Role of Alcohol and Sex Hormones on Human Aggressive Behavior

Abstract

The promoting role of alcohol on human aggressive behavior is well established. This action may relate to the fact that alcohol is commonly consumed in situations where aggression in also initiated for other reasons: the reduction in the capacity to cognitively control the behavior or comprehend the situational context, facilitation due to expectancy factors, and effects on steroid hormone levels and other biological structures. Positive associations have been reported between endogenous testosterone levels and both psychological and physical aggression in both men and women. Thus, possible effects of alcohol on testosterone levels are relevant for the expression of aggressive behavior. Recent investigations have demonstrated that alcohol may elevate testosterone levels in men, which may further affect aggressive behavior. In contrast, alcohol commonly elevates testosterone levels in women, especially during the use of oral contraceptives. This could have a major effect in promoting aggression in women under the influence of alcohol. Incomparisonto androgens, little is knownabout the role of estrogens inhumanaggressive behavior. Recently, however, a positive association was demonstrated between plasma estradiol and emotional negotiation during interpersonal conflict situations. Furthermore, a negative association was observed between estradiol and testosteronerelated physical, violent aggression inmen with a history of alcohol-related aggression. On the other hand, estradiol, rather than testosterone, was positively associated with psychological aggression in both control men and in men with alcohol-related aggression. The following conclusions may been drawn from the most recent studies: it seems that physical aggression itself is caused by factors other than testosterone but the underlying strength by which the aggression is expressed is related to testosterone. Furthermore, endogenous female sex hormones may be related to empathic behavior and could, thus, represent a counter-balancing factor in alcohol-related male aggressive behavior. Overall, recent findings imply that estradiol-testosterone-related regulations may not only explain individual differences in men but may also explain part of the broader gender differences regarding empathic and aggressive behavior.