There is no shortage of research about why people cheat. Perhaps the most common belief, one we’ve embraced and built an entire culture and gender script around, is a neat binary asserting that men want sex and women want connection and intimacy. You can’t Google “affair” without eventually running into this supposedly “universal truth” about lust and commitment. But tell it to Alicia Walker’s study participants, the ones who went on Ashley Madison to find and audition men who could provide them with what they didn’t have in their marriages: sex. And the ones in avowedly heterosexual marriages who seek out other women online for one-time sexual encounters. Tell it to couples therapists like Tammy Nelson, author of The New Monogamy, who says that in her experience, “men and women basically want the same things when they’re having an affair. They want sex and connection. I wish I had known that earlier in my life and career—that when it comes to motivation, men and women are really very similar.” Too often study participants are asked questions that lead them to answer a certain way, or they feel pressured by an overarching cultural script to do so. Women told they seek intimacy and emotional connection are likely to internalize that that’s how women are, so that’s how they should be, and then researchers hear what they expect, and so there is little incentive for them to ask the kind of questions Lisa Diamond and Sarah Hrdy did about male and female sexual motivations, identities, and desires. Such self-reporting is a slippery slope when ideology looms so large.
But like the women in Walker’s studies, some women apparently buck the dogma. Of the 2,000 surveyed female users of the Victoria Milan website for married people seeking affairs, most responded “to add excitement to my life” (35 percent) when asked why they cheated (and a whopping 22.5 percent, more than one in five, reported doing so because they were unsatisfied in their marital beds). In a 2011 Kinsey study of infidelity and “sexual personality,” researchers found that the 506 men and 412 women surveyed online cheated at a statistically comparable rate. They also found that fear of sexual performance failure upped the chances that both men and women would have extra-pair sex—maybe because a new, one-time partner was a chance to pretend there wasn’t an issue, or presented an opportunity to be so excited that there wouldn’t be an issue. Finally, those women who reported being in sexually incompatible marriages or relationships were 2.9 times as likely to cheat as women who didn’t. In her Good in Bed survey of 1,923 women and 1,418 men, sex researcher Kristen Mark discovered that men and women were equally likely to consider infidelity due to “boredom” in a relationship, and that in the first three years of a relationship, women were roughly twice as likely as men to become bored.
Some women have extra-pair involvements because they can. Having access to resources, and particularly being the breadwinner or main provider of one’s household, frees up women in the industrialized West to be sexually autonomous just as it did Wyandot women, who lived in a society where women had high status because they provisioned the group. I heard at least a dozen stories from women telling me about friends or friends of friends who were independently wealthy, had their own homes and trust funds or accumulated or earned wealth, and so were in a position to call the shots about their sex lives. In this category, Tilda Swinton comes to mind. Rich, beautiful, and powerful, for a time she reportedly lived in a castle in Scotland with her life partner, with whom she had twins, and also with her nearly twenty-years-younger boyfriend (in an interview with Katie Couric, among others, Swinton denied being in a “dual relationship” with the men, though did not deny having an arrangement that might appear unusual to some). A woman told me about an acquaintance, an heiress who lived in a fabulous house with her husband—and also had a relationship with the father of her young child in Europe. She shuttled back and forth between men and continents. In the absence of intensive kin support, money can act as a buffer against restrictive ideology and the threat of consequences for female sexual autonomy, including male reprisals like withdrawal of support and even violence. It is harder to imagine raising your hand against a woman who owns the house you live in and puts food in the pantry than it is against one you yourself support.
Other women are “untrue” because they have to be, are expected to be, or because it is practical. In many partible paternity cultures of South America, a monogamous woman may be considered both stingy and a bad mother. Closer to home, the anthropologist Arline Geronimus has demonstrated in her work and her article “What Teen Mothers Know” that in areas of the US where sex ratios are skewed against women—that is, where there are notably fewer men than women—delaying childbearing and monogamy are reproductive and social strategies women can ill afford. In neighborhoods where there are high rates of incarceration, for example, women and children may benefit from serial relationships and depending on extended family and other kin support to raise their children. Contrary to what social conservatives assert, this has less to do with morality and more to do with material circumstances and the kind of maternal strategizing and trade-offs in a sometimes hostile environment—in this instance, one ravaged by institutionalized racism—that helped Homo sapiens thrive.
There are other drivers that may be difficult to “feel.” Some evolutionary biologists believe that we step out in search of a partner with whom we are compatible on a genetic level. Who can forget the famous T-shirt test? In case you have, it presented forty-nine women with T-shirts that had been worn for two days by men who didn’t use any cologne or deodorant or soap. When asked to sniff the tees and rate the sexiness of the smells, women chose the shirts of guys with something called major histocompatibility complex most different from their own. In general, the more different the MHC of both parents, the healthier the offspring. The T-shirt test suggests that smell may well be at work in mate choice, and that we are attracted to mates through olfaction based on how good a genetic match they are, which is to say, how different certain of their genes are. Specifically, the genes that make molecules that allow the immune system to recognize invaders. Leslie Vosshall, a neurobiologist who studies olfaction, says, “It seems unlikely that humans would not use this system, given how many animals clearly demonstrate responses to MHC odortype.” So there’s that. (The study findings were reversed in women who took the pill. Block our hormones and our noses don’t work right and we are more likely to pick the wrong fellow. You may be used to hearing that hormones “drive” men, but this study suggests that women are hormonally driven too.) Another study of Hutterites found that those with closely matched MHC had longer interbirth intervals (that is, it was harder for the women to get pregnant) and more miscarriages. This body of research would suggest that the hard-to-describe attraction you feel for someone, that irresistible pull they exercise over you, might be that they are a better genetic match. Woe to the woman who marries a man who isn’t—she might forever be sniffing around for a guy with the ineffable je ne sais quoi (well, MHC) she craves.
So we know something about who the women who have affairs are. They’re you and me. They’re bored in their marriages, or sexless and orgasmless in their marriages, or happy in their marriages but eager for sex with someone other than their spouses, or they have money and power so they can do what they want, or they live in a culture that dictates that monogamy is stingy, or where monogamy isn’t an option. Or they have a particular sexual “personality.” Not unlike men, they often do it simply because they feel like it. For fun or for payback or because they are out of town or they had one drink too many and succumbed to their feelings for that woman at work. Whatever the reason, for that window in time, whether the encounter is under an hour or an affair that extends for years, when they are doing it they are not mothers or wives or employees. They are not honest and they are not self-sacrificing. They are not good; they are not admirable. But make no mistake, they are being themselves. Part of female sexuality, part of its legacy and its present and its future is that it is assertive, pleasure centered, and selfish. No amount of pathologizing can change the deep lessons we glean from the Wyandot and the Himba, from Amy Parish’s bonobos and Sarah Hrdy’s langurs, from the laboratories of Meredith Chivers and Marta Meana and Lisa Diamond’s twenty years of interviews: that when ecological circumstances are right, women are just as likely to step out as men are. Our dearest held binary cannot hold. The world is being rewritten. But certain rules and formulas adhere, and the lesson from cultures across the world and the women you know is clear: there can be no autonomy without the autonomy to choose, without coercion or constraint, or in spite of it, who our lovers will be.