The Role of Distal Variables in Behavior Change: Effects of Adolescents' Risk for Marijuana Use on Intention to Use Marijuana.

This study uses an integrative model of behavioral prediction as an account of adolescents' intention to use marijuana regularly. Adolescents' risk for using marijuana regularly is examined to test the theoretical assumption that distal variables affect intention indirectly. Risk affects intention indirectly if low-risk and high-risk adolescents differ on the strength with which beliefs about marijuana are held, or if they differ on the relative importance of predictors of intention. A model test confirmed that the effect of risk on intention is primarily indirect. Adolescents at low and high risk particularly differed in beliefs concerning social costs and costs to self-esteem. Not surprisingly, at-risk adolescents took a far more positive stand toward using marijuana regularly than did low-risk adolescents. On a practical level, the integrative model proved to be an effective tool for predicting intention to use marijuana, identifying key variables for interventions, and discriminating between target populations in terms of determinants of marijuana use.