Youth culture and smoking: Integrating social group processes and individual cognitive processes in a model of health-related behaviours.

This article assesses four theoretical models proposed to predict future smoking. Young adults were surveyed at three six-month intervals, the first occurring three months after leaving school. Models 1 and 2 were versions of theory of triadic influence (TTI), which links a person's behavioural experience and cognitions to their future behaviour. Model 1 did not fit the data; the fit of model 2 was just adequate. Model 3 combined TTI and self-categorization theory (ST), by allowing norms of the individual's peer group to influence cognitions and future behaviour. It fitted the data well. Model 4, which extended model, provided the best fit. Strength of identification to the peer group was found to enhance the effect of the peer group norm.