Differences in alcohol expectancy between aggressive and nonaggressive social drinkers.

Previous reports have shown that drinkers with aggressive personalities not only hold the strongest beliefs that alcohol facilitates aggressive behavior, but they also display the greatest increases in laboratory aggression after receiving alcohol. Given that several studies have demonstrated that a portion of the behavioral and subjective effects of alcohol are due to psychological expectancy, this study explored whether aggressive drinkers have elevated intoxication expectancies from laboratory beverages with unknown alcohol content. The rates of aggressive responses emitted in a money subtraction aggression model under baseline conditions were used to select an aggressive group and a nonaggressive group, each with five male and five female participants. Subjects then ingested and rated each of three placebo (1 ml alcohol) beverages administered hourly during a subsequent laboratory visit, and rated a series of three 0.35 g/kg of alcohol beverages the following day. Whereas nonaggressive subjects clearly discriminated the relative alcohol content of alcohol and placebo drinks, aggressive subjects gave progressively elevated shot equivalent ratings to placebo drinks, similar to their ratings of alcohol doses. However, despite similar self-reported drinking histories, aggressive subjects reported anticipating only half the intoxication from the alcohol doses (and in fact achieved a lower peak breath alcohol concentration) than was expected by nonaggressive subjects.