Although the effect sizes for the polygenic score X environment interactions were small, the pattern of effects is consistent with previous findings from the twin literature. Multiple independent twin studies find that parenting and peer environmental factors moderate latent genetic influences for alcohol use and related outcomes such that genetic influences increase under conditions of low parental knowledge and high peer deviance [6,7,8,9,48]. The convergence between the pattern of gene-environment interactions from twin studies and measured polygenic effects is encouraging, and suggests that polygenic approaches may be a useful way to characterize gene-environment interplay for aggregate genetic risk using measured genotypic data.
