Chapter 9: Human development
9.1 What factors shape infancy?
Prenatal period: conceptonn tonbir th
Infancy period: beginsna tnbir thnandnlas tsn18n ton24nmon ths
Childhood period: beginsna tn thenendnofninfancynandnlas tsnuntlnagesn11nandn14
Adolescence: beginsna tn thenendnofnchildhoodnandnlas tsnbe tweenn18nandn21nyears
Adulthood: beginsna tn thenendnofnadolescencenandnlas tsnuntlndea th
Prena talnenvironmen tncannafec tndevelopmen t
Thenprocessnbeginsna tn thenmomen tnofnconceptonnnwhenn thenspermnfromn thenmalenuni tesnwi thn theneggn
fromn thenfemalen toncrea ten thenzygotenn thenfrs tncellnofnannewnlife. n； tnabou tn2nweeksni tnisnimplan tedninn
thenu terinenwall. nFromnabou tn2nweeksn ton2nmon thsn thendevelopingnhumannisnknownnasnannembryo. n
Duringn thisns tagen thenorgansnandnin ternalnsys temsnbeginn tonform. nThenembryonisnvulnerablenandn
exposuren tonharmn(suchnasn toxinsnndrugsne tc. )ncannhavenlastngnefec ts. n；fern2nmon thsn thengrowingn
humannisncallednanfetusnandn thenhear tnbeginsn tonbea t. nMos tnpregnanciesnlas tsnbe tweenn38nandn42n
weeks. n
Brain development
Onenimpor tan tnwayn tha tnbrainncircui tsnma turenisn throughnmyelinaton. nThisnprocessnbeginsnonn then
spinalncordnduringn thenfrs tn trimes ternofnpregnancynandnonn thenneuronsnduringn thensecondn trimes ter. n
Thenmyelina tednaxonsnformnsynapsesnwi thno thernneurons. nThenbrainnisnhighlynplastccn thenbrainn
organizesni tselfninnresponsen toni tsnenvironmen talnexperiencesnnperseveringnsynaptcnconnectonsni tn
needsninnordern tonfunctonninnangivenncon tex tnandnpruningnou tno thers. nThisnprocessnisncallednsynaptic
pruning. nGenesnprovidenins tructonsnforn thenma turingnbrainnbu tnhown thenbrainnchangesnduringninfancyn
andnearlynchildhoodnisnalsonafec tednbynenvironmen t. n
Teratogens arenagen tsn tha tnharmn thenembryonornfe tus. nTheyncannimpairndevelopmen tninn thenwomb. n
Tera togensnincludendrugsnnalcoholnnbac teriannvirusesnandnchemicals. nThenmos tncommonn tera togennisn
alcohol. nI tncannleadn tonfetal alcohol syndrome (FAS). Thensymp tomsnarenlownbir thnweigh tnnfacenandn
headnabnormalitesnnfe talnalcoholnspec trumndisordersn(in tellec tualndisabili ty)nandnbehaviouralnandn
cognitvenproblems. nPrema turenbir thnisnassocia tednwi thn thenusenofndrugsnduringnpregnancy. nMenn
shouldnalsonbencautousnabou tn theirnhabi tsnifn therenisnanpossibili tyn tha tn theynfa thern thenchildren.
Dynamicnsys temsn theorynillumina tesn thenwaysnbiologynandnenvironmen tnworkn toge thern tonshapen
developmen t
Newbornsnhavenvariousnmo tornrefexesn tha tnaidnsurvivalcn thengrasping refex, the rootng refex
(au tomatcnsuckingnwhennannobjec tncomesnnearn theirnmou ths)nand the sucking refex. Findingsnofn
diferen tns tudiesnillus tra ten thenimpor tancenofnsocializatonnexperiencesnandnparen talngoalsninn then
developmen tnofninfan tnmo tornskills. n
Dynamic systems theory viewsndevelopmen tnasnanself-organizingnprocessnninnwhichnnewnformsnofn
behaviornemergen throughnconsis ten tnin teractonsnbe tweennanbiologicalnbeingnandncul turalnandn
environmen talncon tex ts. nI tnoccursn throughn thenperson’snactvenexploratonnofnannenvironmen tnandn then
cons tan tnfeedbackn tha tn thenenvironmen tnprovides. n
Keynresearchnfndingsnonninfan tnlearningnandninfan tnmemory
Newbornsncomenin ton thenworldnwi thnfairlynwell-developednpercep tualnskillsn(smellingnnhearingne tc. ). n
；l thoughnsomenofn thesenskillsnarenno tnfullyndevelopedna tnbir thnn thennewbornnisnablen tonprocessnan
considerablenrangenofnsensorynstmuli. nThenabili tyn tondistnguishndiferencesnamongnshapesnnpaternsn
andncolorsnisnknownnasnvisual acuity. Researchersnusen thenpreferentalllooking technique innwhichn then
