This paper reports on the first longitudinal test of the Acquired Preparedness (AP) model of alcoholism risk, which holds that individual differences in key personality traits influence drinking behavior by influencing alcohol-related learning (Smith and Anderson, 2001). We studied 418 individuals making the transition to the independence of college across 3 longitudinal waves. Each of 2 longitudinal models predicting typical drinking quantity provided support for the AP process. In the first, drinking quantity at the end of the first year of college was predicted by positive urgency (the tendency to act rashly when experiencing extremely positive affect) at the start of college, and that predictive relationship appeared to have been mediated by expectancies that alcohol provides positive, arousing effects. In the second, drinking quantity was predicted by negative urgency (the tendency to act rashly when experiencing extremely negative affect) at the start of college, and that relationship appeared to have been mediated by the motive to drink alcohol to cope with subjective distress.