title: The heritability of general cognitive ability increases linearly from childhood to young adulthood.
abstract: Although common sense suggests that environmental influences increasingly account for individual differences in behavior as experiences accumulate during the course of life, this hypothesis has not previously been tested, in part because of the large sample sizes needed for an adequately powered analysis. Here we show for general cognitive ability that, to the contrary, genetic influence increases with age. The heritability of general cognitive ability increases significantly and linearly from 41% in childhood (9 years) to 55% in adolescence (12 years) and to 66% in young adulthood (17 years) in a sample of 11 000 pairs of twins from four countries, a larger sample than all previous studies combined. In addition to its far-reaching implications for neuroscience and molecular genetics, this finding suggests new ways of thinking about the interface between nature and nurture during the school years. Why, despite life's 'slings and arrows of outrageous fortune', do genetically driven differences increasingly account for differences in general cognitive ability? We suggest that the answer lies with genotype-environment correlation: as children grow up, they increasingly select, modify and even create their own experiences in part based on their genetic propensities.
authors.affiliation: Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, UK.
authors.forename: C M A
authors.initials: CM
authors.lastname: Haworth
authors.forename: M J
authors.initials: MJ
authors.lastname: Wright
authors.forename: M
authors.initials: M
authors.lastname: Luciano
authors.forename: N G
authors.initials: NG
authors.lastname: Martin
authors.forename: E J C
authors.initials: EJ
authors.lastname: de Geus
authors.forename: C E M
authors.initials: CE
authors.lastname: van Beijsterveldt
authors.forename: M
authors.initials: M
authors.lastname: Bartels
authors.forename: D
authors.initials: D
authors.lastname: Posthuma
authors.forename: D I
authors.initials: DI
authors.lastname: Boomsma
authors.forename: O S P
authors.initials: OS
authors.lastname: Davis
authors.forename: Y
authors.initials: Y
authors.lastname: Kovas
authors.forename: R P
authors.initials: RP
authors.lastname: Corley
authors.forename: J C
authors.initials: JC
authors.lastname: Defries
authors.forename: J K
authors.initials: JK
authors.lastname: Hewitt
authors.forename: R K
authors.initials: RK
authors.lastname: Olson
authors.forename: S-A
authors.initials: SA
authors.lastname: Rhea
authors.forename: S J
authors.initials: SJ
authors.lastname: Wadsworth
authors.forename: W G
authors.initials: WG
authors.lastname: Iacono
authors.forename: M
authors.initials: M
authors.lastname: McGue
authors.forename: L A
authors.initials: LA
authors.lastname: Thompson
authors.forename: S A
authors.initials: SA
authors.lastname: Hart
authors.forename: S A
authors.initials: SA
authors.lastname: Petrill
authors.forename: D
authors.initials: D
authors.lastname: Lubinski
authors.forename: R
authors.initials: R
authors.lastname: Plomin
mesh_terms: D000293:Adolescent; D041923:Adolescent Development / Q000502:physiology*; D000328:Adult; D000375:Aging / Q000235:genetics*; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D019655:Quantitative Trait, Heritable; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D014481:United States