Abstract: | This longitudinal project examined peer influence across five risk behaviors: cigarette smoking, alcohol consumption, marijuana use, tobacco chewing, and sexual debut. A total of 1,969 adolescents aged 12–18 years completed two waves of data collection. Each respondent matched behavior data for at least one friend. Results found that a random same sex peer predicts a teen's risk behavior initiation; there is influence only to initiate cigarette and marijuana use; and that there is influence to initiate and stop alcohol and chewing tobacco use. This finding suggests that friends may protect adolescents from risk activities. The study has implications for understanding how peer influence, expressed as social norms, may be used in public health campaigns that target teen behavior. |