Differential environmental influences on the development of cognitive abilities during childhood

Abstract

Twin studies have shown strong evidence that cognitive abilities are heritable. This longitudinal study examines genetic and environmental influences on distinct developmental patterns of verbal and non-verbal cognitive abilities from age 7 to 12 in 4718 British twins. Six subgroups with distinct patterns were identified with comparable heritabilities of group membership (ranging 0.37–0.62). Non-shared environmental influences that differentiate family members on group membership appear to be particularly strong in the three subgroups that demonstrated substantial developmental mean changes of cognitive abilities (ranging 0.51–0.54), compared to the other three subgroups with relatively stable mean levels (ranging 0.29–0.34). Shared environmental influences making family members similar for group membership were significant in only two subgroups – among the children with continuously low scores (0.20) and developmental early starters (0.28). These results suggest the existence of distinct developmental patterns of cognitive abilities. The impact of shared and non-shared environment on the membership of different developmental patterns may be greater for some children than others.