For all outcomes the largest magnitude of influence came from friend smoking, but we are unable to determine if this is due to peer influence or peer selection (Madden et al. 2002). In a parallel study of offspring of drug dependent fathers, we found the largest risk for cannabis dependence was perceived friend cannabis use but peer smoking was not associated with cannabis abuse/dependence. Taken together, these two studies suggest some specificity for the environmental contribution to offspring substance use. Further research is warranted to determine the relative magnitude of peer drinking on offspring alcoholism.