,researchersnshownanninfan tn twon thingscnifn theninfan tnlooksnlongerna tnonenofn then thinsn thenresearchersn
known theninfan tncanndistnguishnbe tweenn then twonandnfndsnonenmorenin terestng. n
Childrennarenablen tonusennewninformatonn tonbuildnonnwha tn theynalreadynknow. nMos tnadul tsnremember
fewneven tsn tha tnoccurrednbeforen theynweren3norn4nyearsnold. nFreudnreferredn ton thisninabili tyn ton
rememberneven tnformnearlynchildhoodnasninfantile amnesia. nInfantlenamnesianmayndisappearnwi thn
thendevelopmen tnofnlanguage. n
Infan tsnarenallncapablenofnlearningnal thoughninformatonnofnexplici tnlong- termnmemoriesndoesnno tn
occurnuntlnabou tn thenagenofn18nmon ths. n
Thendiferen tn typesnofnatachmen tn theninfan tsnhaven ton theirncaregivers
Onenfundamen talnneedninfan tsnhavenisn tonbondnemotonallynwi thn thosenwhoncarenforn them. n；nn
attachmentnisnans trongnnintma tennemotonalnconnectonnbe tweennpeoplen tha tnpersis tsnoverntmenandn
acrossncircums tances. nCaregiversnshapenmuchnofnanninfan t’snearlynexperience. n；tachmen tnisnadaptvee
i tnisnandynamicnrelatonshipn tha tnfacili ta tesnsurvivalnforn theninfan tnandnparen talninves tmen tnforn then
caregivers. n
；tachmen tnisnimpor tan tnfornsurvivalninnmanyno thernspeciesnasnwell. nFornexamplenbirdsnn theynwillnatach
themselvesnnwi thinn18nhoursnafernha tchingnn tonannadul tn(mos tlyn theirnmo thers)nandn thennfollown then
objec tnofn theirnatachmen t. nThisnbehaviornisncallednimprintng. n
HarrynHarlowndiscoverednonenofn thenmos tns trikingnexamplesnofnnonhumannatachmen t. nHenrecognizedn
tha tn thenmonkeyninfan tsnneededncomfor tnandnsecuri tyninnadditonn tonfood. nHisnfndingsnes tablishedn the
impor tancenofncontact comfort -n thenimpor tancenofnphysicaln touchnandnreassurancen-ninnaidingnsocialn
developmen t. n
； tnaroundn8n ton12nmon thsninfan tsndisplaynseparaton anxiety. nTha tnisnnwhenn theninfan tsncanno tnseenorn
arensepara tednfromn theirnatachmen tnfguresnornarenlefnwi thnbabysitersnn theynmaynbecomenveryn
dis tressed. nTons tudynatachmen tn；inswor thncrea tedn thenstrangelsituaton test. Thenex ten tn tonwhichn
thenchildncopesnwi thndis tressnandn thens tra tegiesnhenornshenusesn tondonsonindica ten thenquali tynofn then
child’snatachmen tn ton thencaregiver. n；inswor thnidentfedninfan t/caregivernpairsn tha tnappearednsecure
asnwellnasn thosen tha tnappearedninsecure ornanxious.
l Secure attachment appliesn tonapproxima telyn60-65npercen tnofn thenchildren. n；nsecurenchildnisn
happyn tonplaynalonenandnisnfriendlyn ton thens trangernasnlongnasn thenatachmen tnfgurenisnpresen t.
Whenn thenatachmen tnfgurenleavesn thenroomnn thenchildnisndis tressed. nThenchildnisnquicklyn
comfor tednwhenn thenfgurenre turns. n
l Insecure (anxious) attachment appliesn ton35-40npercen tnofnchildren. nI tncann takenmanynformsnn
fromnanninfan t’sncomple telynavoidingncon tac tnwi thn thencaregivern ton theninfan tnactvelynhiingn
ornexhibitngnangrynfacialnexpressionsn towardsn thencaregiver. n
o Childrennwi thnavoidant atachmen tndonno tnge tnupse tnwhenn thencaregivernleaves.
o Childrennwi thnambivalent (anxious/resistant) atachmen tnmayncrynangrea tndealnwhenn
thencaregivernleavesnbu tn thennbeninconsolablenwhenn thencaregivern triesn toncalmn themn
downnuponnre turn. n
Researchersndiscoveredn tha tn thenhormonenoxytocin isnrela tedn tonsocialnbehaviors. nI tnplaysnanroleninn
ma ternaln tendenciesnnfeelingsnofnsocialnaccep tancenandnbonding. nInn thenmo thernandn theninfan tnn
oxy tocinnpromo tesnbehaviorsn tha tnensuren thensurvivalnofn thenyoung. n
,9.2 How do children learn about the world?
