If you’re at a bar and somebody starts a fight, what do you do? Root them on? Step in? Join the fight? Well, if one researcher’s findings are right, in about a third of these situations, someone would step in. It would probably be a man, and he’d probably intervene non-violently.

Michael Parks, a researcher at Penn State University, recently did a study to figure out just how often people take action when things get out of hand after a few rounds. He trained dozens of people to go out to bars and clubs in Toronto, watch for fights and to record what they saw. They looked for “aggressive incidents”—defined pretty broadly, as anything from a verbal insult to unwanted physical contact to all out brawling. All told the observers recorded 860 “aggressive incidents” over 503 nights in 87 bars and clubs.

What Parks found was that in just about one-third of these aggressive incidents somebody stepped in to break it up. Those who intervened tended to be men (80 precent) but the most frequent kind of aggression—men harassing women—was the least likely to see intervention. Previous research has looked into who starts fights at bars in the first place (that study was also conducted in Toronto, weirdly) and found that 77.5 percent of aggression was instigated by men. Women who were aggressive, the study found, were often reacting to unwanted sexual advances by men.

There were a few things that increased the likelihood of somebody stepping in—if the aggression was really severe and mutual, if it was between two males and if the participants were intoxicated. In other words, bystanders were more likely to get between two drunk dudes fighting each other than to get involved in any other altercation. Research Digest suggests that the pattern is likely explained by third parties assessing just how dangerous the situation might be. A man harassing a woman is less likely to escalate than two drunk dudes pushing each other around. Research Digest writes:

Taken together, Parks and his team believe their data show that third parties decide to intervene based on their assessment of the dangerousness of the situation. This fits with social psychology research showing that bystanders intervene more often in emergency situations that they perceive to be more dangerous. An alternative or parallel explanation is that third parties were influenced to intervene based on cultural rules around honour and saving face.

The researchers didn’t actually ask anybody who fought or intervened why they did so, so it’s hard to actually point to motives. But the classic bar room brawl—the type in which one guy punches another and suddenly the whole place is ripping each other apart—don’t seem to happen that often. In Toronto, at least.

More from Smithsonian.com:

The Johnson-Jeffries Fight

Muay Thai Fight