Social drinking history, behavioral tolerance and the expectation of alcohol

This research tested the hypothesis that a compensatory response to cues for alcohol contributes to the greater behavioral tolerance displayed by more experienced social drinkers. Sixty male social drinkers, ranging from 19 to 24 years of age, participated in the study. Thirty subjects had been drinking for 20 months or less (mean = 11.0 months), and were classified as novice (N) drinkers. The remaining 30 subjects had been drinking for 24 months or more (mean = 40.8 months), and were classified as experienced (E) drinkers. All subjects practiced a pursuit rotor task that measured psychomotor skill. Equal numbers of E and N subjects were then assigned to one of three groups (n = 10). Two groups were led to expect alcohol and performed the task after receiving either 0.56 g/kg alcohol, or a placebo. The third group received no beverage. E subjects displayed more behavioral tolerance to alcohol than did N drinkers. In accord with the hypothesis, E drinkers displayed a drug-opposite improvement in performance under a placebo, whereas N drinkers showed no appreciable change in performance. These observations support the hypothesis that the acquisition of a compensatory response to cues predicting the administration of alcohol contributes to the greater behavioral tolerance of more experienced drinkers.