Modification Mechanisms of Descriptive Norm Perceptions Toward Vaping: The Role of Behavior Prevalence and Group Size in an Online Setting.

We often rely on descriptive norm perceptions as a mental shortcut for decision making. However, less is known about how such perceptions are shaped and modified by our experiences in day-to-day life. The interactive nature of the current media environment offers opportunities for individuals to access others' health behavior choices through online user-generated content. Within a setting of online comment boards, the current study examined the descriptive norm perception modification process toward vaping with a large-scale experiment that systematically varied levels of exposure to online commenters' vaping behavior choice indications. Findings revealed a significant positive effect of behavior prevalence on descriptive norm perceptions, which in turn were positively associated with vaping intention. This set of results was observed only when a sufficient total amount of comment exposures was ensured. The study provided empirical evidence for the underlying mechanism of the "quasi-statistical sense," which helps people draw conclusions about behavior prevalence and may influence their behavioral decision making. Theoretical and practical implications are discussed.