that older learners acquire a second language more quickly and efficiently. The idea that neurological differences in children and adults are misattributed to differences in second language acquisition and proficiency. Although it is understood that these differences exist, there is not substantial proof that they cause differences in second language acquisition. Undeserved emphasis on unsuccessful adult second language learners, and too little emphasis on older learners who achieve native level proficiency in a second language. Problems in second language testing. The role of the learning environment. The role of learner motivation.

It is my belief, after reviewing data on both sides of the controversy, that a critical period in second language acquisition is not relevant to proficiency level attainment. I think that there are too many variables with strong factual support that explain second language acquisition differences in learners, and too few factual explanations of the critical period theory to warrant its belief. However, due to the relatively recent forays into explaining cognition neurologically, it is possible that future research could yield more substantial support for the critical period hypothesis. I also feel that the study of second language acquisition would

greatly benefit from additional studies examining all possible variables that result in different second language proficiency. Finally, it is my hope that adult learners who wish to tackle a second language are not dissuaded by the prospect of a critical period being passed, because there is just not enough factual evidence to support it at this time.

Second Language Acquisition and the Critical Period describes a waystage--or rather

Second Language Acquisition and the Critical Period Hypothesis Birdsong, David (Ed.) (1999) Mahwah, NJ: Lawrence Erlbaum Associates Pp x + 191 ISBN 0-8058-3084-7 (cloth) US $45.00 (special prepaid price, US $19.95) Is there a single key issue in the field of second language acquisition/learning, an as yet unresolved matter on which all else depends? A good case could be made for the question of whether or not there is a critical period for second language learning being just such a key issue. In other words, does the nature of second language acquisition change if the first exposure to the new language comes after a certain age? This question is closely linked to the question of whether first language (L1) acquisition and second language (L2) acquisition are essentially the same process, or very similar processes, and if so whether this is the case for some learners, or for all. In practical terms, it could be central not only to such issues as the optimal age at which children should start learning foreign languages, but also to the best teaching/learning approach for adults. Krashen's Input Hypothesis (Krashen, 1985) is totally undermined if a critical period does indeed exist, since the hypothesis assumes not only that L2 acquisition is similar in nature to L1 acquisition, but also that this is the case for learners of any age. Alhough many would claim that Krashen's theories are seriously flawed in any case, their influence in the field of second language teaching can hardly be denied. Issues such as the relative importance of lexis and syntax in teaching materials must ultimately link back to the way in which second language knowledge is organised in the brain. If that organisation is different in learners who have first been exposed to L2 after a certain age, then this has a bearing on choice of teaching approach. Yes, I believe there is a strong prima facie case for regarding the debate over the Critical Period Hypothesis (CPH) as a central issue. The concept of a critical period is well known in nature. One example is imprinting in ducks and geese, where it is claimed that ducklings and goslings can be induced to adopt chickens, people, or even mechanical objects as their mothers if they encounter them within a certain short period after hatching. (Note, however, that the exact nature of even this apparently well-documented

instance of a critical period is now coming under fire; see Hoffmann, 1996). In humans, on the basis of extant evidence, it seems that there is a critical period for first language acquisition; those unfortunate persons who are not exposed to any language before puberty seem unable to properly acquire the syntax of their first language later in life. (Inevitably, our knowledge in this area is sketchy and unreliable, being based solely on a very few cases, of which that of "Genie" is the most celebrated and best known; see Eubank and Gregg's article in Birdsong for a discussion.) [-1-] Provided that a person learns a first language in the normal way, the question is then whether there is a certain biologically-determined critical period during which that person can acquire further languages using one mental mechanism, probably resulting in a high level of achievement if learning continues, and after which the learning process for new languages changes, so that the learning outcome will not be as good. Note that we are not talking here about the commonlyobserved and widely-accepted generalisation that learning gets harder as one gets older; nor is the question one of whether changes in attitudes or situation alter the learning process as one gets older. The issue is whether a fundamental change in the learning process and thus in potential learning outcomes related to second languages occurs in the brain at a fairly fixed age, closing a biological "window of opportunity" (although as Birdsong points out in his introduction to this book, there is no single formulation of the Critical Period Hypothesis, but a number of different versions of the theory). This book contributes to the debate by juxtaposing a number of papers which consider the CPH from a variety of points of view, and which arrive at a variety of conclusions. Most of the papers in the book are based on talks given at an AILA symposium on the CPH which took place in Finland in 1996. It must have been quite a conference; the names of the contributors to this book make up a Who's Who of researchers in fields related to the CPH issue, and the diversity of the opinions held by the contributors must have made for some sharp exchanges. The book contains research papers by both proponents and opponents of a CPH for SLA, thus drawing the reader into the controversy. What you get in the book is what you might expect from the above description. First, it must be said that it is a fairly tough read. Some of the writers are easier to follow than others, but these are research papers, and anyone unfamiliar with the fields covered--and there is a considerable range of fields--is likely to have to work quite hard at some of the texts at least. Second, there is no overall conclusion, even though the editor does have his own clearly-expressed view. This is not because of differences in the interpretation of data; it is because the various writers operate in different areas of research, each casting a different light on the central issue. These varied areas of research produce conclusions which point in different directions, and because of the lack of common ground on which to debate, the differences cannot easily be resolved. Third, there is an unevenness about the book. Some writers report on tentative conclusions from ongoing research; others simply reproduce material on completed projects which can be found in almost identical form elsewhere. The relevance of the research presented to the central issue also varies. These points might be regarded as drawbacks. But the compensation comes in having so much relevant and fairly up-to-date material on the issue collected together in one volume, providing insights into current knowledge and thinking from a variety of angles.

In his introduction, Birdsong briefly surveys the background to the debate, outlining some of the arguments previously advanced for and against the existence of a critical period. He is particularly well suited to this task, having "changed sides" on the issue in the early 1990s. After the background section, Birdsong goes on to present a careful summary of each of the chapters in the book. While admitting his adherence to the "anti-CPH" camp, he makes no attempt to resolve the evidence presented in the various chapters, and concludes that in total the contributions to the book demonstrate "the richness, depth and breadth of the critical period enquiry" and that they "testify to the unmistakable centrality of the CPH in L2A research" (p. 18). The introduction is clearly written, and since it contains so much summarising material it can stand as a valuable survey of the field in itself. However, some of the chapters in the book do not lend themselves to brief summaries (the chapter by Eubank and Gregg, for example, is far too broad in scope) and thus reading the introduction is no substitute for reading the entire book. [-2-] There are three chapters providing evidence for the existence of an SLA critical period. First, Weber-Fox and Neville take a frontal approach to the issue with an investigation of neural activity while performing L2 tasks in subjects whose first exposure to L2 was at different ages. Their paper has the rather daunting title of "Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioural Evidence in Bilinguals." The findings do not point to the existence of a single critical period; the patterns of change vary for different language tasks. The authors claim, fairly circumspectly, that "our findings are consistent with the hypothesis that the development of at least some neural subsystems for language processing is constrained by maturational changes, even in early childhood. Additionally, our results are compatible, at least in part, with aspects of Lenneberg's . . . original hypothesis that puberty may mark a significant point in language learning capacity and neural reorganization capabilities" (pp. 35-36). Eubank and Gregg, in a wide-ranging paper entitled "Critical Periods and (Second) Language Acquisition: Divide et Impera," recognise the importance of neurological investigation in their consideration of whether second language learners retain access to Universal Grammar, and find Weber-Fox and Neville's line of research a promising one. Sandwiched between these two chapters comes a paper by Hurford and Kirby which takes a very different approach to the problem. The writers' argument is an evolutionary one; they produce computer models to suggest that a critical period for language acquisition finishing at puberty inevitably evolves in order to produce maximum language learning by the time a reproductive age is reached. However, their argument appears predicated on the assumption that the level of an individual's language knowledge governs the likelihood of his or her being able to reproduce. Alas, it has never been my personal experience that linguistic ability provides a crucial advantage in the competition for sexual partners, and I do not find myself convinced in any great measure by this application of the currently fashionable evolutionary approach to exploring the nature of the human mind. Then come three chapters arguing against the existence of a critical period. James Flege provides research evidence to show that level of achievement in pronunciation is closely related to age of first exposure to the second language. He claims that, even for children, the later in life the first exposure to L2, the greater the degree of foreign accent, with no sudden discontinuity in the figures at a certain age to suggest that a critical [-3-] period has ended, a window of opportunity suddenly closed. Other hypotheses, he claims, can be advanced to explain the linear nature of the relationship between age of first exposure and L2 pronunciation, notably that pronunciation of

L2 varies as a function of how well one pronounces L1. Theo Bongaerts takes a very different approach in his paper, which again focusses on pronunciation; his view is that people who begin learning L2 later in life can sometimes achieve native-like pronunciation. If such learners do indeed exist, and Bongaerts presents evidence to suggest that they do, then there can be no biological window of learning opportunity that closes at a fixed age; instead, there must be other explanations for the lack of success of the majority of learners. These two papers, then, while arriving at the same conclusion with regard to the existence of an L2 critical period, do so on the basis of more or less contradictory evidence! Finally, Bialystok and Hakuta, focussing primarily on syntax rather than pronunciation, again point to the lack of any age-related discontinuity in the nature of L2 acquisition. They also suggest that belief in a critical period may be the result of misattribution of causality in examining the evidence; even the neurological differences pointed out by Weber-Fox and Neville could be the result of differences in the learning experience, rather than causes of such differences. This is all somewhat confusing, and the only conclusion that a reader can come to at the end of the book is that there are no easy answers on the CPH. What is clear is that the old notion that the nature of L2 acquisition changes suddenly and dramatically at around the age of 12-13 because of changes in the brain is much too simplistic (as has been generally recognised for some time). If there is any truth in the CPH, then there may be different critical periods for different language skills, different types of change at different ages. If on the other hand there is no physical change in the brain which can be directly related to language learning, other powerful explanations are needed to account for the dramatic decline in ultimate achievement generally seen in later second language learners compared to young children -- and such explanations are no more than tentative guesses at present. None of this is of much immediate help to the practising language teacher; it may even be in the long run that exact age of first L2 exposure and the CPH will not turn out to be such a central issue after all, at least not in a formal learning context. But whether it is itself a key field, or whether it simply takes us into other areas which are key fields, further research into the relationship between age and language learning is likely to help us delve deeper into the mysteries of the mechanisms of second language acquisition. Birdsong's collection of papers describes a waystage--or rather

Second Language Acquisition and the Critical Period Hypothesis Birdsong, David (Ed.) (1999) Mahwah, NJ: Lawrence Erlbaum Associates Pp x + 191 ISBN 0-8058-3084-7 (cloth) US $45.00 (special prepaid price, US $19.95) Is there a single key issue in the field of second language acquisition/learning, an as yet unresolved matter on which all else depends? A good case could be made for the question of whether or not there is a critical period for second language learning being just such a key issue. In other words, does the nature of second language acquisition change if the first exposure to the

new language comes after a certain age? This question is closely linked to the question of whether first language (L1) acquisition and second language (L2) acquisition are essentially the same process, or very similar processes, and if so whether this is the case for some learners, or for all. In practical terms, it could be central not only to such issues as the optimal age at which children should start learning foreign languages, but also to the best teaching/learning approach for adults. Krashen's Input Hypothesis (Krashen, 1985) is totally undermined if a critical period does indeed exist, since the hypothesis assumes not only that L2 acquisition is similar in nature to L1 acquisition, but also that this is the case for learners of any age. Alhough many would claim that Krashen's theories are seriously flawed in any case, their influence in the field of second language teaching can hardly be denied. Issues such as the relative importance of lexis and syntax in teaching materials must ultimately link back to the way in which second language knowledge is organised in the brain. If that organisation is different in learners who have first been exposed to L2 after a certain age, then this has a bearing on choice of teaching approach. Yes, I believe there is a strong prima facie case for regarding the debate over the Critical Period Hypothesis (CPH) as a central issue. The concept of a critical period is well known in nature. One example is imprinting in ducks and geese, where it is claimed that ducklings and goslings can be induced to adopt chickens, people, or even mechanical objects as their mothers if they encounter them within a certain short period after hatching. (Note, however, that the exact nature of even this apparently well-documented instance of a critical period is now coming under fire; see Hoffmann, 1996). In humans, on the basis of extant evidence, it seems that there is a critical period for first language acquisition; those unfortunate persons who are not exposed to any language before puberty seem unable to properly acquire the syntax of their first language later in life. (Inevitably, our knowledge in this area is sketchy and unreliable, being based solely on a very few cases, of which that of "Genie" is the most celebrated and best known; see Eubank and Gregg's article in Birdsong for a discussion.) [-1-] Provided that a person learns a first language in the normal way, the question is then whether there is a certain biologically-determined critical period during which that person can acquire further languages using one mental mechanism, probably resulting in a high level of achievement if learning continues, and after which the learning process for new languages changes, so that the learning outcome will not be as good. Note that we are not talking here about the commonlyobserved and widely-accepted generalisation that learning gets harder as one gets older; nor is the question one of whether changes in attitudes or situation alter the learning process as one gets older. The issue is whether a fundamental change in the learning process and thus in potential learning outcomes related to second languages occurs in the brain at a fairly fixed age, closing a biological "window of opportunity" (although as Birdsong points out in his introduction to this book, there is no single formulation of the Critical Period Hypothesis, but a number of different versions of the theory). This book contributes to the debate by juxtaposing a number of papers which consider the CPH from a variety of points of view, and which arrive at a variety of conclusions. Most of the papers in the book are based on talks given at an AILA symposium on the CPH which took place in Finland in 1996. It must have been quite a conference; the names of the contributors to this book make up a Who's Who of researchers in fields related to the CPH issue, and the diversity of the

