Alcohol consumption and the theory of planned behavior: An examination of the cognitive mediation of past behavior

This study examined the predictive power of the theory of planned behavior (TPB) in explaining alcohol consumption in 3 prospective samples of students (Ns = 178, 176, and 159). Generally, the TPB performed well, with attitudes subjective norms and perceived behavioral control (PBC) explaining between 28% and 40% of the variability in intentions. Intentions and PBC explained between 12% and 50% of the variability in behavior. Measures of self-identity as a "drinker" and past behavior contributed to predictions of intentions over and above the contribution of attitudes, subjective norms, and PBC. Measures of past behavior but not self-identity consistently contributed to predictions of behavior over and above the contributions from intentions and PBC. The direct relationship between past behavior and intention and between past behavior and behavior (independent of the TPB variables or self-identity) could not be attributed to common method variance.