Abstract
OBJECTIVE: Perception of others' approval of alcohol use (i.e., injunctive drinking norms) is strongly predictive of alcohol use, particularly among young adults. Although between-person injunctive norms predict alcohol use, there is evidence of within-person fluctuations in the relationship between norms and drinking. The current study used ecological momentary assessment (EMA) to test within-person, day-level associations between injunctive norms and alcohol use and to test whether social context moderated this association. METHOD: Participants (n = 83, M age = 24.0 years, 50.9% female) completed a 2-week EMA protocol using a smartphone application. Injunctive norms, social context (type and gender of companions), and number of drinks consumed were assessed each morning following a drinking event. Multilevel models with repeated measures nested within participants tested main effects and interactions of between- and within-person injunctive norms, type of drinking companions, and gender of drinking companions on the number of drinks consumed. RESULTS: Day-level injunctive norms were positively associated with drinking quantity over and above baseline norms. The effect of norms differed by social context, such that norms were only positively related to drinking quantity when drinking with a friend or romantic partner (vs. drinking alone). The gender of friends with whom participants drank did not moderate the effect of norms on quantity. CONCLUSIONS: This study provides one of the first examinations of daily fluctuations in injunctive drinking norms. Because norms represent a malleable target for intervention, results offer new information regarding possible intervention targets.