09-10-08 Aletha Slides

''

Lq

A

///

l{,Ftc"-

A.,t JJ 4Q*\('rr'q{niio'.s y^ \^ ftr,uu?lf

\

,, T ,. r_ 1 , , 4 K ^ \Ol_

1- tc-u(

L

t4bo r ( ' i o E

E

t :1,

BehavioralGenetics

I

I

Population{ased Hentfi sourcesof individualvariationwithin a populationwith a givendistribution of genesand :ii:"r environments.Calolatlonof a (heritability), c (shared (nonshared envircnment), 6 envimnment) I r basedonconerations. ldentirysourcesof meanchangein a population, usuallyovertime (e.9.Flynn,studiesof cohortand I r age) MEANSANDCORRELATIONS AREINDEPENDENT OF ONEANOTHER

!! '.:i-r

I

r r E

F

Replicatedlindings \Mthin populationsthat are primarilywhite, northemEuropeanancestryin Europeand the U.S.,there is evidencefor heritabilityof lQ, majorpsycfiopathology(schizophrenia and manicdepression),and a rangeof personalitycharacteristics.Basedprimarily on twin studiesand early adoptionstudiesof within-population variability.

F rlt5

.< t:.-\ -]- \>{

-.\ u

t I :':r:it

I il

Fr Aiioptianstudies- recentstr.rdies I leviervedin reading

Adoptionstudies Eady studias mostly about lQ: adopted at birth, U.S. parenls. Childrs Msasured lQ of biologi€l mother, adop,tive psrents and child- €iimildty (ffilalion) wilh bio rdher gEter tian eimil€rity (@relation) with .doptive paronts- BUT - Meil @6 of sdopled cfiibH d@r lo ti6e of ad@tiv6 pamts lhan to tho$ of tio pamts, €spo€iafly whs bb pasrls bald 10OMeasured lQ of adoptive parents, adoptEd cfiild, biologi€l child. -Corel8lids > @mlsiim d tio cfiiH with bio Ecnts of adoptld chiH with sre emis. -BUT mearuGd tryiMment al3o @relatad with adgpled cfiiHEn's lQs.

E-.!. I E q

r

F

r I I t

x

. Assume ad@led d{lden corE fiom sam€ g€retic distribution as lhose'l€fi b€hind.' - Assum€ adodive wimrerts significandy b€tts thm th€triginal eNimmmt. . Comparing to all cttilden in ntr ffvirontnent" not tho$ inchild'sadoptiwfarnily'

F

I

t r

- Mostlyintemationaladoptionsftom countries wherechildrenseverelydeprivedin infancy. - lssue:Gsilienceratherthanindividualvariability. but NotstudyingindivktualgEneticcharacteristics, influence. overallissueof environmental

Issuesin belravioralgerretics - twirr stuclies researoh Assumptions: MZ and DZ twins have equally similar envirorments (Suzanne) Not arguing lhsir environmenls are identical, but equally similar. QGditr this (Aison). Any difforEnce b€twe€n MZ twins must b€ d€ to envirmrent (shared and nonshared). Brendg€n anide. Twins and singletons have th6 sam€ relative onfibutim of g aqd e. That is, thtre is nothing specific ebqn b€ing twiru th€t affBcis the balance. Being adopted does not alt€rth€relativscontribution ofg and e, th€t is, thore is nolhing inh€rentabout b€ing adopted thal afieds llE balare. Aclootgd childran have lhe sre shered €flvimment as siblings in th6ir adoptive families.

b E I

a ..

I F F

Current Issues Meaning of lQ - lmmutable,unobservable?(lGryn) - Can it be free of cutfure,envionment? Contributions of g and e may vary by domain of development (fomo) - lQ vs acfiievement * Differentcognitivedomains(Canie) - Socialvs. physicalaggression - Corporalpunishmentvs. maltreatment

a2, Ecological framework

andsocialissues Methodologieal

- Timeimportant - Possible br partioilar oidcalpedods genee(Lauren) environments,

, : Problemof confounding acrossfour typesofgxe.

-Cumulativeeffectsale mostimportant (JodD .. Cultureas factor moderatingrclationssf g and e (Ghris)

- E.g. motherc' responsesto cfiiH may be funciion of g+ conelation, etc. (Ashley)

- ls modification of gene afitture therapeutictreatrnent(Nina)

2