Shyness and susceptibility to social influence: Stronger concordance between norms and drinking among shy individuals.

Despite a large body of work exploring associations between perceived norms and drinking and norms-based interventions for drinking, less work has examined moderators of associations between norms and drinking outcomes to determine potential sub-groups that might benefit most from brief norms-based interventions. The present study investigates shyness as a moderator of associations between drinking norms and alcohol use. We hypothesized that shyness would moderate associations between drinking norms and alcohol use such that individuals who are higher in shyness might be more sensitive to social influence and thus show stronger associations between drinking norms and alcohol use. Participants included 250 college students (70% female; 44.5% White/Caucasian) aged 18-26 (M = 21.02, SD = 2.16) who met heavy drinking criteria (4/5 drinks on one or more occasions in the past month for women/men). Participants completed measures of demographics, shyness, alcohol use, alcohol-related problems, and drinking norms remotely at baseline and one-month follow-up (N = 169). Drinking norms were negatively associated with shyness and positively associated with baseline and follow-up drinking. Shyness was negatively associated with baseline drinking but not associated with follow-up drinking. Interaction models tested longitudinal associations between shyness, descriptive drinking norms, and follow-up drinking, controlling for baseline drinking and gender. Results showed that associations between drinking norms and drinks per week were strongest among people who were higher in shyness. Individuals who are shy may be more susceptible to social influence and thus may benefit more from a norms-based drinking intervention. Future work may explore shyness as a moderator of norms-based intervention efficacy.