Emerging themes in preclinical research on alcohol and aggression

Animal research into the alcohol-aggression relationship is based on a need to understand this relationship in people, and its success depends on the degree to which animal models can provide appropriate parallels to relevant human phenomena. Comparisons of human and animal literature suggest that parallels may be found for the following: alcohol enhances aggression in some, but not all individuals; consumption increases the probability of victimization (being attacked by a conspecific); alcohol reduces anxiety, and socially stressed individuals show increased voluntary consumption; alcohol reduces avoidance of threatening situations or stimuli and may place individuals at greater risk of being attacked; both anxiety reduction and decreased avoidance of threat may increase the probability of involvement in violent situations. These findings suggest that a variety of mechanisms may be involved in alcohol enhancement of aggression. Differences in effects of alcohol on human, as opposed to animal, aggression may reflect specific human capabilities. Although high doses of alcohol consistently reduce aggression in laboratory animals, this may reflect motoric and sedative effects that are not relevant for human behavior, in which verbal aggression and aggression involving the use of weapons make motor capability less important. Human voluntary alcohol consumption may also reflect response to stressors that also simultaneously promote aggression, a situation not paralleled by animal studies in which the drug is administered rather than voluntarily consumed. Nonetheless, obtained parallels suggest that animal experimentation using ecologically relevant situations can provide highly generalizable analyses of the alcohol-aggression relationship.