opinions held by the contributors must have made for some sharp exchanges. The book contains research papers by both proponents and opponents of a CPH for SLA, thus drawing the reader into the controversy. What you get in the book is what you might expect from the above description. First, it must be said that it is a fairly tough read. Some of the writers are easier to follow than others, but these are research papers, and anyone unfamiliar with the fields covered--and there is a considerable range of fields--is likely to have to work quite hard at some of the texts at least. Second, there is no overall conclusion, even though the editor does have his own clearly-expressed view. This is not because of differences in the interpretation of data; it is because the various writers operate in different areas of research, each casting a different light on the central issue. These varied areas of research produce conclusions which point in different directions, and because of the lack of common ground on which to debate, the differences cannot easily be resolved. Third, there is an unevenness about the book. Some writers report on tentative conclusions from ongoing research; others simply reproduce material on completed projects which can be found in almost identical form elsewhere. The relevance of the research presented to the central issue also varies. These points might be regarded as drawbacks. But the compensation comes in having so much relevant and fairly up-to-date material on the issue collected together in one volume, providing insights into current knowledge and thinking from a variety of angles. In his introduction, Birdsong briefly surveys the background to the debate, outlining some of the arguments previously advanced for and against the existence of a critical period. He is particularly well suited to this task, having "changed sides" on the issue in the early 1990s. After the background section, Birdsong goes on to present a careful summary of each of the chapters in the book. While admitting his adherence to the "anti-CPH" camp, he makes no attempt to resolve the evidence presented in the various chapters, and concludes that in total the contributions to the book demonstrate "the richness, depth and breadth of the critical period enquiry" and that they "testify to the unmistakable centrality of the CPH in L2A research" (p. 18). The introduction is clearly written, and since it contains so much summarising material it can stand as a valuable survey of the field in itself. However, some of the chapters in the book do not lend themselves to brief summaries (the chapter by Eubank and Gregg, for example, is far too broad in scope) and thus reading the introduction is no substitute for reading the entire book. [-2-] There are three chapters providing evidence for the existence of an SLA critical period. First, Weber-Fox and Neville take a frontal approach to the issue with an investigation of neural activity while performing L2 tasks in subjects whose first exposure to L2 was at different ages. Their paper has the rather daunting title of "Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioural Evidence in Bilinguals." The findings do not point to the existence of a single critical period; the patterns of change vary for different language tasks. The authors claim, fairly circumspectly, that "our findings are consistent with the hypothesis that the development of at least some neural subsystems for language processing is constrained by maturational changes, even in early childhood. Additionally, our results are compatible, at least in part, with aspects of Lenneberg's . . . original hypothesis that puberty may mark a significant point in language learning capacity and neural reorganization capabilities" (pp. 35-36). Eubank and Gregg, in a wide-ranging paper entitled "Critical Periods and (Second) Language Acquisition: Divide et Impera," recognise the

importance of neurological investigation in their consideration of whether second language learners retain access to Universal Grammar, and find Weber-Fox and Neville's line of research a promising one. Sandwiched between these two chapters comes a paper by Hurford and Kirby which takes a very different approach to the problem. The writers' argument is an evolutionary one; they produce computer models to suggest that a critical period for language acquisition finishing at puberty inevitably evolves in order to produce maximum language learning by the time a reproductive age is reached. However, their argument appears predicated on the assumption that the level of an individual's language knowledge governs the likelihood of his or her being able to reproduce. Alas, it has never been my personal experience that linguistic ability provides a crucial advantage in the competition for sexual partners, and I do not find myself convinced in any great measure by this application of the currently fashionable evolutionary approach to exploring the nature of the human mind. Then come three chapters arguing against the existence of a critical period. James Flege provides research evidence to show that level of achievement in pronunciation is closely related to age of first exposure to the second language. He claims that, even for children, the later in life the first exposure to L2, the greater the degree of foreign accent, with no sudden discontinuity in the figures at a certain age to suggest that a critical [-3-] period has ended, a window of opportunity suddenly closed. Other hypotheses, he claims, can be advanced to explain the linear nature of the relationship between age of first exposure and L2 pronunciation, notably that pronunciation of L2 varies as a function of how well one pronounces L1. Theo Bongaerts takes a very different approach in his paper, which again focusses on pronunciation; his view is that people who begin learning L2 later in life can sometimes achieve native-like pronunciation. If such learners do indeed exist, and Bongaerts presents evidence to suggest that they do, then there can be no biological window of learning opportunity that closes at a fixed age; instead, there must be other explanations for the lack of success of the majority of learners. These two papers, then, while arriving at the same conclusion with regard to the existence of an L2 critical period, do so on the basis of more or less contradictory evidence! Finally, Bialystok and Hakuta, focussing primarily on syntax rather than pronunciation, again point to the lack of any age-related discontinuity in the nature of L2 acquisition. They also suggest that belief in a critical period may be the result of misattribution of causality in examining the evidence; even the neurological differences pointed out by Weber-Fox and Neville could be the result of differences in the learning experience, rather than causes of such differences. This is all somewhat confusing, and the only conclusion that a reader can come to at the end of the book is that there are no easy answers on the CPH. What is clear is that the old notion that the nature of L2 acquisition changes suddenly and dramatically at around the age of 12-13 because of changes in the brain is much too simplistic (as has been generally recognised for some time). If there is any truth in the CPH, then there may be different critical periods for different language skills, different types of change at different ages. If on the other hand there is no physical change in the brain which can be directly related to language learning, other powerful explanations are needed to account for the dramatic decline in ultimate achievement generally seen in later second language learners compared to young children -- and such explanations are no more than tentative guesses at present. None of this is of much immediate help to the practising language teacher; it may even be in the long run that exact age of first L2 exposure and the CPH will not turn out to be such a central issue after all, at least not in a formal learning context. But whether

it is itself a key field, or whether it simply takes us into other areas which are key fields, further research into the relationship between age and language learning is likely to help us delve deeper into the mysteries of the mechanisms of second language acquisition. Birdsong's collection of papers describes a waystage--or rather

Second Language Acquisition and the Critical Period Hypothesis Birdsong, David (Ed.) (1999) Mahwah, NJ: Lawrence Erlbaum Associates Pp x + 191 ISBN 0-8058-3084-7 (cloth) US $45.00 (special prepaid price, US $19.95) Is there a single key issue in the field of second language acquisition/learning, an as yet unresolved matter on which all else depends? A good case could be made for the question of whether or not there is a critical period for second language learning being just such a key issue. In other words, does the nature of second language acquisition change if the first exposure to the new language comes after a certain age? This question is closely linked to the question of whether first language (L1) acquisition and second language (L2) acquisition are essentially the same process, or very similar processes, and if so whether this is the case for some learners, or for all. In practical terms, it could be central not only to such issues as the optimal age at which children should start learning foreign languages, but also to the best teaching/learning approach for adults. Krashen's Input Hypothesis (Krashen, 1985) is totally undermined if a critical period does indeed exist, since the hypothesis assumes not only that L2 acquisition is similar in nature to L1 acquisition, but also that this is the case for learners of any age. Alhough many would claim that Krashen's theories are seriously flawed in any case, their influence in the field of second language teaching can hardly be denied. Issues such as the relative importance of lexis and syntax in teaching materials must ultimately link back to the way in which second language knowledge is organised in the brain. If that organisation is different in learners who have first been exposed to L2 after a certain age, then this has a bearing on choice of teaching approach. Yes, I believe there is a strong prima facie case for regarding the debate over the Critical Period Hypothesis (CPH) as a central issue. The concept of a critical period is well known in nature. One example is imprinting in ducks and geese, where it is claimed that ducklings and goslings can be induced to adopt chickens, people, or even mechanical objects as their mothers if they encounter them within a certain short period after hatching. (Note, however, that the exact nature of even this apparently well-documented instance of a critical period is now coming under fire; see Hoffmann, 1996). In humans, on the basis of extant evidence, it seems that there is a critical period for first language acquisition; those unfortunate persons who are not exposed to any language before puberty seem unable to properly acquire the syntax of their first language later in life. (Inevitably, our knowledge in this area is sketchy and unreliable, being based solely on a very few cases, of which that of "Genie"

is the most celebrated and best known; see Eubank and Gregg's article in Birdsong for a discussion.) [-1-] Provided that a person learns a first language in the normal way, the question is then whether there is a certain biologically-determined critical period during which that person can acquire further languages using one mental mechanism, probably resulting in a high level of achievement if learning continues, and after which the learning process for new languages changes, so that the learning outcome will not be as good. Note that we are not talking here about the commonlyobserved and widely-accepted generalisation that learning gets harder as one gets older; nor is the question one of whether changes in attitudes or situation alter the learning process as one gets older. The issue is whether a fundamental change in the learning process and thus in potential learning outcomes related to second languages occurs in the brain at a fairly fixed age, closing a biological "window of opportunity" (although as Birdsong points out in his introduction to this book, there is no single formulation of the Critical Period Hypothesis, but a number of different versions of the theory). This book contributes to the debate by juxtaposing a number of papers which consider the CPH from a variety of points of view, and which arrive at a variety of conclusions. Most of the papers in the book are based on talks given at an AILA symposium on the CPH which took place in Finland in 1996. It must have been quite a conference; the names of the contributors to this book make up a Who's Who of researchers in fields related to the CPH issue, and the diversity of the opinions held by the contributors must have made for some sharp exchanges. The book contains research papers by both proponents and opponents of a CPH for SLA, thus drawing the reader into the controversy. What you get in the book is what you might expect from the above description. First, it must be said that it is a fairly tough read. Some of the writers are easier to follow than others, but these are research papers, and anyone unfamiliar with the fields covered--and there is a considerable range of fields--is likely to have to work quite hard at some of the texts at least. Second, there is no overall conclusion, even though the editor does have his own clearly-expressed view. This is not because of differences in the interpretation of data; it is because the various writers operate in different areas of research, each casting a different light on the central issue. These varied areas of research produce conclusions which point in different directions, and because of the lack of common ground on which to debate, the differences cannot easily be resolved. Third, there is an unevenness about the book. Some writers report on tentative conclusions from ongoing research; others simply reproduce material on completed projects which can be found in almost identical form elsewhere. The relevance of the research presented to the central issue also varies. These points might be regarded as drawbacks. But the compensation comes in having so much relevant and fairly up-to-date material on the issue collected together in one volume, providing insights into current knowledge and thinking from a variety of angles. In his introduction, Birdsong briefly surveys the background to the debate, outlining some of the arguments previously advanced for and against the existence of a critical period. He is particularly well suited to this task, having "changed sides" on the issue in the early 1990s. After the background section, Birdsong goes on to present a careful summary of each of the chapters in the book. While admitting his adherence to the "anti-CPH" camp, he makes no attempt to resolve

the evidence presented in the various chapters, and concludes that in total the contributions to the book demonstrate "the richness, depth and breadth of the critical period enquiry" and that they "testify to the unmistakable centrality of the CPH in L2A research" (p. 18). The introduction is clearly written, and since it contains so much summarising material it can stand as a valuable survey of the field in itself. However, some of the chapters in the book do not lend themselves to brief summaries (the chapter by Eubank and Gregg, for example, is far too broad in scope) and thus reading the introduction is no substitute for reading the entire book. [-2-] There are three chapters providing evidence for the existence of an SLA critical period. First, Weber-Fox and Neville take a frontal approach to the issue with an investigation of neural activity while performing L2 tasks in subjects whose first exposure to L2 was at different ages. Their paper has the rather daunting title of "Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioural Evidence in Bilinguals." The findings do not point to the existence of a single critical period; the patterns of change vary for different language tasks. The authors claim, fairly circumspectly, that "our findings are consistent with the hypothesis that the development of at least some neural subsystems for language processing is constrained by maturational changes, even in early childhood. Additionally, our results are compatible, at least in part, with aspects of Lenneberg's . . . original hypothesis that puberty may mark a significant point in language learning capacity and neural reorganization capabilities" (pp. 35-36). Eubank and Gregg, in a wide-ranging paper entitled "Critical Periods and (Second) Language Acquisition: Divide et Impera," recognise the importance of neurological investigation in their consideration of whether second language learners retain access to Universal Grammar, and find Weber-Fox and Neville's line of research a promising one. Sandwiched between these two chapters comes a paper by Hurford and Kirby which takes a very different approach to the problem. The writers' argument is an evolutionary one; they produce computer models to suggest that a critical period for language acquisition finishing at puberty inevitably evolves in order to produce maximum language learning by the time a reproductive age is reached. However, their argument appears predicated on the assumption that the level of an individual's language knowledge governs the likelihood of his or her being able to reproduce. Alas, it has never been my personal experience that linguistic ability provides a crucial advantage in the competition for sexual partners, and I do not find myself convinced in any great measure by this application of the currently fashionable evolutionary approach to exploring the nature of the human mind. Then come three chapters arguing against the existence of a critical period. James Flege provides research evidence to show that level of achievement in pronunciation is closely related to age of first exposure to the second language. He claims that, even for children, the later in life the first exposure to L2, the greater the degree of foreign accent, with no sudden discontinuity in the figures at a certain age to suggest that a critical [-3-] period has ended, a window of opportunity suddenly closed. Other hypotheses, he claims, can be advanced to explain the linear nature of the relationship between age of first exposure and L2 pronunciation, notably that pronunciation of L2 varies as a function of how well one pronounces L1. Theo Bongaerts takes a very different approach in his paper, which again focusses on pronunciation; his view is that people who begin learning L2 later in life can sometimes achieve native-like pronunciation. If such learners do indeed exist, and Bongaerts presents evidence to suggest that they do, then there can be no biological window of learning opportunity that closes at a fixed age; instead, there must be other

explanations for the lack of success of the majority of learners. These two papers, then, while arriving at the same conclusion with regard to the existence of an L2 critical period, do so on the basis of more or less contradictory evidence! Finally, Bialystok and Hakuta, focussing primarily on syntax rather than pronunciation, again point to the lack of any age-related discontinuity in the nature of L2 acquisition. They also suggest that belief in a critical period may be the result of misattribution of causality in examining the evidence; even the neurological differences pointed out by Weber-Fox and Neville could be the result of differences in the learning experience, rather than causes of such differences. This is all somewhat confusing, and the only conclusion that a reader can come to at the end of the book is that there are no easy answers on the CPH. What is clear is that the old notion that the nature of L2 acquisition changes suddenly and dramatically at around the age of 12-13 because of changes in the brain is much too simplistic (as has been generally recognised for some time). If there is any truth in the CPH, then there may be different critical periods for different language skills, different types of change at different ages. If on the other hand there is no physical change in the brain which can be directly related to language learning, other powerful explanations are needed to account for the dramatic decline in ultimate achievement generally seen in later second language learners compared to young children -- and such explanations are no more than tentative guesses at present. None of this is of much immediate help to the practising language teacher; it may even be in the long run that exact age of first L2 exposure and the CPH will not turn out to be such a central issue after all, at least not in a formal learning context. But whether it is itself a key field, or whether it simply takes us into other areas which are key fields, further research into the relationship between age and language learning is likely to help us delve deeper into the mysteries of the mechanisms of second language acquisition. Birdsong's collection of papers describes a waystage--or rather

