Booze-filled, chaperone-free parties. Teasing that crossed the line under the influence of alcohol. Relatively shy young men who became “aggressive and even belligerent” when drinking. Whatever the behavior of Supreme Court nominee Brett Kavanaugh, it’s become clear that the circles he traveled in as a young man — both at prep school and later Yale University — were characterized by young men drinking, a lot. And by young women whose social interactions were fraught with danger.

And this is no surprise to experts who study campus sexual assault. Years of research both in and out of the lab suggests that there is a connection between young men drinking alcohol and making choices that destroy young women’s lives. But it’s not accurate to say alcohol causes sexual assault. Preventing rape will take more than simply convincing young men not to drink (let alone telling their victims to abstain). That’s because booze is only part of the problem. Every drink is downed amid cultural expectations and societally mediated attitudes about women and power. Those things — and how young men absorb them — have a stronger causal influence than the alcohol alone. When a man feels entitled to assault someone, he may get drunk before he does it, but the decision to act was ultimately his alone.

Half of all sexual assaults involve alcohol consumption — usually by both the victim and perpetrator, said Kelly Cue Davis, a professor at Arizona State University. And a 2002 review of literature found that, across a number of studies, perpetrators were more likely to report using alcohol at the time of an assault than victims — 60 to 65 percent of perpetrators compared with 30 to 55 percent of victims. Although men can be both perpetrators of sexual violence and victims, almost all the research is focused on the heterosexual paradigm of male perpetrators and female victims, Davis said.

The best evidence for a causal connection between alcohol and the decision to commit sexual violence comes from experimental laboratory studies, said Dominic Parrott, professor of psychology at Georgia State University. In this kind of research, scientists take otherwise similar men and randomly split them into one group that is given alcohol and one that is not. Then they present both groups with proxies for a potential scenario in the real world — an audio scenario depicting an ethically questionable sexual encounter, for instance.

The men are then asked to tell the researchers when they would back off and leave the woman in the scenario alone. “Men who are drinking tend to let those interactions go a lot further,” Parrott said, “past the point where most people would say it’s consensual.” In one study, those who drank alcohol listened an average of 30 seconds longer to the tape than those who didn’t drink anything (even if they thought they did). Those 30 seconds included an escalation by the actors on the tape from verbal pressure to threats.

There are also a few studies that show a connection between committing acts of sexual violence or aggression and an increased likelihood of having drunk alcohol in the previous few hours. This research asks men to keep daily records of their drinking and sexual activities. It’s expensive and difficult to do, said Maria Testa, professor of social psychology at the University at Buffalo, but it’s one of the few ways we can show a causal link outside the lab.

Testing what causes real-world sexual assaults is particularly complicated by the fact that the men who commit them have things in common with each other that go far beyond booze. If you compare men who have perpetrated sexual assault to those who have not, the perpetrator group always drinks more, Testa said. For example, one study found that 53 percent of men who reported committing sexual violence met a diagnosis for alcoholism, compared with 25 percent of sexually active men who did not report committing sexual violence. But the impact of these other variables — anti-social behavior, for instance, and negative views about women — are much stronger predictors of sexual violence than alcohol use. “And then alcohol is just sort of on top of it,” she said.

Take a 2015 study that followed more than 700 men through four years of college. This research categorized the men into four groups based on the frequency of sexual assaults they reported committing and how that frequency did or didn’t change over time — low frequency, high frequency, trending toward lower, and trending toward higher. Alcohol use was always higher among the men who committed more assaults than among those who committed fewer, but trends in assault weren’t tied to trends in alcohol use. For instance, among men who reported committing fewer assaults over time and men who reported committing more assaults over time, each group drank less as seniors than they did as freshmen. But the men who committed fewer assaults over time also reported falling rates of impulsivity, hostility toward women, and beliefs that supported rape. The men whose rates of assault were going up, in contrast, reported a growing sense of peer support for forced sex, peer pressure, pornography use, and hostility toward women.

That makes sense if you think about it, Parrott said. After all, we know that not all men who drink, even excessively, commit sexual violence. Even men who do commit sexual violence don’t do it every time they drink — and will also do it sober. Effectively, alcohol isn’t an excuse. “We don’t want to say, ‘Well, he was drinking so that’s why he assaulted her. It’s not his fault,’” he said.

Instead, current research suggests that prevention should focus on those perceptions and behaviors that did strongly predict assault. Although they’re often referred to in the literature as “personality variables,” they aren’t immutable characteristics any more than personality itself is immutable. “There’s a small number of sociopaths, but there’s a lot of it that’s cultural,” Testa said. In other words: Are these men supported by peers who also voice negative attitudes about women? Is it considered socially acceptable to look for the drunkest girl at a party and try to take her home? Are there social consequences for young men who ignore consent?

The bad news about this conclusion is that these cultural attitudes are at least as widespread and as hard to change as teenage binge drinking. But change isn’t impossible. That strong social-cultural element is why the big focus in sexual violence prevention right now is bystander intervention — finding ways to encourage people who are neither victim nor victimizer to change cultural norms and stop situations that are turning dangerous. There’s a lot of evidence that this can be effective, Parrott said. In one study, researchers randomly assigned college men to participate in a program that combined bystander intervention training with other kinds of education about consent and sexual violence. Six months later, after administering follow-up surveys, researchers found the odds of committing sexual assault were 73 percent lower for men who had completed the training.

But here, also, there’s an issue with alcohol. Sexual violence tends to happen in settings where everyone is drinking — remember Kavanaugh’s prep-school’s party circuit. And there’s not a lot of research on how to prepare bystanders to step in and stop sexual violence when they, themselves, are also drunk, Parrott told me. In fact, self-report surveys suggest that alcohol can incapacitate the intercession. “People who drink heavily are less likely to intervene,” he said. Alcohol, it seems, might not be causing sexual assault — but it does contribute to our inability to stop it.