If you’re wondering why a movie that glamorizes a young woman’s sexual subjugation by a sadistic older man opened to record-setting crowds—on Valentines Day weekend, no less—you’re not alone.

At a time when concern about campus rapes, domestic violence, and sexual assaults against women is at an all-time high, the appeal of the book and the movie versions of “Fifty Shades of Grey”—a story that celebrates a man sexually abusing a woman—is hard to explain.

Or is it? Unless you believe the 100 million women who bought the book and the millions more who are seeing the movie have gone mad, or are just plain dumb, it makes sense to search for underlying reasons for the movie’s popularity.

It’s likely that “Fifty Shades” has tapped into deep-seated psychological needs of modern women that have been suppressed by our culture.

The most convincing theory proposed by social critics is that the popularity of “Fifty Shades” is a perverse but predictable reaction against our culture’s “genderlessness”—an ideology that says there are no psychological and emotional differences between men and women.

According to social critic Camille Paglia, “gender ideology … denies that sex differences are rooted in biology and sees them instead as malleable fictions that can be revised at will.”

In recent years, this point of view—that sexual differences don’t matter—has won victory after victory. From the legal decisions in favor of gay marriage, to the 58 gender options introduced by Facebook last year (including letting users select between three pronouns: “him,” “her” or “their”), cultural elites have led a successful campaign to erase the biblically-rooted idea of two complementary sexes: “male and female he created them (Genesis 1:27).”

To counter this trend, the Vatican last year hosted an international conference in Rome on the subject of “The Complementarity of Man and Woman.” The conference’s theme, presented in speeches and videos by leaders and groups representing almost every religion, built upon ideas contained in Scripture, that masculinity and femininity together reflect and complete humanity’s divine design. “In sexual difference,” one speaker explained, “… the male needs the female to be understood, and the same is true for the female … each of the two can only understand him or herself in light of the other.”

Or, as St. Pope John Paul II said in 1995 in his “Letter to Women,” “It is only through the duality of the ‘masculine’ and the ‘feminine’ that the ‘human’ finds full realization.”

The relationship portrayed in “Fifty Shades of Grey,” between Christian Grey and Ana Steele, bears a certain resemblance to traditional ideas about the mutual dependency of men and women. The powerful and charismatic man, Christian Grey, is really a wounded soul, who survived a tormented childhood. He can only find sexual satisfaction by dominating and hurting women. Ana Steele is a younger woman, shy and unsure of herself, who takes his wounds upon herself and becomes his willing victim. She ultimately realizes herself by “saving” him. The story ends in a “happy ever after” marriage.

There is a certain appeal to the story: “What woman can resist the subliminal need to nurture a tortured soul?” wrote Catholic therapist Allison Ricciardi. “Buried beneath all the smut, poor writing and abuse, on some level this book appeals to that nurturing part of every woman that makes her feminine and beautiful.”

Secular commentator Janet Albrechtsen adds, ”The deliciously complicated, frustratingly messy truth about women’s preferences,” she says, “be they about work, babies, men, sex or, for that matter, books—has never conformed to feminist orthodoxy.”

But despite this surface appeal, ultimately, Fifty Shades makes a mockery of the Christian idea of sexual complementarity. Christian and Ana’s relationship is built not on mutual, self-giving love, but on male dominance and female submission rooted in sexual sado-masochism.

“An intimate relationship that includes violence, consensual or not,” warns Dr. Miriam Grossman, “is completely unacceptable.” Women—and especially young women—need to be warned away from the toxic version of romance portrayed in “Fifty Shades.”

Unfortunately, there are many self-proclaimed “pro-sex” feminists who are selling “Fifty Shades” as a story of women’s sexual liberation—an antidote to the “anti-sex” feminist narrative that portrays most men as sexual predators. For example, Esther Perel, a sex and relationship expert, says

“…the woman who says I am sexual frees the man from his predatory fear. If she says ‘I like it too,” he is freed from the fear of hurting her, from her fragility, from the need to protect her, because she basically says I enter into the playground of the fearless together with you.”

Perel’s idea of sexuality will sound liberating to many young women, if only because in recent years radical feminists have demonized male sexuality by sensationalizing cases of rape and sexual assault. These feminists also claim that violence against women is rooted in traditional values about marriage and family.

But Fifty Shades falls into the trap of “liberating” women by telling them to imitate the sexual behavior of the worst sorts of men. The simple fact is that when women descend to that level, they get hurt, because they are physically and emotionally more vulnerable than men. When sexual differences are ignored, women aren’t liberated. On the contrary, men are liberated from their responsibility to protect women, an obligation expressed by St. Paul when he said “…husbands should love their wives as their own bodies. [Ephesians 5:28].“

As Pope Francis said recently, “This revolution in manners and morals has often flown the flag of freedom, but in fact it has brought spiritual and material devastation to countless human beings.”

The millions of women attracted to “Fifty Shades of Grey” aren’t looking for abuse. Many of them are expressing a distorted desire for a lost sense of romance, rooted in traditional ideas of male-female differences. But until a healthy understanding of sexual difference is restored, we’ll continue to see both women and men looking for love and romance in self-destructive ways.