Second Language Acquisition and the Critical Period Hypothesis Birdsong, David (Ed.) (1999) Mahwah, NJ: Lawrence Erlbaum Associates Pp x + 191 ISBN 0-8058-3084-7 (cloth) US $45.00 (special prepaid price, US $19.95) Is there a single key issue in the field of second language acquisition/learning, an as yet unresolved matter on which all else depends? A good case could be made for the question of whether or not there is a critical period for second language learning being just such a key issue. In other words, does the nature of second language acquisition change if the first exposure to the new language comes after a certain age? This question is closely linked to the question of whether first language (L1) acquisition and second language (L2) acquisition are essentially the same process, or very similar processes, and if so whether this is the case for some learners, or for all. In practical terms, it could be central not only to such issues as the optimal age at which children should start learning foreign languages, but also to the best teaching/learning approach

for adults. Krashen's Input Hypothesis (Krashen, 1985) is totally undermined if a critical period does indeed exist, since the hypothesis assumes not only that L2 acquisition is similar in nature to L1 acquisition, but also that this is the case for learners of any age. Alhough many would claim that Krashen's theories are seriously flawed in any case, their influence in the field of second language teaching can hardly be denied. Issues such as the relative importance of lexis and syntax in teaching materials must ultimately link back to the way in which second language knowledge is organised in the brain. If that organisation is different in learners who have first been exposed to L2 after a certain age, then this has a bearing on choice of teaching approach. Yes, I believe there is a strong prima facie case for regarding the debate over the Critical Period Hypothesis (CPH) as a central issue. The concept of a critical period is well known in nature. One example is imprinting in ducks and geese, where it is claimed that ducklings and goslings can be induced to adopt chickens, people, or even mechanical objects as their mothers if they encounter them within a certain short period after hatching. (Note, however, that the exact nature of even this apparently well-documented instance of a critical period is now coming under fire; see Hoffmann, 1996). In humans, on the basis of extant evidence, it seems that there is a critical period for first language acquisition; those unfortunate persons who are not exposed to any language before puberty seem unable to properly acquire the syntax of their first language later in life. (Inevitably, our knowledge in this area is sketchy and unreliable, being based solely on a very few cases, of which that of "Genie" is the most celebrated and best known; see Eubank and Gregg's article in Birdsong for a discussion.) [-1-] Provided that a person learns a first language in the normal way, the question is then whether there is a certain biologically-determined critical period during which that person can acquire further languages using one mental mechanism, probably resulting in a high level of achievement if learning continues, and after which the learning process for new languages changes, so that the learning outcome will not be as good. Note that we are not talking here about the commonlyobserved and widely-accepted generalisation that learning gets harder as one gets older; nor is the question one of whether changes in attitudes or situation alter the learning process as one gets older. The issue is whether a fundamental change in the learning process and thus in potential learning outcomes related to second languages occurs in the brain at a fairly fixed age, closing a biological "window of opportunity" (although as Birdsong points out in his introduction to this book, there is no single formulation of the Critical Period Hypothesis, but a number of different versions of the theory). This book contributes to the debate by juxtaposing a number of papers which consider the CPH from a variety of points of view, and which arrive at a variety of conclusions. Most of the papers in the book are based on talks given at an AILA symposium on the CPH which took place in Finland in 1996. It must have been quite a conference; the names of the contributors to this book make up a Who's Who of researchers in fields related to the CPH issue, and the diversity of the opinions held by the contributors must have made for some sharp exchanges. The book contains research papers by both proponents and opponents of a CPH for SLA, thus drawing the reader into the controversy.

What you get in the book is what you might expect from the above description. First, it must be said that it is a fairly tough read. Some of the writers are easier to follow than others, but these are research papers, and anyone unfamiliar with the fields covered--and there is a considerable range of fields--is likely to have to work quite hard at some of the texts at least. Second, there is no overall conclusion, even though the editor does have his own clearly-expressed view. This is not because of differences in the interpretation of data; it is because the various writers operate in different areas of research, each casting a different light on the central issue. These varied areas of research produce conclusions which point in different directions, and because of the lack of common ground on which to debate, the differences cannot easily be resolved. Third, there is an unevenness about the book. Some writers report on tentative conclusions from ongoing research; others simply reproduce material on completed projects which can be found in almost identical form elsewhere. The relevance of the research presented to the central issue also varies. These points might be regarded as drawbacks. But the compensation comes in having so much relevant and fairly up-to-date material on the issue collected together in one volume, providing insights into current knowledge and thinking from a variety of angles. In his introduction, Birdsong briefly surveys the background to the debate, outlining some of the arguments previously advanced for and against the existence of a critical period. He is particularly well suited to this task, having "changed sides" on the issue in the early 1990s. After the background section, Birdsong goes on to present a careful summary of each of the chapters in the book. While admitting his adherence to the "anti-CPH" camp, he makes no attempt to resolve the evidence presented in the various chapters, and concludes that in total the contributions to the book demonstrate "the richness, depth and breadth of the critical period enquiry" and that they "testify to the unmistakable centrality of the CPH in L2A research" (p. 18). The introduction is clearly written, and since it contains so much summarising material it can stand as a valuable survey of the field in itself. However, some of the chapters in the book do not lend themselves to brief summaries (the chapter by Eubank and Gregg, for example, is far too broad in scope) and thus reading the introduction is no substitute for reading the entire book. [-2-] There are three chapters providing evidence for the existence of an SLA critical period. First, Weber-Fox and Neville take a frontal approach to the issue with an investigation of neural activity while performing L2 tasks in subjects whose first exposure to L2 was at different ages. Their paper has the rather daunting title of "Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioural Evidence in Bilinguals." The findings do not point to the existence of a single critical period; the patterns of change vary for different language tasks. The authors claim, fairly circumspectly, that "our findings are consistent with the hypothesis that the development of at least some neural subsystems for language processing is constrained by maturational changes, even in early childhood. Additionally, our results are compatible, at least in part, with aspects of Lenneberg's . . . original hypothesis that puberty may mark a significant point in language learning capacity and neural reorganization capabilities" (pp. 35-36). Eubank and Gregg, in a wide-ranging paper entitled "Critical Periods and (Second) Language Acquisition: Divide et Impera," recognise the importance of neurological investigation in their consideration of whether second language learners retain access to Universal Grammar, and find Weber-Fox and Neville's line of research a promising one. Sandwiched between these two chapters comes a paper by Hurford and Kirby which takes a very different approach to the problem. The writers' argument is an evolutionary

one; they produce computer models to suggest that a critical period for language acquisition finishing at puberty inevitably evolves in order to produce maximum language learning by the time a reproductive age is reached. However, their argument appears predicated on the assumption that the level of an individual's language knowledge governs the likelihood of his or her being able to reproduce. Alas, it has never been my personal experience that linguistic ability provides a crucial advantage in the competition for sexual partners, and I do not find myself convinced in any great measure by this application of the currently fashionable evolutionary approach to exploring the nature of the human mind. Then come three chapters arguing against the existence of a critical period. James Flege provides research evidence to show that level of achievement in pronunciation is closely related to age of first exposure to the second language. He claims that, even for children, the later in life the first exposure to L2, the greater the degree of foreign accent, with no sudden discontinuity in the figures at a certain age to suggest that a critical [-3-] period has ended, a window of opportunity suddenly closed. Other hypotheses, he claims, can be advanced to explain the linear nature of the relationship between age of first exposure and L2 pronunciation, notably that pronunciation of L2 varies as a function of how well one pronounces L1. Theo Bongaerts takes a very different approach in his paper, which again focusses on pronunciation; his view is that people who begin learning L2 later in life can sometimes achieve native-like pronunciation. If such learners do indeed exist, and Bongaerts presents evidence to suggest that they do, then there can be no biological window of learning opportunity that closes at a fixed age; instead, there must be other explanations for the lack of success of the majority of learners. These two papers, then, while arriving at the same conclusion with regard to the existence of an L2 critical period, do so on the basis of more or less contradictory evidence! Finally, Bialystok and Hakuta, focussing primarily on syntax rather than pronunciation, again point to the lack of any age-related discontinuity in the nature of L2 acquisition. They also suggest that belief in a critical period may be the result of misattribution of causality in examining the evidence; even the neurological differences pointed out by Weber-Fox and Neville could be the result of differences in the learning experience, rather than causes of such differences. This is all somewhat confusing, and the only conclusion that a reader can come to at the end of the book is that there are no easy answers on the CPH. What is clear is that the old notion that the nature of L2 acquisition changes suddenly and dramatically at around the age of 12-13 because of changes in the brain is much too simplistic (as has been generally recognised for some time). If there is any truth in the CPH, then there may be different critical periods for different language skills, different types of change at different ages. If on the other hand there is no physical change in the brain which can be directly related to language learning, other powerful explanations are needed to account for the dramatic decline in ultimate achievement generally seen in later second language learners compared to young children -- and such explanations are no more than tentative guesses at present. None of this is of much immediate help to the practising language teacher; it may even be in the long run that exact age of first L2 exposure and the CPH will not turn out to be such a central issue after all, at least not in a formal learning context. But whether it is itself a key field, or whether it simply takes us into other areas which are key fields, further research into the relationship between age and language learning is likely to help us delve deeper into the mysteries of the mechanisms of second language acquisition.

Birdsong's collection of papers describes a waystage--or rather

Second Language Acquisition and the Critical Period Hypothesis Birdsong, David (Ed.) (1999) Mahwah, NJ: Lawrence Erlbaum Associates Pp x + 191 ISBN 0-8058-3084-7 (cloth) US $45.00 (special prepaid price, US $19.95) Is there a single key issue in the field of second language acquisition/learning, an as yet unresolved matter on which all else depends? A good case could be made for the question of whether or not there is a critical period for second language learning being just such a key issue. In other words, does the nature of second language acquisition change if the first exposure to the new language comes after a certain age? This question is closely linked to the question of whether first language (L1) acquisition and second language (L2) acquisition are essentially the same process, or very similar processes, and if so whether this is the case for some learners, or for all. In practical terms, it could be central not only to such issues as the optimal age at which children should start learning foreign languages, but also to the best teaching/learning approach for adults. Krashen's Input Hypothesis (Krashen, 1985) is totally undermined if a critical period does indeed exist, since the hypothesis assumes not only that L2 acquisition is similar in nature to L1 acquisition, but also that this is the case for learners of any age. Alhough many would claim that Krashen's theories are seriously flawed in any case, their influence in the field of second language teaching can hardly be denied. Issues such as the relative importance of lexis and syntax in teaching materials must ultimately link back to the way in which second language knowledge is organised in the brain. If that organisation is different in learners who have first been exposed to L2 after a certain age, then this has a bearing on choice of teaching approach. Yes, I believe there is a strong prima facie case for regarding the debate over the Critical Period Hypothesis (CPH) as a central issue. The concept of a critical period is well known in nature. One example is imprinting in ducks and geese, where it is claimed that ducklings and goslings can be induced to adopt chickens, people, or even mechanical objects as their mothers if they encounter them within a certain short period after hatching. (Note, however, that the exact nature of even this apparently well-documented instance of a critical period is now coming under fire; see Hoffmann, 1996). In humans, on the basis of extant evidence, it seems that there is a critical period for first language acquisition; those unfortunate persons who are not exposed to any language before puberty seem unable to properly acquire the syntax of their first language later in life. (Inevitably, our knowledge in this area is sketchy and unreliable, being based solely on a very few cases, of which that of "Genie" is the most celebrated and best known; see Eubank and Gregg's article in Birdsong for a discussion.) [-1-] Provided that a person learns a first language in the normal way, the question is then whether there is a certain biologically-determined critical period during which that person can acquire