Thens tagesnofndevelopmen tnproposednbynPiage t
ThroughncarefulnobservatonsnofnyoungnchildrennnJeannPiage tndevisednanninfuentaln theorynabou tn then
developmen tnofn thinking. nOnencrucialnaspec tnofnhisnresearchnisn tha tnhenpaidnasnmuchnatentonn tonhown
childrennmakenerrorsnasn tonhown theynsucceednonn tasks. nHendevelopedn then theoryn tha tnchildrenngon
throughnfournstages of developmentnnwhichnrefec tndiferen tnwaysnofn thinkingnabou tn thenworld. nHen
proposedn tha tnnewnschemes arenformednduringneachns tage. nSchemesnarenwaysnofn thinkingnbasesnonn
personalnexperience. nThroughnassimilation: annewnexperiencenisnplacednin tonannexistngnschemenn
throughnaccommodation: annewnschemenisncrea tednornannexistngnonenisndramatcallynal teredn ton
includennewninformatonn tha tno therwisenwouldnno tnf tnin ton thenscheme. n
1. Sensorimotor stage (birth to 2 years): duringn thisnperiodnchildrennarenfrmlynsi tua tedninn then
presen tnandnacquireninformatonnprimarilyn throughn theirnsensesnandnmo tornexploraton. n
o Theirnunders tandingnofnobjec tsnoccursnwhenn theynrefexivelynreac tn ton thensensoryn
inpu tnfromn thosenobjec ts. n
o Theynbecomencapablen tonmen tallynrepresentngn theirnworldnandnexperiencesnwi thn
increasinglyncomplexnschemes. n
o Refexivenresponsesndevelopnin tonmorendelibera tenactonsn throughn thendevelopmen tn
andnrefnemen tnofnschemes
o Object permanence: thenunders tandingn tha tnannobjec tncontnuesn tonexi tsnevennwhenn
i tsnhiddennfromnview. n
2. Preoperational stage (2 to 7 years): childrenncannbeginn ton thinknabou tnobjec tsnno tninn theirn
immedia tenviewnandn theynhavendevelopednconcep tualnmodelsnofnhown thenworldnworks. n
o Childrennbeginn ton thinknsymbolically. nTheynperformnin tuitvenreasoningnbasednonn
superfcialnappearancesn(ex. nlawnofnconservatonnofnquant ty).
o Lacknofnconservatonnskillsnisn though tn tonbenduen tonankeyncognitvenlimi tatonnofn then
preoperatonalnperiodencentraton. nThisnlimi tatonnoccursnwhennanpre-schoolerncanno tn
thinknabou tnmoren thannonende tailnofnproblem-solvingn taskna tnantme. n
o ；no therncognitvenlimi tatonncharac teristcnofn thenpreoperatonalnperiodnisn
egocentrism. nThisnrefersn ton then tendencynfornpreoperatonaln thinkersn tonviewn then
worldn throughn theirnownnexperiences. n
3. Concrete operational stage (7 to 12 years): childrennremainninn thisns tagenuntlnadolescence. n
Humansndonno tndevelopnlogicnuntln theynbeginn tonperformnmen talnrepresen tatons.
o Thenfrs tns tagenisnperformingnmen talnoperatonsnonnac tualnconcre tenobjec ts. n；nclassicn
operaton isnannactonn tha tncannbenundonennsuchnasn turningn thenligh tnonnandnof. nThen
abili tyn tonunders tandn tha tnannactonnisnreversiblenenablesnchildrenn tonbeginn ton
unders tandn thenconcep tsnsuchnasnconservatonnofnquant ty. n
o Childrenncannreasonnlogicallynabou tnanproblemnandnbeginn tonunders tandnwi thnmuchn
morendep thnhowno thernpeoplenviewn thenworldnandnviewnabou tn things. n
4. Formal operational stagen(12 years and up): individualsncannreasonninnsophistca tednandn
abs trac tnways. nI tnisn thenfnalns tagenofncognitvendevelopmen t. n
o I tninvolvesncritcaln thinkingnwhichnisncharac terisednbyn thenabili tyn tonformnanhypo thesisn
abou tnsome thingnandn tes tn thenhypo thesisn throughndeductvenlogic. n
o Involvesnusingninformatonn tonsys tematcallynfndnanswersn tonproblems.
