Using a multi-method, multi-reporter, longitudinal design, this study explored a social-contextual model of autonomy development and peer influence processes and was able to identify several factors that predicted the extent to which an adolescent's relative change in levels of substance use over a one-year period could be predicted by a close friend's level of use at baseline. As hypothesized, close friend use was a significant overall predictor of change in the target adolescent's use over this period. More importantly, though, a number of theoretically-predicted factors moderated this relationship, reflecting the broad impact of both contextual and individual factors linked to adolescent autonomy development in explaining peer influence processes. Results suggest that peer influence regarding adolescent substance use is maximized in social contexts in which adolescents approach autonomy issues from a relatively weak family base (lacking autonomy with their mothers and feeling less supported by their mothers); possess weak social skills in handling peer deviance, and are confronted with a peer who is well-liked within the broader peer group. Each of these findings, along with their limitations, is discussed in turn below.