further languages using one mental mechanism, probably resulting in a high level of achievement if learning continues, and after which the learning process for new languages changes, so that the learning outcome will not be as good. Note that we are not talking here about the commonlyobserved and widely-accepted generalisation that learning gets harder as one gets older; nor is the question one of whether changes in attitudes or situation alter the learning process as one gets older. The issue is whether a fundamental change in the learning process and thus in potential learning outcomes related to second languages occurs in the brain at a fairly fixed age, closing a biological "window of opportunity" (although as Birdsong points out in his introduction to this book, there is no single formulation of the Critical Period Hypothesis, but a number of different versions of the theory). This book contributes to the debate by juxtaposing a number of papers which consider the CPH from a variety of points of view, and which arrive at a variety of conclusions. Most of the papers in the book are based on talks given at an AILA symposium on the CPH which took place in Finland in 1996. It must have been quite a conference; the names of the contributors to this book make up a Who's Who of researchers in fields related to the CPH issue, and the diversity of the opinions held by the contributors must have made for some sharp exchanges. The book contains research papers by both proponents and opponents of a CPH for SLA, thus drawing the reader into the controversy. What you get in the book is what you might expect from the above description. First, it must be said that it is a fairly tough read. Some of the writers are easier to follow than others, but these are research papers, and anyone unfamiliar with the fields covered--and there is a considerable range of fields--is likely to have to work quite hard at some of the texts at least. Second, there is no overall conclusion, even though the editor does have his own clearly-expressed view. This is not because of differences in the interpretation of data; it is because the various writers operate in different areas of research, each casting a different light on the central issue. These varied areas of research produce conclusions which point in different directions, and because of the lack of common ground on which to debate, the differences cannot easily be resolved. Third, there is an unevenness about the book. Some writers report on tentative conclusions from ongoing research; others simply reproduce material on completed projects which can be found in almost identical form elsewhere. The relevance of the research presented to the central issue also varies. These points might be regarded as drawbacks. But the compensation comes in having so much relevant and fairly up-to-date material on the issue collected together in one volume, providing insights into current knowledge and thinking from a variety of angles. In his introduction, Birdsong briefly surveys the background to the debate, outlining some of the arguments previously advanced for and against the existence of a critical period. He is particularly well suited to this task, having "changed sides" on the issue in the early 1990s. After the background section, Birdsong goes on to present a careful summary of each of the chapters in the book. While admitting his adherence to the "anti-CPH" camp, he makes no attempt to resolve the evidence presented in the various chapters, and concludes that in total the contributions to the book demonstrate "the richness, depth and breadth of the critical period enquiry" and that they "testify to the unmistakable centrality of the CPH in L2A research" (p. 18). The introduction is clearly written, and since it contains so much summarising material it can stand as a valuable survey of the field in itself. However, some of the chapters in the book do not lend themselves to

brief summaries (the chapter by Eubank and Gregg, for example, is far too broad in scope) and thus reading the introduction is no substitute for reading the entire book. [-2-] There are three chapters providing evidence for the existence of an SLA critical period. First, Weber-Fox and Neville take a frontal approach to the issue with an investigation of neural activity while performing L2 tasks in subjects whose first exposure to L2 was at different ages. Their paper has the rather daunting title of "Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioural Evidence in Bilinguals." The findings do not point to the existence of a single critical period; the patterns of change vary for different language tasks. The authors claim, fairly circumspectly, that "our findings are consistent with the hypothesis that the development of at least some neural subsystems for language processing is constrained by maturational changes, even in early childhood. Additionally, our results are compatible, at least in part, with aspects of Lenneberg's . . . original hypothesis that puberty may mark a significant point in language learning capacity and neural reorganization capabilities" (pp. 35-36). Eubank and Gregg, in a wide-ranging paper entitled "Critical Periods and (Second) Language Acquisition: Divide et Impera," recognise the importance of neurological investigation in their consideration of whether second language learners retain access to Universal Grammar, and find Weber-Fox and Neville's line of research a promising one. Sandwiched between these two chapters comes a paper by Hurford and Kirby which takes a very different approach to the problem. The writers' argument is an evolutionary one; they produce computer models to suggest that a critical period for language acquisition finishing at puberty inevitably evolves in order to produce maximum language learning by the time a reproductive age is reached. However, their argument appears predicated on the assumption that the level of an individual's language knowledge governs the likelihood of his or her being able to reproduce. Alas, it has never been my personal experience that linguistic ability provides a crucial advantage in the competition for sexual partners, and I do not find myself convinced in any great measure by this application of the currently fashionable evolutionary approach to exploring the nature of the human mind. Then come three chapters arguing against the existence of a critical period. James Flege provides research evidence to show that level of achievement in pronunciation is closely related to age of first exposure to the second language. He claims that, even for children, the later in life the first exposure to L2, the greater the degree of foreign accent, with no sudden discontinuity in the figures at a certain age to suggest that a critical [-3-] period has ended, a window of opportunity suddenly closed. Other hypotheses, he claims, can be advanced to explain the linear nature of the relationship between age of first exposure and L2 pronunciation, notably that pronunciation of L2 varies as a function of how well one pronounces L1. Theo Bongaerts takes a very different approach in his paper, which again focusses on pronunciation; his view is that people who begin learning L2 later in life can sometimes achieve native-like pronunciation. If such learners do indeed exist, and Bongaerts presents evidence to suggest that they do, then there can be no biological window of learning opportunity that closes at a fixed age; instead, there must be other explanations for the lack of success of the majority of learners. These two papers, then, while arriving at the same conclusion with regard to the existence of an L2 critical period, do so on the basis of more or less contradictory evidence! Finally, Bialystok and Hakuta, focussing primarily on syntax rather than pronunciation, again point to the lack of any age-related discontinuity in the nature of L2 acquisition. They also suggest that belief in a critical period may be the result of

misattribution of causality in examining the evidence; even the neurological differences pointed out by Weber-Fox and Neville could be the result of differences in the learning experience, rather than causes of such differences. This is all somewhat confusing, and the only conclusion that a reader can come to at the end of the book is that there are no easy answers on the CPH. What is clear is that the old notion that the nature of L2 acquisition changes suddenly and dramatically at around the age of 12-13 because of changes in the brain is much too simplistic (as has been generally recognised for some time). If there is any truth in the CPH, then there may be different critical periods for different language skills, different types of change at different ages. If on the other hand there is no physical change in the brain which can be directly related to language learning, other powerful explanations are needed to account for the dramatic decline in ultimate achievement generally seen in later second language learners compared to young children -- and such explanations are no more than tentative guesses at present. None of this is of much immediate help to the practising language teacher; it may even be in the long run that exact age of first L2 exposure and the CPH will not turn out to be such a central issue after all, at least not in a formal learning context. But whether it is itself a key field, or whether it simply takes us into other areas which are key fields, further research into the relationship between age and language learning is likely to help us delve deeper into the mysteries of the mechanisms of second language acquisition. Birdsong's collection of papers describes a waystage--or rather

Second Language Acquisition and the Critical Period Hypothesis Birdsong, David (Ed.) (1999) Mahwah, NJ: Lawrence Erlbaum Associates Pp x + 191 ISBN 0-8058-3084-7 (cloth) US $45.00 (special prepaid price, US $19.95) Is there a single key issue in the field of second language acquisition/learning, an as yet unresolved matter on which all else depends? A good case could be made for the question of whether or not there is a critical period for second language learning being just such a key issue. In other words, does the nature of second language acquisition change if the first exposure to the new language comes after a certain age? This question is closely linked to the question of whether first language (L1) acquisition and second language (L2) acquisition are essentially the same process, or very similar processes, and if so whether this is the case for some learners, or for all. In practical terms, it could be central not only to such issues as the optimal age at which children should start learning foreign languages, but also to the best teaching/learning approach for adults. Krashen's Input Hypothesis (Krashen, 1985) is totally undermined if a critical period does indeed exist, since the hypothesis assumes not only that L2 acquisition is similar in nature to L1 acquisition, but also that this is the case for learners of any age. Alhough many would claim that Krashen's theories are seriously flawed in any case, their influence in the field of second language teaching can hardly be denied. Issues such as the relative importance of lexis

and syntax in teaching materials must ultimately link back to the way in which second language knowledge is organised in the brain. If that organisation is different in learners who have first been exposed to L2 after a certain age, then this has a bearing on choice of teaching approach. Yes, I believe there is a strong prima facie case for regarding the debate over the Critical Period Hypothesis (CPH) as a central issue. The concept of a critical period is well known in nature. One example is imprinting in ducks and geese, where it is claimed that ducklings and goslings can be induced to adopt chickens, people, or even mechanical objects as their mothers if they encounter them within a certain short period after hatching. (Note, however, that the exact nature of even this apparently well-documented instance of a critical period is now coming under fire; see Hoffmann, 1996). In humans, on the basis of extant evidence, it seems that there is a critical period for first language acquisition; those unfortunate persons who are not exposed to any language before puberty seem unable to properly acquire the syntax of their first language later in life. (Inevitably, our knowledge in this area is sketchy and unreliable, being based solely on a very few cases, of which that of "Genie" is the most celebrated and best known; see Eubank and Gregg's article in Birdsong for a discussion.) [-1-] Provided that a person learns a first language in the normal way, the question is then whether there is a certain biologically-determined critical period during which that person can acquire further languages using one mental mechanism, probably resulting in a high level of achievement if learning continues, and after which the learning process for new languages changes, so that the learning outcome will not be as good. Note that we are not talking here about the commonlyobserved and widely-accepted generalisation that learning gets harder as one gets older; nor is the question one of whether changes in attitudes or situation alter the learning process as one gets older. The issue is whether a fundamental change in the learning process and thus in potential learning outcomes related to second languages occurs in the brain at a fairly fixed age, closing a biological "window of opportunity" (although as Birdsong points out in his introduction to this book, there is no single formulation of the Critical Period Hypothesis, but a number of different versions of the theory). This book contributes to the debate by juxtaposing a number of papers which consider the CPH from a variety of points of view, and which arrive at a variety of conclusions. Most of the papers in the book are based on talks given at an AILA symposium on the CPH which took place in Finland in 1996. It must have been quite a conference; the names of the contributors to this book make up a Who's Who of researchers in fields related to the CPH issue, and the diversity of the opinions held by the contributors must have made for some sharp exchanges. The book contains research papers by both proponents and opponents of a CPH for SLA, thus drawing the reader into the controversy. What you get in the book is what you might expect from the above description. First, it must be said that it is a fairly tough read. Some of the writers are easier to follow than others, but these are research papers, and anyone unfamiliar with the fields covered--and there is a considerable range of fields--is likely to have to work quite hard at some of the texts at least. Second, there is no overall conclusion, even though the editor does have his own clearly-expressed view. This is not because of differences in the interpretation of data; it is because the various writers operate in

different areas of research, each casting a different light on the central issue. These varied areas of research produce conclusions which point in different directions, and because of the lack of common ground on which to debate, the differences cannot easily be resolved. Third, there is an unevenness about the book. Some writers report on tentative conclusions from ongoing research; others simply reproduce material on completed projects which can be found in almost identical form elsewhere. The relevance of the research presented to the central issue also varies. These points might be regarded as drawbacks. But the compensation comes in having so much relevant and fairly up-to-date material on the issue collected together in one volume, providing insights into current knowledge and thinking from a variety of angles. In his introduction, Birdsong briefly surveys the background to the debate, outlining some of the arguments previously advanced for and against the existence of a critical period. He is particularly well suited to this task, having "changed sides" on the issue in the early 1990s. After the background section, Birdsong goes on to present a careful summary of each of the chapters in the book. While admitting his adherence to the "anti-CPH" camp, he makes no attempt to resolve the evidence presented in the various chapters, and concludes that in total the contributions to the book demonstrate "the richness, depth and breadth of the critical period enquiry" and that they "testify to the unmistakable centrality of the CPH in L2A research" (p. 18). The introduction is clearly written, and since it contains so much summarising material it can stand as a valuable survey of the field in itself. However, some of the chapters in the book do not lend themselves to brief summaries (the chapter by Eubank and Gregg, for example, is far too broad in scope) and thus reading the introduction is no substitute for reading the entire book. [-2-] There are three chapters providing evidence for the existence of an SLA critical period. First, Weber-Fox and Neville take a frontal approach to the issue with an investigation of neural activity while performing L2 tasks in subjects whose first exposure to L2 was at different ages. Their paper has the rather daunting title of "Functional Neural Subsystems Are Differentially Affected by Delays in Second Language Immersion: ERP and Behavioural Evidence in Bilinguals." The findings do not point to the existence of a single critical period; the patterns of change vary for different language tasks. The authors claim, fairly circumspectly, that "our findings are consistent with the hypothesis that the development of at least some neural subsystems for language processing is constrained by maturational changes, even in early childhood. Additionally, our results are compatible, at least in part, with aspects of Lenneberg's . . . original hypothesis that puberty may mark a significant point in language learning capacity and neural reorganization capabilities" (pp. 35-36). Eubank and Gregg, in a wide-ranging paper entitled "Critical Periods and (Second) Language Acquisition: Divide et Impera," recognise the importance of neurological investigation in their consideration of whether second language learners retain access to Universal Grammar, and find Weber-Fox and Neville's line of research a promising one. Sandwiched between these two chapters comes a paper by Hurford and Kirby which takes a very different approach to the problem. The writers' argument is an evolutionary one; they produce computer models to suggest that a critical period for language acquisition finishing at puberty inevitably evolves in order to produce maximum language learning by the time a reproductive age is reached. However, their argument appears predicated on the assumption that the level of an individual's language knowledge governs the likelihood of his or her being able to reproduce. Alas, it has never been my personal experience that linguistic ability provides a crucial advantage in the competition for sexual partners, and I do not find myself

convinced in any great measure by this application of the currently fashionable evolutionary approach to exploring the nature of the human mind. Then come three chapters arguing against the existence of a critical period. James Flege provides research evidence to show that level of achievement in pronunciation is closely related to age of first exposure to the second language. He claims that, even for children, the later in life the first exposure to L2, the greater the degree of foreign accent, with no sudden discontinuity in the figures at a certain age to suggest that a critical [-3-] period has ended, a window of opportunity suddenly closed. Other hypotheses, he claims, can be advanced to explain the linear nature of the relationship between age of first exposure and L2 pronunciation, notably that pronunciation of L2 varies as a function of how well one pronounces L1. Theo Bongaerts takes a very different approach in his paper, which again focusses on pronunciation; his view is that people who begin learning L2 later in life can sometimes achieve native-like pronunciation. If such learners do indeed exist, and Bongaerts presents evidence to suggest that they do, then there can be no biological window of learning opportunity that closes at a fixed age; instead, there must be other explanations for the lack of success of the majority of learners. These two papers, then, while arriving at the same conclusion with regard to the existence of an L2 critical period, do so on the basis of more or less contradictory evidence! Finally, Bialystok and Hakuta, focussing primarily on syntax rather than pronunciation, again point to the lack of any age-related discontinuity in the nature of L2 acquisition. They also suggest that belief in a critical period may be the result of misattribution of causality in examining the evidence; even the neurological differences pointed out by Weber-Fox and Neville could be the result of differences in the learning experience, rather than causes of such differences. This is all somewhat confusing, and the only conclusion that a reader can come to at the end of the book is that there are no easy answers on the CPH. What is clear is that the old notion that the nature of L2 acquisition changes suddenly and dramatically at around the age of 12-13 because of changes in the brain is much too simplistic (as has been generally recognised for some time). If there is any truth in the CPH, then there may be different critical periods for different language skills, different types of change at different ages. If on the other hand there is no physical change in the brain which can be directly related to language learning, other powerful explanations are needed to account for the dramatic decline in ultimate achievement generally seen in later second language learners compared to young children -- and such explanations are no more than tentative guesses at present. None of this is of much immediate help to the practising language teacher; it may even be in the long run that exact age of first L2 exposure and the CPH will not turn out to be such a central issue after all, at least not in a formal learning context. But whether it is itself a key field, or whether it simply takes us into other areas which are key fields, further research into the relationship between age and language learning is likely to help us delve deeper into the mysteries of the mechanisms of second language acquisition. Birdsong's collection of papers describes a waystage--or rather This article is about a critical period in an organism's development. See also America's Critical Period.

