The night is going smoothly. You’re out at the bar with your friends having a great time. Then, all of a sudden, a fight breaks out. It’s the same friend every time. He’s wildly punching another of your friends. Or the guy standing behind him. Or the waiter. Or the bouncer. Or a lamp post.
So goes a night with an angry drunk.
According to this study, which cropped up in every Facebook feed over the summer, you’re dealing with a “Mr. Hyde,” one of four scientifically determined drinking personalities (the others being “Hemingway,” “Mary Poppins” and “the Nutty Professor”).
But what exactly turns your pal Jekyll into an aggressive asshole when he drinks?
David Friedman, a professor of physiology and pharmacology at the Wake Forest University School of Medicine, who has been conducting drug-abuse research for nearly 40 years, says it’s a question that can have a deceptively simple answer. “You probably won’t be surprised to hear this, but some people are just angrier or more hostile than others,” Friedman explains. “And it’s the angry folks who get angriest when they’re drunk.”
Obvious as it may be, it still took years of research to prove scientifically. It’s also not that cut-and-dried. The reason for the booze-fueled Jekyll-to-Hyde transformation is actually trifold: a mix of personality, neuroscience and social context. So yes, it doesn’t help if you’re constantly pissed off when you’re sober, but how your brain deals with your buzz and the time and place you’re buzzing are equally important.
Reason #1: Personality Type
Even the obvious isn’t all that obvious. That is, screamers aren’t the only angry drunks. If you silently seethe, you’re also liable to turn nasty when you drink. A 2010 study conducted by the Swedish Institute for Social Research found a link between people who regularly suppress their anger and an increased likelihood of getting into drunken brawls. The researchers noted that because alcohol decreases our self-control, those with pent-up rage are more likely to have it come out when they’re drunk. The other interesting finding from the study was that those who suppressed their anger were more likely to drink to the point of drunkenness, which subsequently led to more violent incidents. This wasn’t the case for those who didn’t regularly suppress their anger.
That said, those who experience frequent rage — whether externally or internally—aren’t the only ones prone to drunken outbursts. A 2011 study led by Brad Bushman, a professor of communication and psychology at Ohio State University, found that those who focus more on the present than the future are generally more aggressive when sober, a trait that’s compounded when they drink. They already have difficulty thinking about the future and the consequences of their actions, and alcohol makes their short-sightedness more extreme.
“Alcohol has a myopic effect,” Bushman said in a release about the study. “It narrows your attention to what’s important to you right now. That may be dangerous to someone who already has that tendency to ignore the future consequences of their actions and who is placed in a hostile situation.”
Reason #2: Neuroscience
“Alcohol affects almost all the chemical systems in the brain,” Friedman says. Among those impacted are two neurotransmitters that cells use to communicate with each other. A few drinks can short-circuit this conversation and result in parts of your brain not talking to each other as much as they should.
The lack of communication is toughest on the prefrontal cortex, the epicenter for decision-making, judgment and generally making sure you don’t make an ass of yourself. “Us humans are typically driven by our wants and needs, and we tend to be impulsive,” Friedman says. “Without that prefrontal cortex, the lower parts of our brain that are full of wants and needs go unchecked. It’s the adult in the room, and as such, it can perceive the consequences of our actions. But when we’re drinking, the prefrontal cortex isn’t able to exert its influence as effectively. So if you take someone who is more prone to anger in general, they might be less likely to restrain it when drinking.”
Alcohol also messes with serotonin, which plays a big role in regulating your mood, among other things. Friedman notes that people with naturally lower levels of serotonin tend to be more violent. “And drinking alcohol decreases serotonin levels even further,” he explains. The math from there gets pretty easy — naturally low serotonin plus serotonin-depleting alcohol equals a high probability for violent outbursts.
Reason #3: Social Situations and Context
Because we’re social creatures, how we interpret social cues can make us feel a certain way about a person and greatly influence how we act around them. Those cues, however, can go to shit when we’re drinking. “Alcohol makes it harder for people to interpret facial expressions, which is a complex thing to do,” Friedman says. “It’s particularly difficult to distinguish threatening from submissive when under the influence. So here you are, you’re a little bit angry to begin with because that’s your nature, your self-control is weakened [by alcohol] and you look at the guy at the other end of the bar, and what may be a neutral or nonthreatening face suddenly becomes threatening. Then you act out.”
And that’s why the same guy is always throwing the same punches every time you go out drinking together.
“There’s a saying that the best way to predict future behavior is to look at past behavior,” Friedman says. “If someone has been an angry drunk in the past, you can anticipate they’ll be again sometime in the future. So maybe you should consider dropping them from your guest list.”
