Peer network studies and interventions in adolescence.

Peer influence occurs across a wide variety of behavioral do-mains, which is an important reason for peer-led interventions:interventions in which peers are involved in the delivery of theprogram. These programs are promising in combatting unde-sirable behaviors (e.g. risk behavior) and promoting desirablebehavior (e.g. healthy lifestyle), but it was shown recently thatthe effectiveness of these programs is modest at best and themechanisms underlying programs’effectiveness are poorlyunderstood. Research is needed that promotes understandingof the relative, cumulative, and interactive impacts of differenttypes of peer relations and unpacks the various mechanismsunderlying peer selection and influence. This has the potentialto yield insights that advance theory and optimize peer-ledintervention