In general, a critical period is a limited time in which an event can occur, usually to result in some kind of transformation. A "critical period" in developmental psychology and developmental biology is a time in the early stages of an organism's life during which it displays a heightened sensitivity to certain environmental stimuli, and develops in particular ways due to experiences at this time. If the organism does not receive the appropriate stimulus during this "critical period", it may be difficult, ultimately less successful, or even impossible, to develop some functions later in life.[1] For example, the critical period for the development of a human child's binocular vision is thought to be between one and three years,[1] and further critical periods have been identified for the development of hearing and the vestibular system.[2] There are critical periods in childhood in which imprinting can occur, such as when a greylag goose becomes attached to a parent figure within the first 36 hours after hatching. A young chaffinch must hear an adult singing before it sexually matures, or it will never properly learn the highly intricate song.[3] These observations have led some to hypothesise a critical period for certain areas of human learning, particularly language acquisition. Experimental research into critical periods has involved depriving animals of stimuli at different stages of development. Other studies have looked at children deprived of certain experiences due to illness (such as temporary blindness), or social isolation (such as feral children). Many of the studies investigating a critical period for language acquisition have focused on deaf children of hearing parents.

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1 Linguistics o 1.1 First language acquisition o 1.2 Second language acquisition 2 See also 3 External links

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4 References

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The critical period hypothesis (CPH) refers to a long-standing debate in linguistics and language acquisition over the extent to which the ability to acquire language is biologically linked to age. The hypothesis claims that there is an ideal 'window' of time to acquire language in a linguistically rich environment, after which this is no longer possible due to changes in the brain. The hypothesis has been discussed in the context of both first (FLA) and second language acquisition (SLA), and is particularly controversial in the latter. In FLA, it seeks to explain the apparent absence of language in individuals whose childhood exposure was very limited, and in SLA it is often invoked to explain variation in adults' performance in learning a second language,

which is very often observed to fall short of nativelike attainment. Various ages have been proposed for the supposed end of the CPH; those that point to pre-adolescent ages such as 12 have been vulnerable to alternative theories which invoke psychological or social factors applying as children move into adolescence.

Contents [hide]

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1 History 2 First language acquisition o 2.1 Children without language 3 Footnotes

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4 See also

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History The critical period hypothesis is associated with Wilder Penfield, whose 1956 Vanuxem lectures at Princeton University formed the basis of his 1959 work with Lamar Roberts, Speech and Brain Mechanisms. Penfield and Roberts explored the neuroscience of language, concluding that it was dominant in the left hemisphere of the brain on the basis of hundreds of case studies spanning many decades. The review focussed on how individuals with brain damage evidenced atypical linguistic performance, rather than examining neurotypical cases of 'normal' language acquisition, and the authors' conclusions were also based on the prevailing tabula rasa view that children were born without any real innate language ability; however, linguistic "units", once "fixed", would affect later learning.[1] Their recommendations for language schooling recommended starting early in order to avoid fixed effects; though these claims did not form the core of the book, being confined to the last chapter, other researchers and popular opinion were much-influenced by them. The hypothesis was developed by Eric Lenneberg in his 1967 Biological Foundations of Language, which set the end of the critical period for native language acquisition at 12. The hypothesis has been fiercely debated since then, and has continued to inform popular assumptions about the presumed (in)ability of adults to fluently learn a second language. In SLA, a weaker version of the CPH emerged in the 1970s. This refers to a sensitive period in which nativelike performance is unlikely but not ruled out.[2] The strongest evidence for the CPH is in the study of accent, where most older learners seem not to reach a native-like level. This leads some researchers to apply the CPH only to second language phonology rather than all aspects of language; indeed, a CPH was not seriously considered for syntax until the 1990s, in research that remains a minority view.[3] However, under certain conditions, native-like accent has been observed, suggesting that accent in SLA is affected by multiple factors, such as identity and motivation, rather than a biological constraint.[4]

First language acquisition

For more information, see: First language acquisition

Children without language The CPH as applied to first language acquisition proposes that a child deprived of exposure to natural language would fail to acquire it if exposure commenced only after the end of the critical period. Because testing such a theory would be unethical, in that it would involve isolating a child from the rest of the world for several years, researchers have gathered evidence of the CPH from a few victims of child abuse. The most famous example is the case of Genie (a pseudonym), who was deprived of language until the age of 13. Over the following years of rehabilitation, improvement in her ability to communicate was noted, but during this time she did not develop the language ability common to other children.[5] However, this case has been criticised as a firm example of the critical period in action, and data has not been gathered from Genie since the 1970s.[6] Although there are several cases on record of deaf children being deprived of sign language, this could also count as abuse. One case in which no abuse took place is that of Chelsea, whose deafness was left undiagnosed until the age of 31. Once hearing aids had apparently restored her hearing to near-normal levels, she seemed to develop a large vocabulary while her phonology and syntax remained at a very low level.[7] The implications of this have been disputed, given the apparently unlikely circumstances of Chelsea's diagnosis.[8]

Footnotes 1. ↑ Penfield & Roberts (1959: 252; Dechert 1995: 67-94). 2. ↑ Oyama (1976). 3. ↑ Scovel (1969) links the CPH mainly to 'foreign accent'; DeKeyser (2003) argues for a critical 4. 5. 6. 7. 8.

period in syntax, but only for 'implicit' (subsconscious) learning. ↑ Moyer (1999); Bongaerts et al. (1995); Young-Scholten (2002). ↑ Curtiss (1977). ↑ Jones (1995). ↑ Pinker (1994). ↑ Bialystok & Hakuta (1994).

1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages 0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis.

Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition.

There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the

confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a

critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing

finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary

grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the

Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good.

Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this

hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the

pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact

that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such

complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages.

Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück

Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages 0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the

ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia

In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3

The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive

constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was

deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the

late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the

way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the

complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers.

2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7

show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be

due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English.

8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek

Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages 0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious.

Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport.

These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows.

3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical

period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere.

The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages.

Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis

assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not

generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small

vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they

7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain

preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also

evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think

that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages

0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time

period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of

deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement

decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest

that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left

hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic

word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have

learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate

this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For

example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present

feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so

much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people

form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately

leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages

0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known.

Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia.

Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain

are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to.

When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period.

But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12).

The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and

syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of

regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a

compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can

discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above.

But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that

second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of

the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages

0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart

music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it.

As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on

data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the

attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its

functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native

learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order

5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in

this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate

language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper.

3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin

grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made.

This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to

be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages

0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of

the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption.

In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also

have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick

language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance

was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects.

Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same

findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles,

outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin

speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity

among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent

use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean

as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the

process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages

0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which

language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences. While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in

us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and

show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea.

Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie

concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport. The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf

children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later. But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their

general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task. The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another

direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of

communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called decreolization. If the Creole language develops to completely new language this process is called hypercreolization.

Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume. But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to

fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages.

Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should

always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. 1 Klaus Tichacek Mat. Nr.: Applied NLP Universität Osnabrück Wintersemester 2002 / 2003

The “Critical Period Hypothesis” and Pidgin and Creole languages

0.Introduction In this paper I outline the course and content of our referat on the critical period hypothesis. Then I am going to relate the critical period hypothesis to the existence of pidgin and Creole languages. I think that pidgin and creoles provide direct evidence for the critical period hypothesis and that they can be explained on the basis of the critical period hypothesis. The critical period hypothesis seems to be the reason for the striking differences of pidgins and creoles. The fact that creoles are developed by children who are obviously still in their

critical period is a clear evidence for the hypothesis. But let’s start by presenting the critical period hypothesis. 1.The critical period hypothesis The critical period hypothesis states that there exists a certain time window during which language learning must occur. The idea of a critical period is fairly old and well known. For example there is a critical period in learning to really master some music instrument, especially the violin and the piano. If one starts too late the complex and fast movements of the fingers will not be learned as good as by early starters. Already at the time of Mozart music education started in early childhood because this critical period was known. Another commonly known fact is that the general cognitive abilities decay with age. Old people find many memory tasks more difficult than young people. This is also reflected in current IQ-Test where the peak of the scale is approximately between 20 and 35. In this time period you have to score higher than all other age groups to get the same IQvalue. The common knowledge of effects like these makes the assumption the there is also a critical period for language acquisition obvious. Since ages there has been an enormous interest in this question. It is said that already the ancient Egyptian king Psammetichus conducted the ultimate languagelearning experiment. He placed two infants in an isolated cabin and allowed nobody to speak to them. Two years later the children spoke Phyrigian, so the story goes. Plausibility of this tale may be doubted but it clearly shows the general interest in the question about a critical period for languageacquisition. There are also numerous reports of people who grow up under inhumane conditions and did not develop language, a famous German example is “Kaspar Hauser” who clearly astonished the scientist at his time. 2 This enormous interest in the question about a critical period for languageacquisition has lead to an extensive research in this area of linguistics and it is still a hotly debated question in the area of cognitive sciences.

While the general notion that there exist this critical period for languageacquisition is now an accepted fact it is still unclear what exactly causes it. That there are some internal changes in us seems to be obvious but exactly what happens remains unknown. It is mostly assumed that there are some maturational constrains on the development of the brain that cause the critical period. Future research and fMRI studies might further justify this assumption. In our referat we gave a rather classical report on the critical period hypothesis and the found evidence for it. As indirect evidence we presented the classical studies by E. Lenneberg (1967) on aphasia. Lenneberg provided a first argument for the existence of a critical period in language acquisition. As a second evidence and critical test for the hypothesis we presented some rare cases of deprived children who were “real” late learners. One of the most famous cases of this kind is Genie, a “modern day wild child” which we discussed in more detail. As a third and final evidence we presented controlled studies on ASL signers and second language learners by E. Newport. These evidences are now shortly recaptured 1.1 Age and recovery from traumatic aphasia In his book “´Biological foundations of language” E. Lenneberg (1969) introduces the notion of a critical period for language acquisition in humans. The book summarizes and investigates several findings from clinical investigations on brain injuries and recovery patterns. Another aspect Lenneberg considers is the age of lateralization of speech function and the confinement of certain brain functions from one hemisphere to the other after hemispherecomy (the complete removal of an entire hemisphere). A very general and important discovery of Lenneberg is that the recovery patterns from aphasia are very different in adults and in children. On the one hand adults have a time window of three to five months during which they may recover from aphasia but after this

period all remaining symptoms are irreversible. And adult show no sign of relearning their language. On the other hand children between the ages of four to ten recover fully from aphasia and show no time window during which recovery must take place. Infants even start to relearn their language totally from the beginning. But with increasing age the recovery pattern of children quickly becomes the same as for adults. After the middle teens children may also have irreversible symptoms. But recovery patterns from aphasia are not the only evidence Lenneberg presents. Based on data by Basser (1962) Lenneberg makes the claim that both hemispheres of the human brain are epipotential during a period in infancy. At the beginning of language development both hemispheres are involved in language learning. Only after a certain while this involvement decreases and the left hemisphere becomes the major bearer of language functions. But during this epipotential period the right hemisphere is also able to take on speech and language functions as the data of children of various ages with lesions or hemispherecotmy of one hemisphere shows. 3 The raw data Lenneberg used to draw his conclusions was rather incomplete and several terms were used inconsistently and different by his various sources. But the book remains nevertheless convincing. But it may only contribute indirect evidence for the critical period hypothesis. The main thing which the studies presented in this book can show is that there is a critical period for the contralateral hemisphere to take over the functions of the damaged hemisphere. 1.2 “Wild children” – evidence from rare cases The best evidence for the existence of a critical period would be of course an experiment like the Egyptian king Psammetichus conducted. But luckily this is not possible due to moral conventions of the society. Unfortunately there are sometimes cases where children were

