The theory of planned behavior and binge drinking: assessing the impact of binge drinker prototypes.

The present study assessed the value of including prototype perceptions within the theory of planned behavior (TPB) when predicting young people's binge drinking intentions and behavior. Undergraduate students (N=94) completed questionnaires assessing the main constructs of the TPB as well as measures of prototype evaluation and prototype similarity. Binge drinking behavior was assessed at one-week follow-up (N=79). The TPB explained 58% of the variance in binge drinking intentions and 22% of the variance in binge drinking at one-week follow-up. The prototype perception measures explained additional variance in both binge drinking intentions (DeltaR(2)=.04) and behavior (DeltaR(2)=.09), although only prototype similarity emerged as a significant predictor. In addition, a significant interaction was found between prototype similarity and subjective norm in relation to the prediction of binge drinking behavior, suggesting that the perception of supportive norms may enhance the impact of prototype perceptions on health-risk behavior. The implications of the findings for interventions to encourage more appropriate drinking behavior are outlined.