Ohio State study sheds light on the link between alcohol and aggression

COLUMBUS, Ohio (WCMH) -- Researchers say it's a known fact that alcohol increases aggressive behavior and numbs pain, but why? A first-of-its-kind study conducted at The Ohio State University helps people better understand that link.

The simple answer researchers found is that intoxicated people lack empathy, causing them to care much less about harming themselves or others. Brad Bushman, professor of communication at Ohio State, said this study was conducted over several years, with two independent experiments and more than 700 test subjects. 

He said not being able to feel your pain and the pain of others can be dangerous, and that's what he and other researchers found to be the link between alcohol and aggression.  

“When you numb the pain, you just don't care about things,” Bushman said.

Their study was published in the Journal of Studies on Alcohol and Drugs. Bushman said they found participants using newspaper ads, leading to 543 participants in one study and 327 in the other. He said all participants described themselves as 'social drinkers,' meaning they have three or four drinks at a time around once a month.

“We randomly assigned people to consume either an alcoholic beverage or placebo beverage. The placebo beverage looked like alcohol, tasted like alcohol, smelled like alcohol," Bushman said.

He said they were all around the .01% blood alcohol level. He said after they drank their beverage each person received an electrical shock to two of their fingers.

“We started at a very low level that they could barely feel. And then we turned up until it became a level they described as painful. That was the pain threshold. And so that was level 10 shock, and then level nine shock was 95% of that and so on,” Bushman said. 

He said next those subjects competed against an opponent who was actually an accomplice from the experiment on a task. Researchers randomly declared a participant a winner and that winner got to pick what level of pain the loser is shocked and how long the pain lasts. 

“What we found is that people who are intoxicated could tolerate more pain. They had a higher pain threshold. They were more numb to the pain, and they were also more aggressive," Bushman said. “They don't care. And so when you can't feel your own pain, you apparently don't care about inflicting pain on others as much.”

Columbus Police data shows they have responded to dozens of shootings at bars and clubs so far this year. When NBC4 spoke with Columbus Police Deputy Chief Smith Weir earlier this year about the city’s 100th homicide, he said alcohol is often a factor in violence.

“As the night gets longer and as people might engage in more drinking or more using whatever substance that they're using, sometimes their judgment gets impaired," Weir said. "Sometimes their ability to cope with adversity or any kind of opposition is impaired and that leads to violence.”

Bushman said this study sheds light on why this occurs.

“In society, we want people to feel empathy for others," Bushman said. "That's a good thing, to feel empathy for others, and alcohol reduces that, which is not a good thing."

So far this year, Columbus Police data shows there have been five fatal shootings at bars and clubs and four fatal shootings at what they call after hours clubs. Police say alcohol is often linked to domestic violence, too.