Challengesn tonPiage t’sn theory
- Piage t’snframeworknleavesnlitlenroomnforndiferingncognitvens tra tegiesnornskillsnamongn
individualsn–nornamongncul tures. nCul turalnvaluesnshapenhownpeoplen thinknabou tnandnrela ten ton
thenworldnaroundn them. n
, - Vygo tskynemphasizednsocialnrelatonsnovernobjec tsninn thinkingnabou tncognitvendevelopmen t. n
Hendistnguishednbe tweennelemen tarynmen talnfunctonsnandnhighernmen talnfunctons. nCen traln
tonhisn theoriesnisn thenidean tha tnsocialnandncul turalncon tex tninfuencenlanguagendevelopmen t. n
Fromn thisnperspectvennyourn though tsnarenbasednonn thenlanguagenyounhavenacquiredn throughn
yournsocie tynandnyourncul turennandn thisnongoingninnernspeechnrefec tsnhigher-orderncognitven
processes. n
- ；no thernchallengenisn tha tnmanynchildrennmovenbacknandnfor thnbe tweenns tagesnifn theynaren
workingnonn tasksn tha tnrequirenvaryingnskillnlevels. n
- Innhisnvariousn testngnpro tocolsnPiage tnmaynhavenconfusedninfan t’sncognitvenabilitesnwi thn their
physicalnabilites. n
- I tnmaynunderestma tenearlynknowledge. nFornexampleninfan tsncannusenlawsnofnphysicsnandnevenn
demons tra tenanbasisnunders tandingnofnadditonnandnsub tracton. n
o S tudiesnrelynonn thenorientng refexenhuman’sn tendencyn tonpaynmorenatentonn tonnewn
stmulin thann tonstmulin tonwhichn theynhavenbecomenhabi tua ted. n
Theorynofnmindnandni tsnsignifcancenforndevelopmen t
Humansnhavenanninna tenabili tyn tonunders tandn tha tno thersnhavenmindsnandn tha tn thosenmindsnhaven
desiresnnin tentonsnnbeliefsnandnmen talns ta tes. nPeoplenarenablen tonformnnwi thnsomendegreenofnaccuracyn
theoriesnabou tnwha tn thosendesiresnnbeliefsnandnmen talns ta tesnare. nThisnabili tynisndescribednasntheory of
minden thenabili tyn tonunders tandn tha tno thernpeoplenhavenmen talns ta tesn tha tninfuencen theirnbehavior. n
Fromn tha tnwenantcipa ten theno thernperson’snbehavior. nTheorynofnmindnisndevelopednbyn15nmon thsnnand
i tnisnrela tedn ton thendevelopmen tnofn thenfron talnlobes. n
Theoriesnofnmoralnreasoningnandnmoralnemotons
Morali tynisndividednin tonmoral reasoning dependsnonncognitvenprocessesnandnin tonmoral emotons.
Kohlbergndevisednan theorynofnmoralnjudgmen tn tha tninvolvedn threenmainnlevelsnofnmoralnreasoninge
- Preconventional levelenpeoplenclassifynanswersninn termsnofnself-in teres tnornpleasurablen
ou tcomes. n；voidnpersonalnharm. n
- Conventional level: people’snresponsesnconformn tonrulesnofnlandnandnordernornfocusnonn
o thers’ndisapproval. n
- Postconventional level: thenhighes tnlevel. nPeople’snresponsesncen ternaroundncomplexn
reasoningnabou tnabs trac tnprinciplesnandn thenvaluenofnallnlife. n
Theoriesnofnmoralnreasoningnhavenbeenncritcizednfornbeingngendernandncul turenbiasednandnfornignoring
emotonalnaspec tsnofnmoralndecisions. nResearchnonnchildren’snmoralnemotonsnhavenfocusednlargelynon
empathy nandnsympathy. Empa thyn(inlevingsvermogen)ninvolvesnunders tandingnano ther’snemotonaln
s ta tenandnreliesnonn theorynofnmind. nSympa thyn(medeleven)narisesnfromnfeelingsnofnconcernnnpi tynorn
sorrownfornano ther. n
；ccordingn ton thensocial intuitionist modelnnmoralnjudgmen tsnrefec tnpeople’sninitalnandnau tomatcn
emotonalnresponsesnra thern thannconsciousndecisionsnbasednonnmoralnrules. n
Thenprefron talncor texnn theninsulanandn thenamygdalanaren threenofn thenbrainnareasninvolvedninnmoraln
thinking.