deprived from linguistic input for various reasons. Theses cases are then particulary interesting for linguistic research. We presented three cases of such cases, Isabelle, Genie and Chelsea. Isabelle was raised by a speechless mother and had not learned any language when she was found at the age of six. Within only one year Isabelle learned to speak at the level of her 7 year old peers. As Isabelle was still within the time window of the critical period her quick language acquisition is exactly what was expected by the hypothesis. The second child, Genie, was found at the age of 13. Genie was kept by her parents in the attic and beaten constantly. She grew up totally isolated in her room and was never spoken to. When she was found there were great attempts to teach her language. Genie made great process but never managed to acquire normal language abilities. Her development suggest that there are some aspects of language which can be learned after the critical period but also some which must be learned during the critical period. One of the things Genie mastered was the basic word order. This seems to be a feature which still can be learned after the critical period. But Genie performed only very poorly on proforms, movement rules, passive constructions, noun verb agreements, auxiliary structures and reflexives. She also never used functional category words. The study of Genies development is also particular interesting as one can compare her use of language with the grammatical structure of so called pidgin languages. The most astonishing finding is that pidgin languages typically lack the same structures as Genie does. I will discuss this topic later in more detail. Besides from the fact that Genie did not develop normal language abilities she was also abnormally slow at language learning. This might suggest that she could be retarded or have some serious damages from her childhood. But this was not the case, on the contrary in tests which rely entirely on the right hemisphere Genie scored higher than normally intelligent

persons. This suggest that Genie most of the time uses her fight hemisphere to solve cognitive task and also for language processing. S. Curtiss who did most of the studies with Genie concluded that “ the cortical tissue normally committed to language and related abilities my functionally atrophy” if language is not acquired at the appropriate time. This idea is also in accordance with the findings of Lenneberg. He had records of patients who confined language to the right hemisphere after hemispherectomy. Their performance was comparable to Genie’s. This strongly suggests that Genie’s left hemisphere lost its functional abilities as it was never triggered to perform these functions during the critical period. But this also changes the view on the critical period. Now we should see the critical period not as a period for language acquisition but as a period for functional development of the left hemisphere. The left hemisphere seems to be more specialized for language learning and 4 some other tasks while the right hemisphere seems to be more flexible in taking on various tasks but performs them not as good as the left hemisphere. The third and last case we discussed was a woman, Chelsea, at the age of 31. Chelsea was deaf but mistakenly diagnosed by doctors as retarded. When her deafness was recognized at the age of 31 she had not learned any language. She acquired a sizeable vocabulary and produced multiword utterances but her sentences do not even have the rudimentary grammatical structure of Genie’ s. As Chelsea was already way beyond the critical period this was exactly what the hypothesis would predict. These three cases of late language learners give strong evidence for the existence of a critical period hypothesis and also provide some insight in the internal mechanisms of language acquisition. 1.3 Controlled studies In the last part of our referat we presented some controlled studies on language acquisition conducted by E. Newport.

The first series of studies was performed on deaf children who provide a unique opportunity to study the differences in language acquisition at different ages. Only a small part of all deaf children are born to deaf parents and exposed to ASL, a natural language, from birth. There is a wide variation for the age of ASL acquisition in the deaf community. These experiments can therefore provide direct evidence for the critical period as they are done under controlled conditions with a rather homogenous group of subjects. Newport formed three major groups of subjects in her experiments. She distinguished native learners who were exposed to ASL from birth, early learners (first exposure around age 4 – 6) and late learners (first exposure after the age of 12). The data of the experiments shows that the late learners performed significantly worse than the early learners. Moreover it was shown again that some properties of language like basic word order are not affected by the age of the first exposure while others are. This is exactly what was also found in Genie’ s language abilities. The late learners did not master the same structures as Genie. Later I will discuss this topic further as this can also be observed in the creation of Pidgin languages. Some tasks on morphology give strong evidence for a steeply declining performance of the late language learners. Also the typical types of errors performed by the groups of learners were very different. The late learners showed a highly variable use of ASL including inconsistencies in individual responses. Again this is some feature which also is present in the Pidgin languages. Newport’ s second experiment focused on second language learning. The phenomenon of a declining performance with increasing age was also found in second language learning. The subjects were native Chinese or Korean speakers who learned English as a second language. Again groups in dependence of the age were formed as age is the interesting variable here. The results show that in general subjects who started learning English earlier performed better than those who started later.

But this does not mean that older people generally can’ t learn a second language. There were also some good late learners among the subjects but their performance is possible due to their general great cognitive performance. The group of early learners performed more homogenously and they also showed a strong correlation between age of acquisition start and performance. An inspection of the performed error patterns in the older subjects showed again the same findings as the ASL study and the research on Genie. The older learner’ s mastered word order 5 and the use of the morpheme -ing but virtually all other aspects of English morphology and syntax showed a rather inconsistent and highly variable use. Also a striking feature of the language of the late learners was that they used “ frozen” structures which they seemed to have learned as whole and did not analyze their internal structure. The young learners on the other hand showed mainly componential errors and selective omission of some morphemes. This interesting phenomenon lead Newport to the “ Less is more hypothesis” . This hypothesis assumes that the reason for the differences between adult and child language learners is the way in which children perceive and store the linguistic input. The general idea behind this hypothesis is that componential analysis is required in language learning and that children are better in this because cognitive abilities of adult are too good. Children seem to be a privileged language learner as they are the less informed learner. Their smaller “width” of short term memory might be the reason why the task of mapping meaning to single morphemes is easier for children as they perceive only smaller parts of the complex input. Adult learners are able to store larger chunks of the complex input and therefore have to do the mapping on the whole complex expression which is a computationally very demanding task.

The presented experiments strongly imply that language learning depends upon the age of the learner. There seems to be a biologically defined critical period hypothesis. I will now consider the creation pidgin and Creole languages which seem to provide another direct evidence for the critical period hypothesis. 2.0 Comparison of the CPH and Pidgin and Creole languages In the following I’m going to relate our referat and the critical period hypothesis to the first referat on pidgins and creoles. The referat on pidgin and Creole languages introduced the general idea of pidgins and creoles, outlined their specific features, presented a paper by D. Bickerton and showed a study done in this area as well as the “ Language Bioprogram Hypothesis” by Mufwene. The study was again performed by E. Newport. Together with C. Hudson the phenomenon of regularization in Creole languages was examined. The main question behind this study was to find out whether adults are responsible for this process and able to learn rules. To investigate this issue adult subjects were exposed to an pidgin like language and later tested on their comprehension and production ability of this language. The actual finding of this study was that that adults are able to learn rules when they are exposed to variable input but they do not generate rules. The only rules adults would develop are rules which would further reduce the complexity of the language. The “ Language Bioprogram Hypothesis” by Mufene was only outlined shortly as the time during the talk was already over. The group mainly presented criticism against this hypothesis. In the following I will concentrate on the general features of pidgin languages outlined by the group. These general features allow a very good explanation for the existence of pidgin and Creole languages on the basis of the critical period hypothesis and with such an explanation the pidgin and Creole languages can be seen as further evidence for the critical period hypothesis. 6 2.1 Pidgin languages

A pidgin language is a language which is based on another language or to be precise on several other languages. A pidgin language develops among people and becomes a means of communication among people who speak different native languages. But in contrast to normal natural languages a pidgin language shows only a very poor grammar and a sharply curtailed vocabulary. The mayor ingredients of a pidgin language come from the native languages of the pidgin speakers. The language with the strongest influence on the pidgin is called the superstrate language and all other contributing languages are called the substrate languages. The vocabulary is mainly drawn from the superstrate language whereas the grammar is a compound product of all involved languages. Slavery and colonization were a major force for the formation of pidgin languages. For example the slaves brought to America did not necessarily speak the same language but had to communicate with each other. To accomplish this they invented a pidgin language with English as superstrate language. What is typical for pidgin languages is that their use is highly variable and due to the small vocabulary many concepts are expressed in whole sentences. By its definition a pidgin language is native to none of its speakers. 2.2 Creole languages When a pidgin is used in a community and the next generation learns this pidgin as a native language a process called creolization begins. This is done by the children who receive the pidgin language as their only input and basis for language acquisition. Here a remarkable thing happens, the children do not learn this easy and poor language but they tremendously extend it and transform it into a real natural language with full complexity and a uniform use among its speakers. This newly developed language has a complex grammar and an extended vocabulary. When this Creole adopts more and more features of the superstrate language it becomes a variety of the standard of this superstrate language, this process is called

decreolization. If the Creole language develops to completely new language this process is called hypercreolization. Linguists have noted similarities in grammatical structure among all Creole languages around the world. This is remarkable as most of these languages developed totally independent of each other with little or no contact at all. This feature of Creole languages suggests that there are biological reasons for this similarity among these languages. Maybe the same biological reasons which account for the critical period hypothesis? I will discuss this idea in the later part of this paper. 3.0 The critical period hypothesis and Pidgin and Creole languages The form and structure of pidgin languages are very simple. Upon further analysis one can discover that their grammar und usage resembles very much the language used by Genie or Chelsea and that the errors performed by late language learners also seem to be a present feature of pidgin languages. Pidgin languages are generally learned by adults therefore. It is no big surprise that the adults who “ invent” the pidgin invent it by incorporating the errors that late first and second language learners usually make. Also a striking feature of the pidgin languages is that they 7 show a highly variable use of grammar, exactly what has been found in the error patterns of late learners in the studies by Newport (1990) presented by us. This suggests that the poor grammatical structure of Pidgin languages is mainly due to the fact that the “ learners” of the pidgin are adults who are beyond their critical period for language acquisition. In this sense a pidgin has a very high similarity to a learned second language spoken by some poorly performing adult. If you encounter a German in France who learned French very poorly and late in life the structure of his sentences should resemble a Pidgin with French as superstrate and German as substrate language, as much French vocabulary as possible but used with a rather German grammar. At least this is what I would assume.

But when children learn the pidgin language as their native language they start to change it. On the basis of the critical period hypothesis this occurs because the children are still able to fully grasp the complexity of a natural language. The start the process of creolization and learn a complex Creole language with an uniform grammar across its speakers. This is also what was found out by Newport (1990), early learners showed a highly consistent use of their grammar and rather made componential and omission errors. This similarity suggests that children are solely responsible for this regularization process of the pidgin grammar. This idea is also further supported by the findings of Newport and Hudson mentioned above. But the “Less is more Hypothesis” , an explanation for the CPH also presented by Newport, does not account for the fact that the children extend the grammar of the pidgin language so much. It seems that there is more about the critical period hypothesis than just a plain computational advantage for the uninformed learner about the critical period hypothesis. Somehow it seems that the internal constraints on language acquisition have a certain preference for a grammar with the complexity of natural language grammars. This might be due to some internal “ bio program” as proposed by Mufwene but I prefer the classic idea of a universal grammar proposed by Chomsky. I cannot explain how children come to invent such complex grammatical features on their own without having any input as basis. But nevertheless the finding that all Creole languages around the world have similarities in their grammatical structure strongly suggests that an internal mechanism, program or constraint is present which drives our language development. And this internal structure is only active during the critical period as Creole languages are only developed by them. Adults can only produce the simple Pidgins. And this has nothing to do with learning a first or a second language. Chelsea and Genie

learned English as their first language and nevertheless showed the structural deficits also found for Pidgin languages. Also the experiments on second language learners conducted by Newport (1990) show that they late learners performed the same error patterns although they had different native languages. The experiment was actually only done on subjects with either Chinese or Korean as native language but as the same error patterns were also found for late ASL learners I think that the generalization to all second language learners with different native languages can be made. This contradicts the so called “ Fundamental difference hypothesis” which suggests that second language learning is based on the native language. To some extend this might be true, especially if the first and the second language are very similar. But the finding that people form different language backgrounds perform the same errors in second language learning strongly suggests that these errors are due to something internal to all humans that does not correlate strongly with the native language of the speaker. Chelsea and Genie are also evidence for this as they performed the same errors and showed the same deficits without having a native language before their acquisition of English. 8 I think that these findings pretty much explain the structure of Pidgin languages. Also the process of creolization is well explained by this, the children are simply still in their critical period and therefore able to capture the complex structures. As Isabelle showed this can happen very quickly without any effort on the side of the children what suggest that this is a natural process. 4.0 Conclusion As I have outlined above the critical period hypothesis is at least partially able to explain the existence and structure of Pidgin and Creole languages. These two phenomenons, the invention of Pidgins and their evolution to Creoles, are exactly what one would expect if the

critical period hypothesis is correct. Therefore these two topics of language acquisition are very strongly related and should always be considered together if features them are examined. It cannot be by pure accident that adults are worse at language learning and that Pidgins are produced or “ invented” by adults. And it is also not an accident that children who learn a language that easily start the process of creolization. I think that the connection of these two topics is obvious and should be examined in the future. A hypothesis for language acquisition which includes these two approaches is likely to be more biologically plausible than the presented “ Less is more hypothesis” or any other of the mentioned hypothesises. I therefore conclude that the critical period seems to be a feature of humans which ultimately leads to Pidgin creation and Creole creation. By this mechanism nature manages to produce an elaborate language system with complex grammatical features which might need to evolve over some generations but is finally a much regularized system with clear cut rules. I think that this can be followed from the evidence for the critical period hypothesis and from the facts about Pidgin and Creole languages. Gina La Porta Literature Review Professor Han A&HL 4087 Section 1 Due Date: May 8, 2000

A Critical Look at the Critical Period Hypothesis Introduction The purpose of this paper is to investigate the evidence of the Critical Period Hypothesis (Lenneberg 1967). Questions posed throughout this paper are: “Is there a critical period for learning a second language?” If so, “At what age does a decline in learning a language

commence?” And finally, “What are the implications of these theories for second language teaching?” Articles written by Bialystok (1997), Johnson and Newport (1989), Long (1990), and Patkowsky (1980), are reviewed and commented upon in this paper.

