Spearman and the Theory of General Intelligence - Explorable

Statistically, g is a way to account for variance. This single factor has been shown to explain 40 - 50% of the variance in individual performance on IQ tests. Skiptomaincontent   Menu Search Home Overview Research Foundations Academic Self-Help WritePaper Quiz ForKids YourCode Login SignUp Menu Search Login SignUp Username:* Password:* SignupForgotpassword Leavethisfieldblank: Searchover500articlesonpsychology,science,andexperiments. Searchform Search: Leavethisfieldblank: Home Overview ResearchMethods Experiments Design Statistics FoundationsReasoning Philosophy Ethics History AcademicPsychology Biology Physics Medicine Anthropology Self-HelpSelf-Esteem Worry SocialAnxiety Sleep Anxiety WritePaper Quiz ForKids YourCode Home>Academic>Psychology>SpearmanandtheTheoryofGeneralIntelligence SpearmanandtheTheoryofGeneralIntelligence LyndsayTWilson29.1Kreads Theearly1900ssawCharlesSpearmanusingamathematicalapproachtothequestionofmeasuringhumanintelligence.UsingstatisticalfactoranalysisSpearmanidentifiedg,asingleunderlyingintelligencefactorhebelievedaccountedforthevarietyofobservableabilities. Spearmannoticedthatchildren’sgradesacrossallschoolsubjectstendedtobehighlycorrelated.Ifachilddidwellinonesubject,theygenerallyalsodidwellinanothersubject,andviceversa.Whatdidthissayaboutthenatureofintelligence?Hedevisedfactoranalysistomeasuretherelationshipsbetweenseeminglyvariedcognitiveabilitiesandaccountforthecorrelationshesawbetweenscoresondifferenttests.TheresultwasSpearman’stwo-factortheorywhichattemptedtoshowthatallcognitiveperformancecanbeexplainedbytwovariables:onegeneralability(g)andthemanyspecificabilities(s)itgaveriseto.Later,however,furtheranalysisshowedthatgalonewasenoughtoexplainthecorrelationsbetweendifferenttests.WhenpeopletalkaboutIQorintelligence,it’susuallythisgeneralmentalabilitythattheyarereferringto.Psychometrically,gasaconstructreferstotheoverallmentalcapacitybehindaperson’sperformanceonanynumberofcognitivetasks.Statistically,gisawaytoaccountforvariance.Thissinglefactorhasbeenshowntoexplain40-50%ofthevarianceinindividualperformanceonIQtests.Thisiswhyacompositescoreofmanydifferenttestsisassumedtogiveanestimationofg.Today,almostallIQtestsarefactormodelsinspiredbySpearman’sworkong.Asanexample,considertheStanford-Binettest,whichmeasuresdifferentareasofperformancethatcontributetogeneralintelligence,likeworkingmemoryandvisual-spatialreasoning.Todayintelligenceisusuallyunderstoodasahierarchy:smallerfactorsmanifestintheabilitytodohighlyspecifictasks,butthosefactorscanbearrangedintobroaderintermediarycategorieswhichinturnareencompassedwithinthemostgeneralfactor,g.AlternativesandCriticismsTheexistenceofasinglequantifiablefactorforhumanintelligencehasbeenhotlydebatedeversinceSpearmanproposedit.CriticismcamefromoneofSpearman’sownstudents,RaymondCattell,whothoughtthatintelligencecouldbeunderstoodastwomaincapacities:“fluid”(Gf)and“crystallized”(Gc).Cattellthoughtthatcrystallizedintelligencewasakindofcementedknowledgebankacquiredovertime,representingallthoseabilitiesthatwerealreadyfamiliarfrompreviouslearning.Ontheotherhand,fluidintelligencewastheabilitytoacquirethatknowledgeinthefirstplace,i.e.tolearninthemoment.HesawgasmoreaccuratelyGc,andthattestsfocusingonlyongwouldomitanimportantdevelopmentalfactorinhumanintelligence.Othersweresimilarlycriticalforthereductivenatureofg,includingpsychologistL.L.ThurstoneandJ.PGuilford.Bothbelievedthattherewereseveral,irreducibleandindependentdomainsofintelligence,howevermanyhavesincefoundcorrelationsbetweentheirtestswhichstronglysuggestageneralfactor.StillmorecriticismcamefromHowardGardenerwhoproposedninedomainsofintelligence,includingsomedecidedlynon-cognitiveoneslikemusical,existentialandbodily-kinestheticintelligence.Almosteveryonecanthinkofapersonwhoperformedpoorlyatschoolbutexcelledinsportordance,perhaps,orapersonwithmusicalgeniusthatdidn’ttranslatetoanyotherareaintheirlife.Gardnerarguedthattheacademicenvironmentover-emphasizedverbalandlogicalskillwhileignoringtheseotherformsofintelligence.However,hiscriticshaverespondedthatwethinkofsomethinglikeathleticskillasjustthat–askillandnotstrictlyintelligence.Currently,thegfactortheoryofintelligenceislargelyundisputedandhasbeenestablishedthroughexperimentalcognitiveresearch,brainanatomyandmoleculargenetics–whereithasalsobeenshowntohaveastrongheritablecomponent.Thoughitistakenastruethatthereisahighcorrelationbetweenperformanceondifferentskillstests,researchisstillunderwaytodeterminewhatcausesthatcorrelationandhow. Checkoutourquiz-pagewithtestsabout: Psychology101ScienceFlagsandCountriesCapitalsandCountries Fullreference: LyndsayTWilson(Nov21,2017).SpearmanandtheTheoryofGeneralIntelligence.RetrievedAug20,2022fromExplorable.com:https://explorable.com/spearman YouAreAllowedToCopyTheText ThetextinthisarticleislicensedundertheCreativeCommons-LicenseAttribution4.0International(CCBY4.0). Thismeansyou'refreetocopy,shareandadaptanyparts(orall)ofthetextinthearticle,aslongasyougiveappropriatecreditandprovidealink/referencetothispage. Thatisit.Youdon'tneedourpermissiontocopythearticle;justincludealink/referencebacktothispage.Youcanuseitfreely(withsomekindoflink),andwe'realsookaywithpeoplereprintinginpublicationslikebooks,blogs,newsletters,course-material,papers,wikipediaandpresentations(withclearattribution). Wanttostayuptodate?Followus! Follow@ExplorableMind Footerbottom LinksAboutFAQTermsPrivacyPolicyContactSiteMap CompleteCollection LikeExplorable?Takeitwithyouwhereveryougo. 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