9.3 What changes during adolescence?
Biologynandnenvironmen tnin terac tn toninfuencenpuber ty
Biologicallynnadolescencenisncharac terizednbyn thenonse tnofnsexualnma turi tynandn thenabili tyn ton
reproducennwhichnisncallednpuberty. nThisnroughlyn two-yearndevelopmen talnperiodnmarksn thenbeginning
ofnadolescence. nDuringnpuber tynnhormonenlevelsnincreasen throughou tn thenbody. nThenincreasedn
hormonesnstmula tenphysicalnchanges. nFornexamplen thenadolescent growth spurtnnanrapidnnhormonallyn
9.1 What factors shape infancy?
Prenatal period: conceptonn tonbir th
Infancy period: beginsna tnbir thnandnlas tsn18n ton24nmon ths
Childhood period: beginsna tn thenendnofninfancynandnlas tsnuntlnagesn11nandn14
Adolescence: beginsna tn thenendnofnchildhoodnandnlas tsnbe tweenn18nandn21nyears
Adulthood: beginsna tn thenendnofnadolescencenandnlas tsnuntlndea th
Prena talnenvironmen tncannafec tndevelopmen t
Thenprocessnbeginsna tn thenmomen tnofnconceptonnnwhenn thenspermnfromn thenmalenuni tesnwi thn theneggn
fromn thenfemalen toncrea ten thenzygotenn thenfrs tncellnofnannewnlife. n； tnabou tn2nweeksni tnisnimplan tedninn
thenu terinenwall. nFromnabou tn2nweeksn ton2nmon thsn thendevelopingnhumannisnknownnasnannembryo. n
Duringn thisns tagen thenorgansnandnin ternalnsys temsnbeginn tonform. nThenembryonisnvulnerablenandn
exposuren tonharmn(suchnasn toxinsnndrugsne tc. )ncannhavenlastngnefec ts. n；fern2nmon thsn thengrowingn
humannisncallednanfetusnandn thenhear tnbeginsn tonbea t. nMos tnpregnanciesnlas tsnbe tweenn38nandn42n
weeks. n
Brain development
Onenimpor tan tnwayn tha tnbrainncircui tsnma turenisn throughnmyelinaton. nThisnprocessnbeginsnonn then
spinalncordnduringn thenfrs tn trimes ternofnpregnancynandnonn thenneuronsnduringn thensecondn trimes ter. n
Thenmyelina tednaxonsnformnsynapsesnwi thno thernneurons. nThenbrainnisnhighlynplastccn thenbrainn
organizesni tselfninnresponsen toni tsnenvironmen talnexperiencesnnperseveringnsynaptcnconnectonsni tn
needsninnordern tonfunctonninnangivenncon tex tnandnpruningnou tno thers. nThisnprocessnisncallednsynaptic
pruning. nGenesnprovidenins tructonsnforn thenma turingnbrainnbu tnhown thenbrainnchangesnduringninfancyn
andnearlynchildhoodnisnalsonafec tednbynenvironmen t. n
Teratogens arenagen tsn tha tnharmn thenembryonornfe tus. nTheyncannimpairndevelopmen tninn thenwomb. n
Tera togensnincludendrugsnnalcoholnnbac teriannvirusesnandnchemicals. nThenmos tncommonn tera togennisn
alcohol. nI tncannleadn tonfetal alcohol syndrome (FAS). Thensymp tomsnarenlownbir thnweigh tnnfacenandn
headnabnormalitesnnfe talnalcoholnspec trumndisordersn(in tellec tualndisabili ty)nandnbehaviouralnandn
cognitvenproblems. nPrema turenbir thnisnassocia tednwi thn thenusenofndrugsnduringnpregnancy. nMenn
shouldnalsonbencautousnabou tn theirnhabi tsnifn therenisnanpossibili tyn tha tn theynfa thern thenchildren.
Dynamicnsys temsn theorynillumina tesn thenwaysnbiologynandnenvironmen tnworkn toge thern tonshapen
developmen t
Newbornsnhavenvariousnmo tornrefexesn tha tnaidnsurvivalcn thengrasping refex, the rootng refex
(au tomatcnsuckingnwhennannobjec tncomesnnearn theirnmou ths)nand the sucking refex. Findingsnofn
diferen tns tudiesnillus tra ten thenimpor tancenofnsocializatonnexperiencesnandnparen talngoalsninn then
developmen tnofninfan tnmo tornskills. n
Dynamic systems theory viewsndevelopmen tnasnanself-organizingnprocessnninnwhichnnewnformsnofn
behaviornemergen throughnconsis ten tnin teractonsnbe tweennanbiologicalnbeingnandncul turalnandn
environmen talncon tex ts. nI tnoccursn throughn thenperson’snactvenexploratonnofnannenvironmen tnandn then
cons tan tnfeedbackn tha tn thenenvironmen tnprovides. n
Keynresearchnfndingsnonninfan tnlearningnandninfan tnmemory
Newbornsncomenin ton thenworldnwi thnfairlynwell-developednpercep tualnskillsn(smellingnnhearingne tc. ). n
