It’s a well-established fact that drinking alcohol makes people more aggressive. For instance, 19 out of 20 acts of violence on a college campus involve alcohol consumption.

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This alcohol- link isn’t merely a correlation; alcohol has a causal effect on increasing aggression. Dominic Parrott, a psychological scientist at Georgia State University, has conducted many experiments showing the ability of alcohol to increase aggression. In one exemplary study, Dr. Parrott and his colleagues assigned a group of 136 male social-drinkers to drink either an beverage or a non-alcoholic control beverage. Males who consumed the alcoholic beverage administered greater shocks to an opponent than those who had consumed the non-alcoholic control. This is clear evidence that alcohol increases aggressive behavior.

But what if the opposite is also true? Could aggression increase the consumption of alcohol?

Some preliminary research suggests that this is the case. In a study of over 1,000 adolescents from high- neighborhoods, a ’s level of aggression predicted whether they consumed more alcohol in the next year. For example, more aggressive 14-year olds drank more alcohol at age 15 than their less-aggressive classmates. These data suggest that the relationship between alcohol and aggression isn’t a one-way street where alcohol only influences aggression. Instead, it’s likely that alcohol and aggression promote one other in a cyclic fashion.

Yet why would aggression increase how much alcohol people drink at a later time? We examined this possibility in a research study recently-published in the journal Aggressive Behavior.

We brought a sample of 24 social drinkers into our Magnetic Resonance Imaging (MRI) center. There, they completed an aggression task in our MRI scanner, in which they repeatedly chose how loud of a noise blast to administer to an opponent while we measured their brain activity. We replicated some of our past research, which showed that aggressive behavior is associated with greater activity in parts of the brain that promote the experience of reward and pleasure.

We then took the participants out of the MRI scanner and set four, frosty beers in front of them, informing them that they would now complete a taste test of the beers. The experimenter told them to drink as much of the beer as they would like and not to worry if they got drunk because they’d have to hang out in the lab for a while anyways. The beers were in fact non-alcoholic, but participants didn’t notice the difference until the experiment was over and we told them. We found that the more aggressive participants were in the MRI scanner (the louder they set the noises that blasted their opponent), the more beer they subsequently drank. These results were obtained from a small sample, but they provide preliminary evidence that aggressive behavior can predict greater alcohol consumption.

We also found that this link between aggression and subsequent alcohol consumption was explained by the extent to which participants exhibited activation in areas of the brain that are reliably linked to reward during the aggression act. This finding was observed even after we controlled for the influence of features such as . Thus, our study suggests a specific mechanism that links aggression to greater alcohol consumption: reward. The sweetness of may "bleed out" onto other behaviors such as drinking alcohol, rendering them more appealing than before the aggressive act. This specific reward-based brain mechanism may serve to reinforce the reciprocal bonds between aggression and alcohol consumption.

Indeed, the two-way street that flows between alcohol and aggression may be paved with the pleasure of both of these acts.