Available research has suggested that affiliation with prosocial peers reduces child and adolescent antisocial behavior. However, the etiologic mechanisms driving this association remain unclear. The current study sought to evaluate whether this association takes the form of a gene–environment interaction (G × E) in which prosocial peer affiliation acts to reduce the consequences of genetic risk for non-aggressive antisocial behavior during childhood.

Our sample consisted of 500 twin pairs aged 6–10 years from the Michigan State University Twin Registry (MSUTR).

The results robustly support moderation by prosocial peer affiliation. Genetic influences on non-aggressive antisocial behavior were observed to be several times larger in those with lower levels of prosocial peer affiliation than in those with higher levels of prosocial peer affiliation. This pattern of results persisted even after controlling for gene–environment correlations and deviant peer affiliation, and when restricting our analyses to those twins who shared all or nearly all of their friends.

Such findings not only suggest that prosocial peer affiliation moderates genetic influences on non-aggressive antisocial behaviors during childhood but also provide support for the theoretical notion that protective environmental experiences may exert their influence by promoting resilience to genetic risk.