；l thoughnsomenofn thesenskillsnarenno tnfullyndevelopedna tnbir thnn thennewbornnisnablen tonprocessnan
considerablenrangenofnsensorynstmuli. nThenabili tyn tondistnguishndiferencesnamongnshapesnnpaternsn
andncolorsnisnknownnasnvisual acuity. Researchersnusen thenpreferentalllooking technique innwhichn then
,researchersnshownanninfan tn twon thingscnifn theninfan tnlooksnlongerna tnonenofn then thinsn thenresearchersn
known theninfan tncanndistnguishnbe tweenn then twonandnfndsnonenmorenin terestng. n
Childrennarenablen tonusennewninformatonn tonbuildnonnwha tn theynalreadynknow. nMos tnadul tsnremember
fewneven tsn tha tnoccurrednbeforen theynweren3norn4nyearsnold. nFreudnreferredn ton thisninabili tyn ton
rememberneven tnformnearlynchildhoodnasninfantile amnesia. nInfantlenamnesianmayndisappearnwi thn
thendevelopmen tnofnlanguage. n
Infan tsnarenallncapablenofnlearningnal thoughninformatonnofnexplici tnlong- termnmemoriesndoesnno tn
occurnuntlnabou tn thenagenofn18nmon ths. n
Thendiferen tn typesnofnatachmen tn theninfan tsnhaven ton theirncaregivers
Onenfundamen talnneedninfan tsnhavenisn tonbondnemotonallynwi thn thosenwhoncarenforn them. n；nn
attachmentnisnans trongnnintma tennemotonalnconnectonnbe tweennpeoplen tha tnpersis tsnoverntmenandn
acrossncircums tances. nCaregiversnshapenmuchnofnanninfan t’snearlynexperience. n；tachmen tnisnadaptvee
i tnisnandynamicnrelatonshipn tha tnfacili ta tesnsurvivalnforn theninfan tnandnparen talninves tmen tnforn then
caregivers. n
；tachmen tnisnimpor tan tnfornsurvivalninnmanyno thernspeciesnasnwell. nFornexamplenbirdsnn theynwillnatach
themselvesnnwi thinn18nhoursnafernha tchingnn tonannadul tn(mos tlyn theirnmo thers)nandn thennfollown then
objec tnofn theirnatachmen t. nThisnbehaviornisncallednimprintng. n
HarrynHarlowndiscoverednonenofn thenmos tns trikingnexamplesnofnnonhumannatachmen t. nHenrecognizedn
tha tn thenmonkeyninfan tsnneededncomfor tnandnsecuri tyninnadditonn tonfood. nHisnfndingsnes tablishedn the
impor tancenofncontact comfort -n thenimpor tancenofnphysicaln touchnandnreassurancen-ninnaidingnsocialn
developmen t. n
； tnaroundn8n ton12nmon thsninfan tsndisplaynseparaton anxiety. nTha tnisnnwhenn theninfan tsncanno tnseenorn
arensepara tednfromn theirnatachmen tnfguresnornarenlefnwi thnbabysitersnn theynmaynbecomenveryn
dis tressed. nTons tudynatachmen tn；inswor thncrea tedn thenstrangelsituaton test. Thenex ten tn tonwhichn
thenchildncopesnwi thndis tressnandn thens tra tegiesnhenornshenusesn tondonsonindica ten thenquali tynofn then
child’snatachmen tn ton thencaregiver. n；inswor thnidentfedninfan t/caregivernpairsn tha tnappearednsecure
asnwellnasn thosen tha tnappearedninsecure ornanxious.
l Secure attachment appliesn tonapproxima telyn60-65npercen tnofn thenchildren. n；nsecurenchildnisn
happyn tonplaynalonenandnisnfriendlyn ton thens trangernasnlongnasn thenatachmen tnfgurenisnpresen t.
Whenn thenatachmen tnfgurenleavesn thenroomnn thenchildnisndis tressed. nThenchildnisnquicklyn
comfor tednwhenn thenfgurenre turns. n
l Insecure (anxious) attachment appliesn ton35-40npercen tnofnchildren. nI tncann takenmanynformsnn
fromnanninfan t’sncomple telynavoidingncon tac tnwi thn thencaregivern ton theninfan tnactvelynhiingn
ornexhibitngnangrynfacialnexpressionsn towardsn thencaregiver. n
o Childrennwi thnavoidant atachmen tndonno tnge tnupse tnwhenn thencaregivernleaves.
o Childrennwi thnambivalent (anxious/resistant) atachmen tnmayncrynangrea tndealnwhenn
thencaregivernleavesnbu tn thennbeninconsolablenwhenn thencaregivern triesn toncalmn themn
downnuponnre turn. n
Researchersndiscoveredn tha tn thenhormonenoxytocin isnrela tedn tonsocialnbehaviors. nI tnplaysnanroleninn
ma ternaln tendenciesnnfeelingsnofnsocialnaccep tancenandnbonding. nInn thenmo thernandn theninfan tnn
oxy tocinnpromo tesnbehaviorsn tha tnensuren thensurvivalnofn thenyoung. n
,9.2 How do children learn about the world?
