The relationship between alcohol and aggression is well documented. Alchohol has been implicated in approximately 50% of violent crimes worldwide and crime statistics indicate that the prevalence of intoxicated aggression has increased steadily over the past 50 years. Alcohol consumption is strongly associated with a number of aggressive behaviours including violent threats, domestic violence, child abuse, sexual aggression, homicide and suicide. Three of the most well-accepted theories of alcohol-related aggression contend that alcohol facilitates aggression by (i) impairing anxiety and fear responses, (ii) disrupting higher-order cognitive functions important in maintaining people's inhibitions and (iii) increasing psychological and physiological arousal. Researchers in Kentucky looked at the first theory by studying 80 healthy male social drinkers between the ages of 21 and 33. The participants were divided into four groups. One group received alcohol plus a task designed to make them feel anxious, one group received a placebo plus the anxiety-inducing task, one group received alcohol and weren't made to feel anxious while a fourth group received a placebo and were not made anxious. (The anxiety-inducing task was to give a videotaped talk about what the participants liked and disliked about their bodies). Then the participants' levels of aggression were measured by getting them to play a game in which they could give electric shocks to an opponent that they thought was real but in fact was imaginary. The results showed that those people who had drunk alcohol but who had been made anxious were no more aggressive than their sober counterparts.
Phillips, Joshua P. and Giancola, Peter R. - Experimentally-induced anxiety attenuates alcohol-related aggression in men Experimental and Clinical Psychopharmacology February 2008, 16(1), 43-56