The pull of Guyland reminds us that women cannot accomplish this transformation alone. In the book's final chapter I argue that just as men need to stand up, do the right thing and break the silence that perpetuates Guyland, so, too, do women need to support each other in resisting its pull.

So guys who are otherwise sensitive and thoughtful say and do ridiculously dumb things to impress other guys. It's an enormous performance, but guys know that if they fail, they'll be ridiculed as sissies mercilessly.

Young men are eager to "hook up" with women. And many say they have very good female friends. But some of the emotions circulating among guys make it difficult to form and sustain healthy relationships.

The pull of Guyland reminds us that women cannot accomplish this transformation alone. In the book's final chapter I argue that just as men need to stand up, do the right thing and break the silence that perpetuates Guyland, so, too, do women need to support each other in resisting its pull.

We have the data to prove to men that gender equality is not a zero-sum game, but a win-win.

Guys constantly talk about pornography in two ways: as revenge and as reassurance. When you live in a world in which beautiful, sexy women are all around you, in the same classes, on the same athletic field, competing for the same jobs, then the pornographic world - the world in which women thrill to male sexual desire - reassures men that although they may feel "one down," they're still entitled to women's bodies.

My colleagues and I have done a survey of 13,000 students on more than 17 campuses, and we found that while sex in college has always been a bit more casual, "hooking up" has pretty much replaced other traditional forms of dating.