Thens tagesnofndevelopmen tnproposednbynPiage t
ThroughncarefulnobservatonsnofnyoungnchildrennnJeannPiage tndevisednanninfuentaln theorynabou tn then
developmen tnofn thinking. nOnencrucialnaspec tnofnhisnresearchnisn tha tnhenpaidnasnmuchnatentonn tonhown
childrennmakenerrorsnasn tonhown theynsucceednonn tasks. nHendevelopedn then theoryn tha tnchildrenngon
throughnfournstages of developmentnnwhichnrefec tndiferen tnwaysnofn thinkingnabou tn thenworld. nHen
proposedn tha tnnewnschemes arenformednduringneachns tage. nSchemesnarenwaysnofn thinkingnbasesnonn
personalnexperience. nThroughnassimilation: annewnexperiencenisnplacednin tonannexistngnschemenn
throughnaccommodation: annewnschemenisncrea tednornannexistngnonenisndramatcallynal teredn ton
includennewninformatonn tha tno therwisenwouldnno tnf tnin ton thenscheme. n
1. Sensorimotor stage (birth to 2 years): duringn thisnperiodnchildrennarenfrmlynsi tua tedninn then
presen tnandnacquireninformatonnprimarilyn throughn theirnsensesnandnmo tornexploraton. n
o Theirnunders tandingnofnobjec tsnoccursnwhenn theynrefexivelynreac tn ton thensensoryn
inpu tnfromn thosenobjec ts. n
o Theynbecomencapablen tonmen tallynrepresentngn theirnworldnandnexperiencesnwi thn
increasinglyncomplexnschemes. n
o Refexivenresponsesndevelopnin tonmorendelibera tenactonsn throughn thendevelopmen tn
andnrefnemen tnofnschemes
o Object permanence: thenunders tandingn tha tnannobjec tncontnuesn tonexi tsnevennwhenn
i tsnhiddennfromnview. n
2. Preoperational stage (2 to 7 years): childrenncannbeginn ton thinknabou tnobjec tsnno tninn theirn
immedia tenviewnandn theynhavendevelopednconcep tualnmodelsnofnhown thenworldnworks. n
o Childrennbeginn ton thinknsymbolically. nTheynperformnin tuitvenreasoningnbasednonn
superfcialnappearancesn(ex. nlawnofnconservatonnofnquant ty).
o Lacknofnconservatonnskillsnisn though tn tonbenduen tonankeyncognitvenlimi tatonnofn then
preoperatonalnperiodencentraton. nThisnlimi tatonnoccursnwhennanpre-schoolerncanno tn
thinknabou tnmoren thannonende tailnofnproblem-solvingn taskna tnantme. n
o ；no therncognitvenlimi tatonncharac teristcnofn thenpreoperatonalnperiodnisn
egocentrism. nThisnrefersn ton then tendencynfornpreoperatonaln thinkersn tonviewn then
worldn throughn theirnownnexperiences. n
3. Concrete operational stage (7 to 12 years): childrennremainninn thisns tagenuntlnadolescence. n
Humansndonno tndevelopnlogicnuntln theynbeginn tonperformnmen talnrepresen tatons.
o Thenfrs tns tagenisnperformingnmen talnoperatonsnonnac tualnconcre tenobjec ts. n；nclassicn
operaton isnannactonn tha tncannbenundonennsuchnasn turningn thenligh tnonnandnof. nThen
abili tyn tonunders tandn tha tnannactonnisnreversiblenenablesnchildrenn tonbeginn ton
unders tandn thenconcep tsnsuchnasnconservatonnofnquant ty. n
o Childrenncannreasonnlogicallynabou tnanproblemnandnbeginn tonunders tandnwi thnmuchn
morendep thnhowno thernpeoplenviewn thenworldnandnviewnabou tn things. n
4. Formal operational stagen(12 years and up): individualsncannreasonninnsophistca tednandn
abs trac tnways. nI tnisn thenfnalns tagenofncognitvendevelopmen t. n
o I tninvolvesncritcaln thinkingnwhichnisncharac terisednbyn thenabili tyn tonformnanhypo thesisn
abou tnsome thingnandn tes tn thenhypo thesisn throughndeductvenlogic. n
o Involvesnusingninformatonn tonsys tematcallynfndnanswersn tonproblems.
