Alcohol drinking and aggression are sometimes related. What’s not so clear is just why drunks sometimes become belligerent. What is it about being intoxicated that sometimes makes fighting seem like a good idea? And do all intoxicated people get more aggressive? Or does it depend on the circumstances? Actually, drinking alcohol sometimes reduces aggression.
The Theory

Psychologist Dr. Peter Giancola and student Michelle Corman explored these questions experimentally. One theory about alcohol and aggression is this. Intoxication impairs the part of the brain involved in allocating our limited mental resources. Specifically attention and working memory. The theory is this. Drunks can only focus on a reduced fraction of what’s going on around them. Thus, they narrow their social vision. They concentrate on provocative cues. At the same time, they ignore things that might have a calming effect.
The Study
The researchers tested this idea on a group of young men. Some of the men were given three to four alcoholic drinks before the experiment. Others stayed sober. Then the scientists had all of them compete against another person in a somewhat stressful game. It required very quick responses. Every time they lost a round, they received a shock varying in intensity. Likewise, when they won a round they gave their opponent a shock. The idea was to see how alcohol affected the men’s aggression. Researchers measured it by the shocks they gave..
But there was more. The investigators also manipulated some of the volunteers’ cognitive powers. They required them—some drinkers, some not—at the same time to do a difficult memory task. The idea was to see if they could distract those who were “under the influence” from their “hostile” situation. If they could tax their limited powers of concentration, perhaps they wouldn’t realize that someone was shocking them.
The Findings
And that’s exactly what happened. The intoxicated subjects who had nothing to distract them were aggressive towards their adversaries. But the intoxicated subjects whose attention was focused elsewhere were actually less aggressive than the sober non-drinkers. This seems counterintuitive. Yet it really isn’t. That’s because the sober men were cognitively intact. Therefore, they could pay attention to both provocations and distractions in the room. That resulted in lower levels of aggression.
It appears that intoxication has the potential to both increase and decrease aggression. It depends on where one’s attention is focused. The psychologists speculate that working memory is crucial. And not only to barroom behavior, but to all social behavior. That’s because it provides the capacity for self-reflection and planning. Activating working memory with non-hostile thoughts reduces the “brain space” available for inclinations towards violence.
Perhaps this knowledge could be used to end barroom brawls and domestic violence.
Resources for Alcohol Sometimes Reduces Aggression
Web ages
Alcohol Intoxication as a Cause of Speeding, Aggression and Sexual Misconduct.
Drinking Alcohol, Sex and Violence.
Alcohol Linked to Partner Violence.
Drinking Alcohol and Domestic Abuse.
Alcohol Consumption and Attitudes to Violence among College Students.
Source
Giancola, P. and Corman, M. Alcohol myopia and aggression. Psych Sci, in press.