Peers have often been hypothesized to play a central role in the development of externalizing problems. The extent to which an adolescent’s peers engage in antisocial behaviors is among the best predictors of whether they themselves engage in antisocial behavior (Pratt & Cullen, 2000). Moreover, these associations have been independently confirmed with respect to both aggressive (Capaldi et al., 2001) and delinquent (Vitaro et al., 2000) sub-dimensions of adolescent conduct problems, though to a lesser extent among the former, which represents a more overt form of externalizing behavior (Barnow et al., 2005).
