LAUSR

Peers are an important source of normative pressure in the context of adolescent risky behaviors, which is reflected in high behavioral homophily repeatedly found in adolescent groups. Two psychosocial mechanisms underlying this similarity have been identified: peer influence (or pressure) and peer selection (the process of befriending individuals similar to oneself). The two mechanisms have been explored primarily in the context of non-sexual adolescent risk taking (e.g., tobacco, alcohol and drug abuse). This study is the first longitudinal comparison of peer influence and peer selection in the context of female adolescents' sexual initiation. Using data from 162 female high-school students (Mage = 16 years, SD = 0.47) surveyed online twice in the period of 18 months, a cross-lagged path analysis pointed to a significant effect of peer influence, but not peer selection. Contrary to expectations, the moderating effect of peer conformism was not corroborated. This study’s findings confirm the importance of taking into account direct and indirect peer influence when designing comprehensive sexuality education programs.