Parents' and peers' normative influence on adolescents' smoking: results from a Swiss-Italian sample of middle schools students.

<bold>Background and Method: </bold>Adolescents observe and imitate people to whom they are associated in their social context, and the normative factors sent out by reference groups are crucial determinants of their decision to smoke. The aim of the study is to investigate how adolescents' smoking changes when they are exposed to factors of pro-smoking normative influence by parents and peers, and how age moderate this relation. A cross sectional survey collected data from 5657 students, aged between 11 and 14, from public and private middle schools in the Italian region of Switzerland (Ticino) on their smoking habits, perceived parents' and peers' approval and smoking.<bold>Results: </bold>Multinomial logistic regression show that, as adolescents get older, more of the pro-smoking factors come from peers and parents, the higher the risk gets of being a "heavy smoker" has compared against having no experience with smoking. Living in a context with no factor of normative influence toward smoking play a protective role against smoking, and this effect becomes more important than more harmful the smoking behavior in question is. Furthermore, peers' descriptive norms are more influential for adolescents to become "light" and "heavy smokers", while smoking being approved by peers is important for adolescents to become accustomed to smoking.<bold>Conclusions: </bold>Findings support the different influence of parents' and peers' norms on adolescents' smoking, and highlight the importance of peers' model behavior as the most important factor influencing smoking during adolescence. Such results have implications for programs that aim to prevent or reduce smoking in early adolescence when friendship choice starts to become crucial. [ABSTRACT FROM AUTHOR]