Self-Determination Theory as a Framework for Evaluating Within-Person Effects of Personalized Normative Feedback on Drinking


Academic consequences, alcohol use disorders, assaults, and death are real and present dangers for college students problematically consuming alcohol. A number of theories exist that aid in the understanding of problematic alcohol consumption. These theories have been used to create particularly effective interventions to reduce problematic alcohol consumption. Still, these interventions do not reduce problematic drinking for all people, all of the time. Through empirical and theoretical means, this work aimed to answer questions about why problematic alcohol consumption endures. Empirically, problematic alcohol consumption, its predictors, and interventions to reduce it were examined at the within-person level where the majority of variance resides. Theoretically, self-determination was employed to explain why people may be more or less inclined to drink following interventions both situationally and across situations. The present study tested the utility of within-person measurement and self-determination theory as moderators of a personalized normative feedback intervention and injunctive norms among heavy-drinking college students. Participants completed baseline assessments, received personalized normative feedback or a control intervention, completed daily assessments for 17 days, and completed a follow-up assessment. Analyses were conducted using structural equation modeling and multilevel modeling. Due to time constraints, the final intended sample of 300 participants was not successfully collected. Instead, 156 were included in the daily analyses, while 136 were included in the baseline-follow-up analyses. Results provided little compelling evidence of the moderating effect of self-determination on either a personalized normative feedback intervention or naturally occurring injunctive norms in predicting alcohol consumption. This lack of compelling evidence was largely due to an insufficient sample size to detect the effect sizes estimated by this study using conventional heuristics of statistical significance. The results do suggest that some of the most detectable interaction effect sizes may be at the within-person level, thus future research may benefit from focusing on within-person, as opposed to between-person effects. The effect sizes also suggest that the injunctive norms by self-determination interaction may be particularly fruitful for future research if future research confirms these findings in more powerful studies. Specifically, those that are less self-determined may be particularly susceptible to injunctive norms. Given past evidence of difficulty manipulating injunctive norms, this may suggest that altering people’s feelings of self-determination may be a useful route to reducing problematic alcohol consumption. Improvements for the study design are also suggested.



Self-determination theory, Alcohol, Personalized normative feedback, Injunctive norms, Motivation