The relative contribution of sibling deviance and peer deviance in the prediction of substance use across middle childhood.

This study investigated the quality of sibling relationships and sibling deviancy in a sample of children at-risk for substance use and antisocial behavior. Based on a history of empirical and theoretical models suggesting strong associations between children's development in the context of relationships and the emergence of delinquency and drug use, this research extends previous efforts by including sibling relationships in this developmental model, linking siblings with later substance use. Sibling relationship quality as well as peer deviance were examined using a multirater, multimethod assessment procedure. We tested 3 constructs (deviancy, warmth, and conflict) related to sibling behavior. Only sibling deviance and peer deviance directly predicted substance use. When both sibling deviance and peer deviance were examined as predictors of changes in substance use over time, only sibling deviance was significant. Implications for the development of substance use behavior in middle childhood are discussed.