Alcohol and human physical aggression: pharmacological versus expectancy effects.

OBJECTIVE Research has demonstrated that there is a relationship between alcohol consumption and aggressive behavior. Two basic theoretical positions have been proposed to account for this relationship: the pharmacological perspective and the expectancy perspective. This study examined these two competing explanations of the alcohol-aggression relationship. METHOD Subjects were 40 males selected from a pool of 233 potential subjects who were interviewed by telephone regarding their alcohol expectancies. Subjects who believed that alcohol increases their aggression and subjects who believed that alcohol decreases their aggression were selected to participate. These subjects were randomly assigned to one of two dose conditions: active-placebo or high dose of alcohol. Subjects were given the opportunity to behave in an aggressive manner within the context of a competitive reaction time task. Aggression was operationalized as the intensity of electric shock subjects set for their opponent during the task. RESULTS It was found that the high dose of alcohol resulted in significantly higher levels of aggression than the active-placebo dose regardless of subjects' alcohol-aggression expectancies. For the intoxicated subjects, the expectancy that alcohol increases aggressiveness tended to facilitate intense levels of aggression during conditions of high provocation. CONCLUSIONS The results suggest that the pharmacological effects of alcohol play a primary role in the relationship between alcohol ingestion and aggression.