Behavioral contagion and official delinquency: epidemic course in adolescence

The cumulative onset curves for smoking, drinking, and sexual intercourse have been tracked through adolescence with reasonable success by recursive equations positing an "epidemic" or contagious process. The gist of these models is that the likelihood of onset in the next time period is proportional to the prevalence of the behavior among an adolescent's peers in the current time period. The present paper extends this approach to official delinquency. The fits to the data (from the Philadelphia cohort studies) are extremely tight. Several conceptual mismatches between the theory underlying the model and the model itself are discussed.