Genetic and environmental influences on early social competence: moderation by parental social support

This study examined whether social support available to parents moderated the heritability of parent-reported social approach at 12 months (N = 286 twin pairs, 52.00% female) and social competence at 30 months (N = 259 twin pairs, 53.30% female). Genetic and environmental covariance across age is also reported. Social support consistently moderated genetic influences on children’s social approach and competence, such that heritability was highest when parents reported low social support. Shared environment was not moderated by social support and explained continuity across age. Findings provide further evidence that genetic and environmental influences on development vary across context. When parents are supported, environmental influences on children’s social competence are larger, perhaps because support helps parents provide a broadly promotive environment.