Adolescents completed the Delinquent Behavior Inventory (DBI)14, a 36-item checklist of minor (e.g., “Skipping school”) and more serious (e.g., “Using a weapon in a fight”) delinquent behaviors (α = .89). Adolescents also completed two 8-item scales assessing the cognitive factors that underlie delinquent behavior: Aggressive Orientation (e.g., “If I didn't like someone, I might try to hurt him or her just for the heck of it,” α = .87) and Antisocial Attitudes (e.g., I see nothing wrong in trying a little beer with my friends,” α = .87). Finally, adolescent lifetime use (at least one time without parents' permission) of tobacco, alcohol, and marijuana was assessed via a private, computer-administered questionnaire. In our relatively young sample, lifetime use is best viewed as experimental use. Among those using substances in the last year, the modal response was less than once a month for each substance. The experimental use phenotype is especially appropriate for this age group in that research has consistently shown that substance use early in adolescence is a potent predictor of later substance misuse15-17.
