Objectives-To investigate whether smoking prevalence in grade-level networks influences individual smoking, suggesting that peers are important social multipliers in teen smoking.Methods-We measured gender-specific, grade-level recent and life-time smoking among urban middle-school students who participated in Project Northland Chicago in a longitudinal cohort design.Results-Within schools, grade-level recent smoking had comparable effects on girls' and boys' individual-level smoking. Grade-level lifetime smoking had a greater effect on girls' smoking.
Conclusion-Interventions can target middle school classes and schools broadly, without making the identification of friendship networks a concern.Keywords social norms; smoking; middle school; gender Cigarette smoking is the leading cause of death in the United States; 1 these deaths are both premature and preventable. 2,3 Most adult smokers begin to smoke in adolescence. 4,5 By eighth grade, more than a quarter of US students have tried cigarettes, and by the end of high school, the percent who have tried smoking increases to more than half. 6,7 In fact, every day nearly 5500 youth under age 18 try cigarettes for the first time, and almost 3000 more become daily smokers. 3,8, Tobacco use also increases after school transitions, for example, the transition from middle to high school. [8][9][10] The pattern for initiation of cigarette use is the same as that seen for other drugs (alcohol and marijuana): use begins gradually in elementary and middle school, accelerates in late middle and high school, continues to increase during young adulthood, and gradually stabilizes or decreases in middle adulthood. 8 Contact Dr Brown, h.shelton.brown@uth.tmc.edu. Given the addictive nature of smoking, the focus of public health efforts has been to prevent smoking among children. [11][12][13] Recent research on health behaviors and peer influence, particularly in the area of obesity, has offered a hopeful sign: perhaps peer group effects, 14 which partly cause poor health behavior, can also improve health behavior. If influential persons within peer groups change behavior, this may lead others in the peer group to improve behavior, even if they themselves are not a direct target of the intervention. The ripple effects of changes in health behaviors carrying over to others is known as a social multiplier. 15 The existence of social multipliers means that scarce prevention resources could conceivably be concentrated on smokers or potential smokers rather than spreading resources more thinly across all children, who may or may not be at specific risk for smoking.
NIH Public AccessPeer influence may be the most significant social risk factor in adolescent experimentation with drugs such as tobacco; it is more powerful than parental influence. [16][17][18] Keefe 19 showed that as youth age, parental influence on substance use decreases, but peer influence remains strong and consistent. The result that peers are more influential than parents in predicting adolescent substance...