This study is the first to demonstrate that smoking in movies is associated with smoking in young adults in a dose-dependent manner; the more a young adult is exposed to smoking in the movies, the more likely he/she will have smoked in the past 30 days or have become an established smoker. These results are similar to prior studies demonstrating the effect smoking in the movies has on smoking initiation in adolescents.3,5–8,13,41–43
Exposure to smoking at the highest quartile corresponded to an AOR of 1.77 (1.213
) for 30-day young adult smoking. Previous studies on adolescents reported a strong effect of exposure on smoking initiation, 2.5013
(95% CI=1.7–3.5) to 2.718
(95% CI=1.7–3.50) for the highest quartile of movie exposure. The effect in young adults is probably smaller than in adolescents for two reasons. First, about two thirds of ever smokers are current smokers by the time they reach their 18th birthday, so many of the young people who are affected by smoking in the movies will have started smoking by the time they reach age 18, leaving fewer people susceptible to starting smoking because of exposure to smoking in movies. Second, studies on adolescents focused on smoking initiation (Have you ever tried smoking a cigarette, even just a puff?), not current or established smoking, because smoking is infrequent among adolescents7
and not all initiators go on to become current or established smokers. Since most young adults will have smoked a few puffs of a cigarette during adolescence, ever smoking a single puff (initiation) is not an appropriate behavior to study smoking behavior in young adults. The current study on young adults used the most analogous behavior for adolescent initiation: current and established smoking.
Even though the effect demonstrated in young adults is smaller than effects shown in adolescents, the magnitude of the effect of smoking in the movies is comparable to other environmental risk factors for smoking initiation in young adults. For example, tobacco company advertising in bars, clubs, or college campus social events increases the odds of 30-day young adult smoking by a factor of 1.75 (95% CI=1.47–2.08),44
similar to the effect of exposure to smoking in the movies at the highest quartile (odds ratio=1.77).
The effect of smoking in the movies on smoking behavior is direct with 30-day smoking and indirect with established smoking. The finding that smoking in the movies is related to recent 30-day smoking suggests that movies may primarily influence young adult smoking by recruiting new smokers. Rather than directly encouraging young adults to smoke frequently, smoking in the movies may instead encourage young adults to experiment with smoking. Once experimentation occurs, other factors become influential in encouraging smoking. As indicates, exposure to friends and relatives who smoke and having positive expectations for smoking—both of which increase with increased exposure to smoking in movies—increase the probability of established smoking. These effects persist even after controlling for a wide variety of other variables, including the effects of cigarette advertising. This model is supported by psychological literature on social learning, modeling, and imitation that suggest that much of behavior is learned by observing others, including those shown on screen.14,45,46