Classroom norms and individual smoking behavior in middle school.

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.8–10 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 Given the addictive nature of smoking, the focus of public health efforts has been to prevent smoking among children.11–13 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. Peer influence may be the most significant social risk factor in adolescent experimentation with drugs such as tobacco; it is more powerful than parental influence.16–18 Keefe19 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 use, and cigarette use in particular, is well replicated.19–21 Peers have also been shown to have a greater influence on adolescent substance use than antismoking information from the media,26 which makes sense intuitively because peers are more proximal or immediate.16,23 This influence of peer smoking on the individual is robust, whether the adolescent is in middle or high school and whether he or she is a trier or an experimenter.16 Interestingly, peer smoking seems to change middle school students’ strong intentions not to smoke more than it increases levels of smoking intentions.24 There are several reasons that peer effects have a strong effect on adolescent smoking. First, adolescents tend to spend most of their time interacting with peers and tend to disengage from parents.25,26 Second, cigarette use has been found to represent a symbol of identification with a particular peer group, moreso than alcohol and marijuana.8 Third, repeated exposure to nicotine may lead adolescents to develop a more favorable sense of the tobacco smell, or addiction to nicotine via chemical reactions, which increases desire for cigarettes.3,27 Fourth, there is evidence for a “false consensus effect” in which adolescents overestimate peer acceptance for smoking as a social norm.28–30 Finally, in terms of self-selection, adolescents may choose to associate with their peers because this increases cigarette availability.21