Review of Material Many researchers hold opposing beliefs about the Critical Period Hypothesis put forth by Lenneberg (1967). The hypothesis cited in Lightbown and Spada (1999) states that there is a “specific and limited time period for language acquisition”

(p. 19). Lenneberg believed that

the “language acquisition device, like other biological functions, works successfully only when it is stimulated at the right time” (p. 19). But what does further research suggest? Patkowsky (1980) suggests that a critical period for second language learning does indeed exist. His study meant to find out about the likelihood of a critical period for learning a second language. Patkowsky found that learners under the age of fifteen achieved higher syntactic proficiency than those who were over the age of fifteen at the onset of exposure. Patkowsky’s study included 67 highly educated immigrants a.) from various backgrounds b.) from various ages c.) who lived in the United States for various numbers of years, and d.) who had all lived in the United States for at least five years. Patkowsky used a control group of 15 native-born Americans. Judges employed a rating scale of 0 to 5. Five served as the most native–like level and 0 indicated almost no English capability. Judges rated written transcripts of tape-recorded interviews. The study sought to discern if learners who were exposed to second language learning before the age of 15 actually received higher syntactic proficiency than older learners. The results showed that of those who were exposed to English pre-puberty (participants up to the age of fifteen), all, (except one) achieved ratings of four through five whereas those in the postpuberty group received a wider range of scores, with the mean falling in the three range. “Thus, even at a purely descriptive level, the distributional characteristics of the two nonnative groups are clearly consonant with the notion of a sensitive period for the acquisition of syntax in a second language” (p. 454).

This study was a departure from earlier studies since the most obvious measure of proficiency had previously been in the linguistic domain of phonology. Patkowsky posited that among all the factors he examined in his study, age was the factor that had the most significant impact of success in learning a second language. His findings are fully consistent with the Critical Period Hypothesis. In their discussion of critical period effects in learning a second language, Johnson and Newport (1989) concede that there does indeed exist a critical period for second language learning. Johnson and Newport believe that after the age of six, the ability to learn a second language begins to decline. Johnson and Newport’s study involved 46 Chinese and Korean speakers learning English as a second language. Criteria included the following: a). subjects had at least five years of exposure to the language b.) they each had to have been living in the US for three years without leaving, and c.) subjects included were students and faculty at the college level. In this study, respondents were tested not only on syntax, but also on morphology, and were asked to judge the grammaticality of many sentences. Twelve rule types comprised the test, presenting a wide sampling of the English language. The results showed that “subjects who began acquiring English in the United States at an earlier age obtained higher scores on the test that those that began later” (p. 77). The results also show a correlation between the age of acquisition and the variance in the ultimate performance in adults. For example, they assert that there are few differences in the ultimate ability to learn language in learners before age 15. Adults, however, attain various levels of achievement. “While early learners are uniformly successful in acquiring their language to a high degree of proficiency, later learners show much greater individual variation” (p. 97). In further discussion of this proposed idea, they delineated between the alternate versions of the hypothesis. In the exercise hypothesis, it is believed that humans easily learn languages at an early age. As long as this capacity is exercised (at an early age), the theory proposes, a person’s ability to learn subsequent languages will always remain viable. The alternate version of the theories is known as the maturational state hypothesis. This hypothesis states that even though

humans have a capacity to learn languages early in life, they are unable to do so with the same outcome if learning a second language commences in the future. Johnson and Newport believe that their findings support the maturational state hypothesis.

Johnson and Newport’s study also lends credence to the critical period hypothesis, but not in the manner that Lenneberg had proposed: Lenneberg’s original proposal of a critical period in language acquisition seemed to predict a rectangular function in the relationship between age of acquisition and ultimate performance. That is, Lenneberg hypothesized that ‘normal’ language learning was possible between the period from infancy to puberty, with a loss of abilities after puberty (p. 95). Instead, Johnson and Newport (1989) found that “performance gradually declined from about age seven on, until adulthood” (p. 95). Thus according to Johnson and Newport’s research, the decline begins far before puberty, even before the threshold of fifteen years of age, as Patkowsky (1980) had found. In response to these and many other empirical studies, Long (1990), in his seminal paper, reviewed the second language research on age–related differences. In this paper he draws several conclusions that are relevant to this topic: 1. Both the initial rate of acquisition and the ultimate level of attainment depend in part on the age at which learning begins. 2. There are sensitive periods governing both first and second language development, during which both the acquisition of different linguistic domains is successful and after which it is incomplete. 3. The age-related loss of ability is cumulative, not a one-time event. 4. Deterioration in some individuals begins as early as six. In his review, Long spends much of his paper showing the flaws in the current research that purports that there is no age limitation on achieving native-like fluency. “Contrary to recent assertions in literature, there is growing evidence that maturational constraints are at work in second language learning, and that they are not confined to phonology” (p. 273). Long feels that the decline of linguistic ability while learning a second language is related not to cognitive abilities (as some propose) but to an age related device found to be before puberty.

Long’s review gives support to both Patkowsky and Newport and Johnson (whose papers are both discussed in his review) in terms of the focus on age: Starting after age six appears to make it impossible for many learners (and after age 12 for the remainder) to achieve native-like competence in phonology; starting later than the early teens, more precisely after age 15, seems to create the same problems in morphology and syntax. (p. 274) Whereas Long feels the empirical evidence supports the Critical Period Hypothesis, he concludes his article by giving credence to some of the other explanations that might help to explain the lack of ability in adults to achieve native-like competence in a second language. Affective, input, social, and neurological variables have all been used to discount the Critical Period Hypothesis. Long is inclined to give the most credence to neurological factors. “Incremental losses of plasticity with increasing brain maturation, possibly associated with myelination-if only by default, seems a more defensible position” (p. 280). In contrast to the above research, Bialystok (1997) wrote a paper that looks to deny the evidence supporting the notion of a critical period for language learning. According to Bialystok: It is undoubtedly the case that the descriptive statement regarding the general success of younger learners in acquiring a second language is true. However, the evidence does not provide convincing support for the claim that this advantage is the reflection of a sensitive period in learning (p. 133). Bialystok rather asserts that the “correspondence between language structures in the first and second language is the most important factor affecting acquisition” (p 116). She believes that successful language learners as adults can achieve the same success as children if they make the time and the space to learn and if they possess the motivation from which children usually benefit. Bialystok reviews research by Johnson and Newport (1989), yet questions their findings based on the following questions. Bialystok questions the subjects used, the structure of the research and the tasks they were given to complete. First, Bialystok cited a study (Bialystok and Hakuta, 1994) in response to the subjects used that reexamines the findings by Johnson and Newport. Bialystok and Hakuta reorganize the two segments of learners (those younger than 15 and those older than 15) into one group. Upon this re-examination, Bialystok asserts that the level where

language noticeably declines is around the age of 20. This would mean that puberty, or a prepuberty finding for a decline in language acquisition is incorrect. Bialystok and Hakuta concur with Johnson/Newport’s claims that the younger learners perform similarly to each other, whereas the adult learners have a greater variety in performance. Bialystok does assert, however, that the variety in adult learners abilities include those who actually outperform the younger learners. She asserts that the languages of the Chinese/Korean learners could be considered weak and non-dominant, thus allowing English to assume the role of the learners’ first, not second language, rendering many of the Johnson/Newport findings moot. Second, Bialystok negates the structures that gave the learners difficulty. She finds that the ability to detect errors in some, but not all of the structures did not vary with age. This, Bialystok feels, disproves the findings as well. Third, the method gives pause to Bialystok. She believes that the method of testing produced different results in two studies. This varied outcome, Bialystok believes, accounts for evidence that the outcomes could not be attributed to age factors. Bialystok cites a number of empirical studies by White and Genesee (1996), Birdsong (1992), Bongaerts (1995), and Juffs and Harrington (1995) which refute Patkowsky’s (1980) claims. For example, White and Genesee found that age made no difference in grammatical and phonological achievement. Likewise, Birdsong reported that some late learners were as proficient as younger learners on grammaticality tasks. Bongaerts found that late learners could achieve pronunciation levels at the same level as native speakers. Juffs and Harrington provide counter evidence to that of researchers such as Johnson/Newport and Patkowsky, by showing that some adult learners can achieve similar levels of success as younger learners. After supplying these data, Bialystok then admits that this evidence only serves as a minor segment of the total evidence on this subject. At this point Bialystok looks to the lack of adult success on outside factors other than age. Bialystok asserts that the relationship between languages is the reason for differences in attainment.

The hypothesis is that language learners will find it difficult to master a structure that was not a defining feature of the first language and relatively easy to master a structure shared across the two languages. These differences may be exacerbated for older learners, but there should be no age differences in the ability to learn structures that are shared across the two languages (p. 126).

Discussion After reviewing the literature documented in this paper, I have confirmed my previous thoughts about the Critical Period Hypothesis. I believe that there does exist a critical period for learning a second language. After the age of fifteen, there exists a regressive, diminished capability in learners to acquire a language. In certain linguistic domains, such as phonology, this may happen as early as the age of six. These findings present educators with serious implications for second language teaching. The following discussion is an attempt to answer the questions posed at the beginning of this paper. 1.) “Is there a critical period for learning a second language?” The evidence, in my opinion, seems to overwhelmingly state that there is indeed a critical period by which learning must commence in order to afford the learner with the chance to achieve native-like capabilities. It has been documented repeatedly that learners achieve better results depending on the age at which they begin to learn a second language. Even though some researchers try to attribute this phenomenon to other factors, I believe that there is an innate age-related factor. Bialystok’s proposal that interference between first and second language factors affects second language acquisition in adults, is suspect. If interference between two languages is the cause, why then does it not provide an overwhelming obstacle for sequential bilingual children, who have been seen to reach native-like proficiency in both languages? Also, Bialystok interprets Newport and Johnson’s (1989) study showing that some adults had better success with some structures to mean that there is no critical period for second language learning. But couldn’t the success of some adults over their younger counterparts be attributed to the possibility of advanced cognitive development, instead of the dismissal of an age-related device? Further, Bialystok concludes that because Birdsong, Bongaerts, and Juffs/Harrington, provide contradictory claims to Patkowsky and Johnson and Newport, that some adult learners

achieve native-like competence, there is no age-related device. Whereas this data is important, I do not feel it is definitive in refuting the existence of a sensitive period for language learning. Merely, these examples could be the exceptions, not the rule. Not only do adult successes in the above mentioned studies not disprove the existence of a sensitive period, but all can be attributed to outside factors. For example, in the grammaticality judgement tasks given by Birdsong, could the tasks have simply been developmentally beyond the capabilities of the children tested? I choose to lay my trust in the much larger stack of evidence that suggests this is so. Simply because a possibility in the general population is documented, it does not mean all other empirical studies showing overwhelming patterns should be disregarded. 2.) “At what age does a decline in learning a language commence?” There is much disagreement in the literature about the precise onset of a decline in the ability to learn a language. Patkowsky would assert that the age is 15 for morphology and syntax, while Newport/Johnson assert that for phonology it begins at age 6. Others, like Bialystok, assert that the delineation begins at the age of twenty.

Because there is much disagreement among

researchers on this point, it is difficult to assert an exact moment when a decline commences. It seems more acceptable to suggest that a decline in the ability to learn a second language exists at some point and is documented by most researchers. Since the ability to achieve competency varies to a great degree in adults and less so in children (who possess the same high proficiency capabilities), does this not in itself suggest an overall pattern of ability set on by age? Perhaps, the onset of a sensitive period changes according to the individual just as growth patterns and personal milestones are reached at different times in one’s life. Perhaps if future studies were to measure similar abilities under similar conditions, more consistent data would emerge. 3.) “What are the implications of these theories for second language teaching?” Johnson and Newport’s (1989) assertions have wide ranging implications for classroom teaching. They found that it is best to measure a learner’s first exposure to English as their age of arrival in the US, not the first formal instruction in English in their native country. Because of this, we can assume that formal instruction has less of an impact on one’s learning of English as compared with immersion in that culture or society. Johnson and Newport state:

More profoundly, it (the results of their study) means that the learning which occurs in the formal language classroom may be unlike the learning which occurs during immersion, such that early instruction does not necessarily have the advantage for ultimate performance that is held by early immersion (p. 81). Because of these findings, teachers need to be aware of the possible limitations that children and adults possess regarding initial achievement levels. Learners should be given appropriate time to become immersed in the language before being expected to produce the new language: with an even greater patience given to adults. Also, teachers should encourage as much interaction with the new culture (immersion) as possible and maximize the amount of exposure to the L2.

Conclusion Because data in many empirical studies is varied, researchers should in the future refine their questions by referring to the same specific empirical issues. When researchers search out the answers to similar questions, the results are telling. The Critical Period Hypothesis, stating that learners who are exposed to a second language before puberty have the propensity to acquire a native-like proficiency of the language, seems to hold true today with strong empirical research to support it. Unlike what some researchers propose, simply because an achievement is possible for some members of the general population, it does not mean that an entire hypothesis should be discarded.

Bibliography Bialystok, E. 1997: The structure of age: in search of barriers to second language acquisition. Second Language Research, 13, 116-137. Birdsong, D. 1992: Ultimate attainment in second language acquisition. Language 68, 706-55.

Bongarts, T., Planken, B. and Schills, E. 1995: Can late learners attain a native accent in a foreign language? A test of the critical period hypothesis. In Singleton, D. and Lengyel, Z. editors, The age factor in second language acquisition, Clevedon: Multilingual Matters, 30-50.

Johnson, J.S. and Newport, E.L. 1989: Critical period effects in second language learning: the influence of maturational state on the acquisition of English as a second language. Cognitive Psychology 21, 60-99.

Juffs, A., and Harrington, M. 1995: Parsing effects in L2 sentence processing: subject and object asymmetries in Wh-extraction. Studies in Second-Language Acquisition 17, 483-516.

Lenneberg, E. 1967: Biological foundations of language. New York: Wiley. Lightbown, P. and Spada, N. 1999: How languages are learned. Oxford: Oxford University Press. Long, M. 1990: Maturational constraints on language development. Studies in second language acquisition 12, 251-85. Patkowksy, M. 1980: The sensitive period for the acquisition of syntax in a second language. Language Learning 30, 449-72.

