I teach at the University of Pennsylvania, where new students have to take an online training about sexual assault. They are also required to participate in student-led "Consent Circles," where they learn the so-called FRIES definition of consent: it should be freely given, reversible, informed, enthusiastic, and specific. "Of course it should be," a student recently told me. "But if you didn't get that message before you got here, a single training isn't going to make a difference." Everyone knows the right answer in these sessions — to get consent — so they mouth the words and move on.

I have been thinking about this student's comments since a former Cornell student sued the university and seven men who allegedly raped her at a fraternity house in 2024. In response, critics have called on colleges to enhance their educational efforts around sexual assault. We should all want that. We should also be realistic about what we can accomplish. Under the Campus Sexual Violence Elimination Act of 2013, every university receiving federal dollars already has to implement sexual assault prevention programs. But there is scant evidence that they reduce sexual violence.

Those of us who teach at universities like to imagine that students arrive here as blank slates, because we want to matter. The more we can imprint on them, the more important we become. But on matters of sex, especially, students receive their most significant education many years before they set foot on campus. And they get it mostly on their phones.

I am talking about pornography, of course. When I say "sex education," you probably think of your gym teacher lecturing awkwardly about the sperm and the egg. But when it comes to the sex act itself — how to do it, and with whom, and why — kids learn much more from the internet. According to a 2022 survey by Common Sense Media, 73 percent of 13- to 17-year-olds had watched pornography. The average age of first exposure was 12.

And 15 percent of respondents said they had seen it by age 10 or younger. Of teenagers who intentionally watched porn, 71 percent said they had watched it during the previous week. Nearly half of them agreed that pornography provided them with "helpful information" about sex. We need to think much more about that information and whom it helps. Or hurts. Analyzing 255 popular videos posted between 2000 and 2024, a recent study found that nearly half of them depicted "visible physical aggression": spanking, hitting and choking. The rate of visible aggression had tripled over this span.

I don't know what caused the seven assailants at Cornell to allegedly assault the woman who is suing them. I don't know why they reportedly snorted ketamine off her body or why one of the men had her ingest the drug off his penis. I don't know why another of the assailants texted "free p----" to the fraternity group chat, encouraging more brothers to join in. I don't know why someone asked a few hours later whether the "shop" was "still open."

And I don't know why one of the assailants allegedly hit Jane Doe so hard while he was having intercourse with her that he left bruises on her buttocks. But I would be shocked if these men weren't inspired — at least in part — by pornography. If you grow up bombarded by imagery that degrades women, you'll be more likely to believe that they exist simply for your pleasure. And you will behave accordingly. I'm not suggesting that everyone who watches pornography becomes a rapist. Nor am I pleading for censorship of pornography, which would be impossible anyhow.

In the digital era, that ship has sailed. Instead, we need the adults in the room to step up and discuss these issues with young people. That starts with parents, who are always our first educators. Ask your kid what he's watching and what he is learning from it. Our schools need to do the same thing.

It's enough to teach students about consent, which is now a required topic of instruction in 15 states and the District of Columbia. That's necessary — and long overdue — but it's not sufficient. Forty years ago, the HIV/AIDS crisis changed our national and global dialogue about sex education. It forced us to address formerly tabooed topics — especially contraception — so young people learned how to keep themselves safe. I hope the Cornell story can inspire another revolution in our classrooms, moving us beyond safety — and consent — and into sex itself: what students see online about it, what they want from it, and why.

And we can't wait until they're in college to do that. Every middle and high school should sponsor lessons and assemblies about the incident at Cornell. Most of the students have already seen video about it, just like they have watched porn. The only question is whether we can summon the courage to talk to them about it, and to give them the sex education they need. Jonathan Zimmerman teaches history and education at the University of Pennsylvania and serves on the advisory board of the Lepage Center for History in the Public Interest. He is the author of "Too Hot To Handle: A Global History of Sex Education" (Princeton University Press).