Three key questions were addressed in this study:
1.
Do friends' models of conventional behaviour, positive orientation to health, positive orientation to school, religiosity, intolerant attitudes toward deviance, and regulatory self-efficacy constitute factors that protect Italian adolescents against multiple risk behaviours?
2.
Do these same variables serve as protective factors that buffer adolescents from negative influences of peer deviance in a longitudinal model?
3.
Do protective factors modify the influence of peer deviance in the same way among boys and girls and among younger and older adolescents