AbstractThis study examined multiple paths that can explain the co-occurrence of behaviors comprising a problem behavior syndrome in adolescence. Two hundred sixteen 15–18-year-olds in service programs for at-risk adolescents were assessed twice over a 6–12-month period to examine predictors of changes in levels of their delinquency, unprotected sexual intercourse, and use of soft and of hard drugs. This study considered (a) potential common predictors of multiple behaviors, (b) predictive links among behaviors over time, and (c) whether or not important unique aspects of individual behaviors remain in spite of their co-occurrence. Results were consistent with the hypothesis that the co-occurrence of problem behaviors results from multiple pathways of influence. The future occurrence of several problem behaviors was predicted by adolescents' initial negative expectations in social interactions. In addition, alcohol and marijuana use predicted increases in several other problem behaviors over time. Finally, individual problem behaviors retained important unique characteristics, suggesting the need for further research examining both their syndromal and unique aspects.
