title: Socioeconomic status modifies heritability of IQ in young children.
abstract: Scores on the Wechsler Intelligence Scale for Children were analyzed in a sample of 7-year-old twins from the National Collaborative Perinatal Project. A substantial proportion of the twins were raised in families living near or below the poverty level. Biometric analyses were conducted using models allowing for components attributable to the additive effects of genotype, shared environment, and nonshared environment to interact with socioeconomic status (SES) measured as a continuous variable. Results demonstrate that the proportions of IQ variance attributable to genes and environment vary nonlinearly with SES. The models suggest that in impoverished families, 60% of the variance in IQ is accounted for by the shared environment, and the contribution of genes is close to zero; in affluent families, the result is almost exactly the reverse.
authors: University of Virginia, Charlottesville 22904, USA. ent3c@virginia.edu
authors: Eric
authors: E
authors: Turkheimer
authors: Andreana
authors: A
authors: Haley
authors: Mary
authors: M
authors: Waldron
authors: Brian
authors: B
authors: D'Onofrio
authors: Irving I
authors: II
authors: Gottesman
mesh_terms: D001699:Biometry / Q000379:methods; D002675:Child, Preschool; D003072:Cognition Disorders / Q000453:epidemiology / Q000235:genetics*; D005500:Follow-Up Studies; D006801:Humans; D007360:Intelligence; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology