Mechanisms of Social Media Effects on Attitudes Toward E-Cigarette Use: Motivations, Mediators, and Moderators in a National Survey of Adolescents

Background: Exposure to risk behavior on social media is associated with risk behavior tendencies among adolescents, but research on the mechanisms underlying the effects of social media exposure is sparse. Objective: This study aimed to investigate the motivations of social media use and the mediating and moderating mechanisms of their effects on attitude toward electronic cigarette (e-cigarette) use among adolescents. Methods: Using data from a national sample survey of adolescents (age=14-17 years, N=594), we developed and validated a social media use motivation scale. We examined the roles of motivations in the effect of social media use on risk exposure and risk attitude. Results: Motivations for social media use included agency, self-expression, realism, social learning, social comparison, and filter. These motivations were associated differentially with the frequency of use of Facebook, Instagram, Snapchat, and YouTube. Frequency of social media use was positively associated with exposure to e-cigarette messages across the four platforms (Ps<.001). Exposure to e-cigarette messages on Instagram (P=.005) and Snapchat (P=.03) was positively associated with attitude toward e-cigarette use. Perceived social media realism moderated the effects of e-cigarette message exposure such that when realism was high, the exposure effect was amplified, but when realism was low, the effect was mitigated (P<.001). A three-way interaction effect (P=.02) among exposure, social learning motivation, and social norm on attitude toward e-cigarette use was found. When perceived social norm was high, the moderating effect of social learning motivation on e-cigarette use attitude was amplified, but when social norm was low, the social learning motivation effect was attenuated. Conclusions: Because perceived social media realism moderates the effect of exposure to e-cigarette messages on attitude toward e-cigarette use, future intervention efforts should address the realism perceptions. The three-way interaction among exposure, social learning motivation, and social norm indicates the importance of addressing both the online and offline social environments of adolescents. The social media use motivation scale, reflecting perceived affordances, is broadly applicable. Understanding social media use motivations is important, as they indirectly influence attitude toward e-cigarette use via frequency of social media use and/or frequency of exposure to e-cigarette messages on social media.