Abstract

Undergraduate students engage in risky alcohol use; this includes heavy drinking and drinking that leads to problems. The theory of planned behaviour and reasoned action approach identify injunctive norms – perceived approval of drinking behaviour – as central in predicting risky drinking. However, research linking injunctive norms and risky drinking has provided mixed support, thereby contributing to a possible under-utilization of injunctive norms in interventions. The unclear association of injunctive norms and risky drinking may be a result of extensive variability in the operationalization of injunctive norms and the utilization of injunctive norms measures that have poor psychometric properties. The first aim of this research is to improve the measurement of injunctive norms via the development of an injunctive norms measure in undergraduates. The second aim is to utilize this measure to investigate the social anxiety risk pathway to alcohol-related problems in undergraduates. In the first study, using best practices in scale construction, we developed and validated the Perceived Approval of Risky Drinking Inventory (PARDI), which assesses perceived friend, parent, and typical student approval of four risky drinking domains: heavy drinking, drinking-related problems, coping-related drinking, and sexual-risk taking. Psychometric evaluation indicated satisfactory scale score and composite reliability, support for convergent validity, and invariance across gender and drinking status. Utilization of the PARDI may allow researchers to ask more nuanced questions pertaining to undergraduate risky drinking aetiology. In the second study, we investigated the effect of social anxiety and injunctive norms (perceived friend approval of drinking-related problems) on undergraduate alcohol-related problems. Undergraduates completed assessments of injunctive norms, social anxiety, and alcohol-related problems every four months for one year. Controlling for age and sex, higher participant injunctive norms were positively associated with alcohol-related problems (between-subjects analysis) and when injunctive norms were elevated in comparison to participants’ own means, there was a concurrent elevation in alcohol-related problems (within-subjects analysis). Age, but not sex or social anxiety, moderated the within-person association: within-person injunctive norms was more strongly related to alcohol-related problems as age increased, suggesting that injunctive norms exert an increasing influence on risky drinking as students progress through university.