White, L. and Genesee, F. 1996: How native is near-native? The issue of ultimate attainment in adult second language acquisition. Second Language Research 12, 233-65. Gina La Porta Literature Review Professor Han A&HL 4087 Section 1 Due Date: May 8, 2000

A Critical Look at the Critical Period Hypothesis Introduction The purpose of this paper is to investigate the evidence of the Critical Period Hypothesis (Lenneberg 1967). Questions posed throughout this paper are: “Is there a critical period for learning a second language?” If so, “At what age does a decline in learning a language commence?” And finally, “What are the implications of these theories for second language teaching?” Articles written by Bialystok (1997), Johnson and Newport (1989), Long (1990), and Patkowsky (1980), are reviewed and commented upon in this paper.

Review of Material

Many researchers hold opposing beliefs about the Critical Period Hypothesis put forth by Lenneberg (1967). The hypothesis cited in Lightbown and Spada (1999) states that there is a “specific and limited time period for language acquisition”

(p. 19). Lenneberg believed that

the “language acquisition device, like other biological functions, works successfully only when it is stimulated at the right time” (p. 19). But what does further research suggest? Patkowsky (1980) suggests that a critical period for second language learning does indeed exist. His study meant to find out about the likelihood of a critical period for learning a second language. Patkowsky found that learners under the age of fifteen achieved higher syntactic proficiency than those who were over the age of fifteen at the onset of exposure. Patkowsky’s study included 67 highly educated immigrants a.) from various backgrounds b.) from various ages c.) who lived in the United States for various numbers of years, and d.) who had all lived in the United States for at least five years. Patkowsky used a control group of 15 native-born Americans. Judges employed a rating scale of 0 to 5. Five served as the most native–like level and 0 indicated almost no English capability. Judges rated written transcripts of tape-recorded interviews. The study sought to discern if learners who were exposed to second language learning before the age of 15 actually received higher syntactic proficiency than older learners. The results showed that of those who were exposed to English pre-puberty (participants up to the age of fifteen), all, (except one) achieved ratings of four through five whereas those in the postpuberty group received a wider range of scores, with the mean falling in the three range. “Thus, even at a purely descriptive level, the distributional characteristics of the two nonnative groups are clearly consonant with the notion of a sensitive period for the acquisition of syntax in a second language” (p. 454). This study was a departure from earlier studies since the most obvious measure of proficiency had previously been in the linguistic domain of phonology. Patkowsky posited that among all the factors he examined in his study, age was the factor that had the most significant impact of success in learning a second language. His findings are fully consistent with the Critical Period Hypothesis.

In their discussion of critical period effects in learning a second language, Johnson and Newport (1989) concede that there does indeed exist a critical period for second language learning. Johnson and Newport believe that after the age of six, the ability to learn a second language begins to decline. Johnson and Newport’s study involved 46 Chinese and Korean speakers learning English as a second language. Criteria included the following: a). subjects had at least five years of exposure to the language b.) they each had to have been living in the US for three years without leaving, and c.) subjects included were students and faculty at the college level. In this study, respondents were tested not only on syntax, but also on morphology, and were asked to judge the grammaticality of many sentences. Twelve rule types comprised the test, presenting a wide sampling of the English language. The results showed that “subjects who began acquiring English in the United States at an earlier age obtained higher scores on the test that those that began later” (p. 77). The results also show a correlation between the age of acquisition and the variance in the ultimate performance in adults. For example, they assert that there are few differences in the ultimate ability to learn language in learners before age 15. Adults, however, attain various levels of achievement. “While early learners are uniformly successful in acquiring their language to a high degree of proficiency, later learners show much greater individual variation” (p. 97). In further discussion of this proposed idea, they delineated between the alternate versions of the hypothesis. In the exercise hypothesis, it is believed that humans easily learn languages at an early age. As long as this capacity is exercised (at an early age), the theory proposes, a person’s ability to learn subsequent languages will always remain viable. The alternate version of the theories is known as the maturational state hypothesis. This hypothesis states that even though humans have a capacity to learn languages early in life, they are unable to do so with the same outcome if learning a second language commences in the future. Johnson and Newport believe that their findings support the maturational state hypothesis.

Johnson and Newport’s study also lends credence to the critical period hypothesis, but not in the manner that Lenneberg had proposed:

Lenneberg’s original proposal of a critical period in language acquisition seemed to predict a rectangular function in the relationship between age of acquisition and ultimate performance. That is, Lenneberg hypothesized that ‘normal’ language learning was possible between the period from infancy to puberty, with a loss of abilities after puberty (p. 95). Instead, Johnson and Newport (1989) found that “performance gradually declined from about age seven on, until adulthood” (p. 95). Thus according to Johnson and Newport’s research, the decline begins far before puberty, even before the threshold of fifteen years of age, as Patkowsky (1980) had found. In response to these and many other empirical studies, Long (1990), in his seminal paper, reviewed the second language research on age–related differences. In this paper he draws several conclusions that are relevant to this topic: 1. Both the initial rate of acquisition and the ultimate level of attainment depend in part on the age at which learning begins. 2. There are sensitive periods governing both first and second language development, during which both the acquisition of different linguistic domains is successful and after which it is incomplete. 3. The age-related loss of ability is cumulative, not a one-time event. 4. Deterioration in some individuals begins as early as six. In his review, Long spends much of his paper showing the flaws in the current research that purports that there is no age limitation on achieving native-like fluency. “Contrary to recent assertions in literature, there is growing evidence that maturational constraints are at work in second language learning, and that they are not confined to phonology” (p. 273). Long feels that the decline of linguistic ability while learning a second language is related not to cognitive abilities (as some propose) but to an age related device found to be before puberty. Long’s review gives support to both Patkowsky and Newport and Johnson (whose papers are both discussed in his review) in terms of the focus on age: Starting after age six appears to make it impossible for many learners (and after age 12 for the remainder) to achieve native-like competence in phonology; starting later than the early teens, more precisely after age 15, seems to create the same problems in morphology and syntax. (p. 274) Whereas Long feels the empirical evidence supports the Critical Period Hypothesis, he concludes his article by giving credence to some of the other explanations that might help to explain the

lack of ability in adults to achieve native-like competence in a second language. Affective, input, social, and neurological variables have all been used to discount the Critical Period Hypothesis. Long is inclined to give the most credence to neurological factors. “Incremental losses of plasticity with increasing brain maturation, possibly associated with myelination-if only by default, seems a more defensible position” (p. 280). In contrast to the above research, Bialystok (1997) wrote a paper that looks to deny the evidence supporting the notion of a critical period for language learning. According to Bialystok: It is undoubtedly the case that the descriptive statement regarding the general success of younger learners in acquiring a second language is true. However, the evidence does not provide convincing support for the claim that this advantage is the reflection of a sensitive period in learning (p. 133). Bialystok rather asserts that the “correspondence between language structures in the first and second language is the most important factor affecting acquisition” (p 116). She believes that successful language learners as adults can achieve the same success as children if they make the time and the space to learn and if they possess the motivation from which children usually benefit. Bialystok reviews research by Johnson and Newport (1989), yet questions their findings based on the following questions. Bialystok questions the subjects used, the structure of the research and the tasks they were given to complete. First, Bialystok cited a study (Bialystok and Hakuta, 1994) in response to the subjects used that reexamines the findings by Johnson and Newport. Bialystok and Hakuta reorganize the two segments of learners (those younger than 15 and those older than 15) into one group. Upon this re-examination, Bialystok asserts that the level where language noticeably declines is around the age of 20. This would mean that puberty, or a prepuberty finding for a decline in language acquisition is incorrect. Bialystok and Hakuta concur with Johnson/Newport’s claims that the younger learners perform similarly to each other, whereas the adult learners have a greater variety in performance. Bialystok does assert, however, that the variety in adult learners abilities include those who actually outperform the younger learners. She asserts that the languages of the Chinese/Korean learners could be considered weak and non-dominant, thus allowing English to assume the role

of the learners’ first, not second language, rendering many of the Johnson/Newport findings moot. Second, Bialystok negates the structures that gave the learners difficulty. She finds that the ability to detect errors in some, but not all of the structures did not vary with age. This, Bialystok feels, disproves the findings as well. Third, the method gives pause to Bialystok. She believes that the method of testing produced different results in two studies. This varied outcome, Bialystok believes, accounts for evidence that the outcomes could not be attributed to age factors. Bialystok cites a number of empirical studies by White and Genesee (1996), Birdsong (1992), Bongaerts (1995), and Juffs and Harrington (1995) which refute Patkowsky’s (1980) claims. For example, White and Genesee found that age made no difference in grammatical and phonological achievement. Likewise, Birdsong reported that some late learners were as proficient as younger learners on grammaticality tasks. Bongaerts found that late learners could achieve pronunciation levels at the same level as native speakers. Juffs and Harrington provide counter evidence to that of researchers such as Johnson/Newport and Patkowsky, by showing that some adult learners can achieve similar levels of success as younger learners. After supplying these data, Bialystok then admits that this evidence only serves as a minor segment of the total evidence on this subject. At this point Bialystok looks to the lack of adult success on outside factors other than age. Bialystok asserts that the relationship between languages is the reason for differences in attainment. The hypothesis is that language learners will find it difficult to master a structure that was not a defining feature of the first language and relatively easy to master a structure shared across the two languages. These differences may be exacerbated for older learners, but there should be no age differences in the ability to learn structures that are shared across the two languages (p. 126).

Discussion After reviewing the literature documented in this paper, I have confirmed my previous thoughts about the Critical Period Hypothesis. I believe that there does exist a critical period for learning

a second language. After the age of fifteen, there exists a regressive, diminished capability in learners to acquire a language. In certain linguistic domains, such as phonology, this may happen as early as the age of six. These findings present educators with serious implications for second language teaching. The following discussion is an attempt to answer the questions posed at the beginning of this paper. 1.) “Is there a critical period for learning a second language?” The evidence, in my opinion, seems to overwhelmingly state that there is indeed a critical period by which learning must commence in order to afford the learner with the chance to achieve native-like capabilities. It has been documented repeatedly that learners achieve better results depending on the age at which they begin to learn a second language. Even though some researchers try to attribute this phenomenon to other factors, I believe that there is an innate age-related factor. Bialystok’s proposal that interference between first and second language factors affects second language acquisition in adults, is suspect. If interference between two languages is the cause, why then does it not provide an overwhelming obstacle for sequential bilingual children, who have been seen to reach native-like proficiency in both languages? Also, Bialystok interprets Newport and Johnson’s (1989) study showing that some adults had better success with some structures to mean that there is no critical period for second language learning. But couldn’t the success of some adults over their younger counterparts be attributed to the possibility of advanced cognitive development, instead of the dismissal of an age-related device? Further, Bialystok concludes that because Birdsong, Bongaerts, and Juffs/Harrington, provide contradictory claims to Patkowsky and Johnson and Newport, that some adult learners achieve native-like competence, there is no age-related device. Whereas this data is important, I do not feel it is definitive in refuting the existence of a sensitive period for language learning. Merely, these examples could be the exceptions, not the rule. Not only do adult successes in the above mentioned studies not disprove the existence of a sensitive period, but all can be attributed to outside factors. For example, in the grammaticality judgement tasks given by Birdsong, could the tasks have simply been developmentally beyond the capabilities of the children tested? I choose to lay my trust in the much larger stack of evidence that suggests this is so. Simply

because a possibility in the general population is documented, it does not mean all other empirical studies showing overwhelming patterns should be disregarded. 2.) “At what age does a decline in learning a language commence?” There is much disagreement in the literature about the precise onset of a decline in the ability to learn a language. Patkowsky would assert that the age is 15 for morphology and syntax, while Newport/Johnson assert that for phonology it begins at age 6. Others, like Bialystok, assert that the delineation begins at the age of twenty.

Because there is much disagreement among

researchers on this point, it is difficult to assert an exact moment when a decline commences. It seems more acceptable to suggest that a decline in the ability to learn a second language exists at some point and is documented by most researchers. Since the ability to achieve competency varies to a great degree in adults and less so in children (who possess the same high proficiency capabilities), does this not in itself suggest an overall pattern of ability set on by age? Perhaps, the onset of a sensitive period changes according to the individual just as growth patterns and personal milestones are reached at different times in one’s life. Perhaps if future studies were to measure similar abilities under similar conditions, more consistent data would emerge. 3.) “What are the implications of these theories for second language teaching?” Johnson and Newport’s (1989) assertions have wide ranging implications for classroom teaching. They found that it is best to measure a learner’s first exposure to English as their age of arrival in the US, not the first formal instruction in English in their native country. Because of this, we can assume that formal instruction has less of an impact on one’s learning of English as compared with immersion in that culture or society. Johnson and Newport state:

More profoundly, it (the results of their study) means that the learning which occurs in the formal language classroom may be unlike the learning which occurs during immersion, such that early instruction does not necessarily have the advantage for ultimate performance that is held by early immersion (p. 81). Because of these findings, teachers need to be aware of the possible limitations that children and adults possess regarding initial achievement levels. Learners should be given appropriate time to become immersed in the language before being expected to produce the new language: with an

even greater patience given to adults. Also, teachers should encourage as much interaction with the new culture (immersion) as possible and maximize the amount of exposure to the L2.

Conclusion Because data in many empirical studies is varied, researchers should in the future refine their questions by referring to the same specific empirical issues. When researchers search out the answers to similar questions, the results are telling. The Critical Period Hypothesis, stating that learners who are exposed to a second language before puberty have the propensity to acquire a native-like proficiency of the language, seems to hold true today with strong empirical research to support it. Unlike what some researchers propose, simply because an achievement is possible for some members of the general population, it does not mean that an entire hypothesis should be discarded.

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Johnson, J.S. and Newport, E.L. 1989: Critical period effects in second language learning: the influence of maturational state on the acquisition of English as a second language. Cognitive Psychology 21, 60-99.

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