Challengesn tonPiage t’sn theory
- Piage t’snframeworknleavesnlitlenroomnforndiferingncognitvens tra tegiesnornskillsnamongn
individualsn–nornamongncul tures. nCul turalnvaluesnshapenhownpeoplen thinknabou tnandnrela ten ton
thenworldnaroundn them. n
, - Vygo tskynemphasizednsocialnrelatonsnovernobjec tsninn thinkingnabou tncognitvendevelopmen t. n
Hendistnguishednbe tweennelemen tarynmen talnfunctonsnandnhighernmen talnfunctons. nCen traln
tonhisn theoriesnisn thenidean tha tnsocialnandncul turalncon tex tninfuencenlanguagendevelopmen t. n
Fromn thisnperspectvennyourn though tsnarenbasednonn thenlanguagenyounhavenacquiredn throughn
yournsocie tynandnyourncul turennandn thisnongoingninnernspeechnrefec tsnhigher-orderncognitven
processes. n
- ；no thernchallengenisn tha tnmanynchildrennmovenbacknandnfor thnbe tweenns tagesnifn theynaren
workingnonn tasksn tha tnrequirenvaryingnskillnlevels. n
- Innhisnvariousn testngnpro tocolsnPiage tnmaynhavenconfusedninfan t’sncognitvenabilitesnwi thn their
physicalnabilites. n
- I tnmaynunderestma tenearlynknowledge. nFornexampleninfan tsncannusenlawsnofnphysicsnandnevenn
demons tra tenanbasisnunders tandingnofnadditonnandnsub tracton. n
o S tudiesnrelynonn thenorientng refexenhuman’sn tendencyn tonpaynmorenatentonn tonnewn
stmulin thann tonstmulin tonwhichn theynhavenbecomenhabi tua ted. n
Theorynofnmindnandni tsnsignifcancenforndevelopmen t
Humansnhavenanninna tenabili tyn tonunders tandn tha tno thersnhavenmindsnandn tha tn thosenmindsnhaven
desiresnnin tentonsnnbeliefsnandnmen talns ta tes. nPeoplenarenablen tonformnnwi thnsomendegreenofnaccuracyn
theoriesnabou tnwha tn thosendesiresnnbeliefsnandnmen talns ta tesnare. nThisnabili tynisndescribednasntheory of
minden thenabili tyn tonunders tandn tha tno thernpeoplenhavenmen talns ta tesn tha tninfuencen theirnbehavior. n
Fromn tha tnwenantcipa ten theno thernperson’snbehavior. nTheorynofnmindnisndevelopednbyn15nmon thsnnand
i tnisnrela tedn ton thendevelopmen tnofn thenfron talnlobes. n
Theoriesnofnmoralnreasoningnandnmoralnemotons
Morali tynisndividednin tonmoral reasoning dependsnonncognitvenprocessesnandnin tonmoral emotons.
Kohlbergndevisednan theorynofnmoralnjudgmen tn tha tninvolvedn threenmainnlevelsnofnmoralnreasoninge
- Preconventional levelenpeoplenclassifynanswersninn termsnofnself-in teres tnornpleasurablen
ou tcomes. n；voidnpersonalnharm. n
- Conventional level: people’snresponsesnconformn tonrulesnofnlandnandnordernornfocusnonn
o thers’ndisapproval. n
- Postconventional level: thenhighes tnlevel. nPeople’snresponsesncen ternaroundncomplexn
reasoningnabou tnabs trac tnprinciplesnandn thenvaluenofnallnlife. n
Theoriesnofnmoralnreasoningnhavenbeenncritcizednfornbeingngendernandncul turenbiasednandnfornignoring
emotonalnaspec tsnofnmoralndecisions. nResearchnonnchildren’snmoralnemotonsnhavenfocusednlargelynon
empathy nandnsympathy. Empa thyn(inlevingsvermogen)ninvolvesnunders tandingnano ther’snemotonaln
s ta tenandnreliesnonn theorynofnmind. nSympa thyn(medeleven)narisesnfromnfeelingsnofnconcernnnpi tynorn
sorrownfornano ther. n
；ccordingn ton thensocial intuitionist modelnnmoralnjudgmen tsnrefec tnpeople’sninitalnandnau tomatcn
emotonalnresponsesnra thern thannconsciousndecisionsnbasednonnmoralnrules. n
Thenprefron talncor texnn theninsulanandn thenamygdalanaren threenofn thenbrainnareasninvolvedninnmoraln
thinking.
9.3 What changes during adolescence?
Biologynandnenvironmen tnin terac tn toninfuencenpuber ty
Biologicallynnadolescencenisncharac terizednbyn thenonse tnofnsexualnma turi tynandn thenabili tyn ton
reproducennwhichnisncallednpuberty. nThisnroughlyn two-yearndevelopmen talnperiodnmarksn thenbeginning
ofnadolescence. nDuringnpuber tynnhormonenlevelsnincreasen throughou tn thenbody. nThenincreasedn
hormonesnstmula tenphysicalnchanges. nFornexamplen thenadolescent growth spurtnnanrapidnnhormonallyn
