It is important to emphasize that although adolescents may model the behaviors of distant peers and even media figures, the influence of close peers and friends appears to be stronger. In fact, even when adolescents imitate indirect social contacts, they do so mainly to impress their friends and maintain social circles (Payne & Cornwell, 2007). Thus, the context created by adolescents’ direct peers is doubly relevant. It is possible that families can influence affiliations with substance-using friends by monitoring their children’s activities and friendship choices, modeling behaviors and transmitting values that affect friendship choice, and structuring their children’s social contexts to increase access to prosocial peers. However, behavior genetic analyses suggest that adolescents select, or are selected by, friends in accordance with genetic variance. Applying a twin modeling approach to substance use scores constructed from nominated friends’ own reports, predicting 9th-grade alcohol use, Cleveland, Wiebe, and Rowe (2005) found that most of the variation (64%) in affiliations with substance-using friends was related to genetic variance, with the remainder (36%) explained by nonshared environmental factors.
