Alcohol Use Among American Youth: Differential Susceptibility to Peer Influence on Substance Use Tied to Genetic Risk

The behavior of peers is one of the most robust correlates of deviance and arguably the strongest influence on substance use; however, not all youth mirror their peers’ behavior. Understanding how youth may be differentially susceptible to peer influence has implications for both theory and substance use policy. The potential moderation of the peer behavior-youth substance use relationship by genetic risk is explored to determine if differential susceptibility to peer influence is partially tied to biological factors. A subsample of data from the first two waves of the National Longitudinal Study of Adolescent to Adult Health (Add Health) is utilized (n = 1,495). Evidence of a gene-environment interaction emerges whereby genetic risk conditions the relationship between peer substance use and early onset of alcohol use in models controlling for several risk and protective factors (e.g. poverty, self-control, victimization, social support, neighborhood dissatisfaction, religiosity). Genotype appears particularly salient when youth report a moderate degree of peer substance use (when peer substance use exceeds the mean but does not reach the extreme). This finding has implications for Burgess and Akers’ Social Learning Theory and other peer-based theories of behavior. It suggests that interventions to insulate youth from substance-using peers will be particularly impactful for those at enhanced genetic risk for early alcohol use. The identified gene-environment interaction partially explains why some youth are differentially susceptible to peer influence.