We examined whether attained socioeconomic status (SES) moderated genetic and environmental sources of individual differences in cognitive performance using pooled data from 9 adult twin studies. Prior work concerning SES moderation of cognitive performance has focused on rearing SES. The current adult sample of 12,196 individuals (aged 27-98…

Standardized mathematics test results of a twin sample during grades 3 and 6 were interpreted according to an interactional heredity x environment model. Results indicated that similar school instruction made monozygotic twins more alike but dizygotic twins less alike in mathematics knowledge. Social background effects were also studied. (SJL)

Genetic effects on specific cognitive abilities as distinct from those on general cognitive ability were studied in 302 pairs of twins (some reared together, some apart) from the Swedish Adoption/Twin Study of Aging. Overall, results showed significant genetic influence on specific abilities independent of influence on general ability. (SLD)

Swedish longitudinal studies of twins support Scarr-Salapatek's explanation of nature-nurture influences on intelligence. This model predicts more genetic variance in test results for advantaged than disadvantaged groups. Jensen's work, however, suggests equal amounts of variance among different social classes. (Author/CP)

This longitudinal study investigated hereditary and environmental influences on life situation, self-reported health, and coping ability at mid-life in relation to background factors collected during adolescence. A nationally representative Swedish sample comprised of monozygotic (MZ) and dizygotic (DZ) twins; a control group of singletons was…