Harvard president Drew Faust has ordered that single-sex social clubs begin allowing both men and women to join. This includes a handful of fraternities and sororities as well as a set of similar organizations called Final Clubs, historically elite institutions to which some of the most powerful men in the U.S. have belonged.

The decision came after an investigation found strong evidence that the male-only organizations nurtured “cultures that reflect male control,” “the marginalization of women” and “sexual entitlement.”

The decision, in other words, is about addressing the problems caused by male-only organizations.

Should the president of Harvard penalize social clubs that do not allow women?

Defenders of such organizations say that excluding women isn’t about superiority, but difference. They say that it’s meaningful for men to be in male-only spaces in order to develop specifically masculine self-concepts. Such self-concepts, they say, are necessary because men’s self-esteem depends on differentiating themselves from women. It’s not because we think men are better, they say.

Oh, really?

It’s funny because such men are perfectly happy to have women in their male-only spaces if those women take on subordinate roles. Clubs ensure there are women to hit on at parties. Fraternities are happy to have “little sisters” or allow women as cooks and maids. They just don’t want women to be members.

They don’t want any women except as sex objects, cheerleaders and servants.

Their selective inclusion of women reveals a more nefarious process than differentiation. By refusing to engage with women as equals, these organizations are engaging in dehumanization. Their actions reinforce the idea that men are the important, valuable, significant humans and women are something else.

Consider that for Harvard women, the biggest risk factor for sexual assault is entering a Final Club. By their senior year, 47 percent of women who have done so report having been assaulted. Most sexual assaults occur in the dormitories, but Final Clubs are the second most common location.

Separate, they say. But equal? No. These statistics reflect how male-only organizations encourage men not just to identify as men, but to dis-identify with women: to see women as an out-group, a pawn perhaps, in a game between men.

The men in these clubs become some of the most powerful people in the world. They run our companies, ascend our political hierarchies and control our media. If they’re allowed to segregate themselves from women during college, why would we expect them to make a place for women as equals in the worlds they later control?

Ending the sex-exclusivity of these organizations is not just resisting the regulation of women to second-class status at Harvard, it’s ending the university’s complicity with the persistence of sexism writ large.

In the aftermath of the election of an unapologetic misogynist to the U.S. presidency and revelations about the discomforting, grotesque, and violent treatment women receive from some men at work, we are beginning a conversation about the costs of some men’s dehumanization of women.

Women have responded with #metoo, the Women’s Marches, and an incredible post-election surge of 30,000 women running for office. Women are announcing that they’ve had enough. I’m encouraged that the president of Harvard is among them.

Lisa Wade is an associate professor of sociology at Occidental College. Her latest book is, “American Hookup: The New culture of Sex on Campus.”