“There’s a new focus, especially on college campuses, on studying bystander intervention in preventing sexual violence,” says psychology professor Dominic Parrott, director of Georgia State University’s Center for Research on Interpersonal Violence. “This was a chance to see what people do to intervene and what actually works. Our experiment allowed us to see what happens and why.”

In the study in Sexual Abuse, pairs of young men who were friends discussed whether to show sexually explicit images to a young woman who did not wish to see the images. Some of the men consumed alcohol and others did not. Researchers then observed how some of the men successfully persuaded their peer to refrain from showing the offensive images.

The findings indicate that men who had confidence in their ability to intervene tended to make statements that recognized the young woman’s wishes and appealed to a shared sense of morality. These statements were critical to the young men’s ability to convince their friend to refrain from showing the offensive images, the researchers say.

“The most effective arguments were based in a pro-social morality—statements like ‘That’s just not the right thing to do.’ Statements of objective consideration—like, ‘We should do as she asks’—were also effective,” Parrott says.

“There was a lot of talk among the peers in the experiment and not all of it was pro-social statements. But we saw that nothing except these pro-social arguments was effective in stopping this simulated sexual violence in the lab.”

When men in the study used statements based on gender stereotypes, they were less effective in persuading their peers, Parrott says. These less effective statements included: “She seems like a nice girl, so I picked the non-sexually-explicit video.”

Parrott says he hopes the study will advance the discussion of how bystanders can help prevent sexual violence against women by illustrating what has shown to work.

“The implication,” he says, “is if you are in a situation and you see something happening, whether it is misogynistic joke or talking about a woman who is not there in a disrespectful way…to something very overt, an effective way to defuse the situation is to make salient that morally this isn’t right…to say, ‘Hey, she doesn’t want this.'”