PSYCHOLOGICAL SCIENCE i Research Article ASSOCIATIONS BETWEEN COGNITIVE ABILITIES AND SCHOLASTIC ACHIEVEMENT: Genetic Overlap but Environmental Differences

Abstract-Little is known about the genetic and environmental etiology of the association between specific cognitive abilities and scholastic acfiievenient diwittg the early school years. A niirltivariate genetic analysis of cognitive and achievement measirres was condircted for 146 pairs of identical twins and 132 pairs of fraternal twins from 6 to 12 years of age. At the phe-notypic level, measirres of achievement were moderately cor-related with specific cognitive abilities. A mirltivariate model inchding one general firctor and specisc factors in the genetic nnd environmental matrices indicated that the phenotypic re-lationship between achievement and cognition was mediated primarily by genetic ittflrtences. Genetic correlations among the cognitive and achievement tests ranged from.57 to.85, shared environment correlations were essentially zero. and specific en-vironment correlations were low (.OO to.19). We conclude tha