We all know that drinking alcohol changes the way people think and can make them act strangely right? We also know that alcohol is involved in more than 50% of violent crimes and about 75% of partner violence. The question is, why the connection?

A recent paper I published suggests that drugs and alcohol can not themselves be thought to cause violence. Still, the relationship exists, so what gives?

(Before you go any further, if you’re unclear about the difference between causation and association, I suggest you read this article)

Your brain and alcohol abuse

The thought altering effects of consuming alcohol, and most drugs, can be said to affect something called executive functioning (EF). What exactly makes up this type of functioning is a source of some debate, but let’s just say that it refers to attention, strategic planning, reasoning, thought flexibility, and the ability to process information in working memory (an important type of memory used in learning).

You can probably already tell that this type of brain function is extremely important and that different people possess different levels of it. I can also tell you that alcohol consumption has  been shown to reduce overall executive functioning. If you drink alcohol, or have ever seen someone drink, this probably doesn’t come as a huge surprise.

The thing is that alcohol consumption messes up everyone’s EF, though obviously, the more you drink, the more affected you become. Still, given the fact that more than 50% of Americans report at least one binge drinking episode a year and less than 7% are involved in violent crime, something else must be at play, right?

Aggressive personality and irritability

As I mentioned earlier, I published a paper showing that aggressive personality, which I measured using 5 different tests, contributes far more to violent behavior than drug use alone. Still, a recent study found that irritability alone could account for some aggressive behavior. Still, the more interesting finding had to do with alcohol-related EF problems and irritability together. The experiment was pretty interesting, so let’s go over it for a bit.

Researchers at the University of Kentucky took more than 300 students and gave them a whole bunch of tests assessing their EF and their overall level of irritability. Afterward, half of the students were given alcohol to drink (about 3-4 drinks per person) and the other half was given a similar number of drinks that contained no alcohol but were sprayed before being handed to smell the same. The students were then asked to play a game that pitted them against another person. The secret was that there was no game and no other person, the winner and loser in each round was pre-determined. Every time the student “won” they got to give the other player a shock, but every time they lost, they themselves got shocked. As the game went on, the shocks the participants got increased in intensity. The researchers wanted to see how the students would react and how large the shocks they would give back would be.

The results showed that the more mistakes people made in their initial EF testing (and therefore the less overall EF capability they showed) the more aggressive they were. This makes sense, as people who are less able to plan, think ahead, and control their behavior would be more likely to engage in things that would hurt them, or misjudge events and think react inappropriately. Irritability was also shown to affect aggression, but this time only for men and intoxicated women.

The effect of alcohol abuse on aggression and violence

When the whole thing was put together the researchers found that for drunk men only, reduced EF and increased irritability worked together to generate even more aggression that was shown for all the other participants. For the simplest example think back to anyone you know who is pretty quick to react anyway and is a little too easily pissed-off. Chances are they become a pretty mean drunk who likes to get in fights.

Obviously this makes sense if you know someone like that, but in terms of helping us make decisions about who should be considered dangerous and who shouldn’t, especially when consuming alcohol, this research helps further explain why we see such a strong connection between alcohol abuse and violence or aggression.

The way I see it there’s a relatively small number of people (mostly men) who is normally pretty aggressive, irritable, and lacking in judgment and self-control, who often get violent when they drink alcohol. For them, many alcohol drinking episodes end badly, and since they’re the most visible of the aggressive drinkers, their behavior produces an association between alcohol consumption per se and violence. For the rest of us, alcohol consumption rarely leads to violence, but violence rarely occurs without drinking alcohol either, so we hardly ever enter the equation at all. That’s why the pattern holds.

Citations:

Godlaski, A. J., Giancola, P. R. (2009). Executive function, Irritability, and Alcohol-Related Aggression. Psychology of Addictive Behavior, 23, 391-404.

Jaffe, A. et al., (2009). Drug Use, Personality and Partner Violence: A Model of Separate, Additive, Contributions in an Active Drug User Sample. The Open Addiction Journal, 2.