The theory of planned behavior and binge drinking among undergraduate students: assessing the impact of habit strength.

The present study sought to apply the theory of planned behavior (TPB) to the prediction of binge drinking intentions and behavior among undergraduate students and to test whether habit strength explains additional variance in binge drinking behavior. Undergraduate students (N=137) completed measures of the TPB (i.e., attitude, subjective norm, self-efficacy, perceived control, and intention) and habit strength (Self-Report Habit Index) in relation to binge drinking. Frequency of binge drinking was assessed one month later (n=109). The TPB explained 75% of the variance in binge drinking intentions, with attitude and self-efficacy making significant contributions, and 35% of the variance in binge drinking behavior at one-month follow-up, with only intention making a significant contribution. Habit strength explained additional variance in binge drinking behavior (∆R(2)=.06), although intention remained as a significant predictor. The results suggest that binge drinking among undergraduate students is under the control of both intentional and habitual processes. Interventions to reduce binge drinking should therefore focus on the motivational determinants (e.g., perceived positive and negative consequences) of binge drinking as well as the environmental factors (i.e., contextual cues) that promote binge drinking.