Men cheat because their wives are fat. That's one odious bit of conventional wisdom that gained airtime recently courtesy of Noel Biderman, CEO of Ashley Madison, during his appearance on an episode of "Inside Amy Schumer." It isn't news that the wildly successful extramarital "dating site" views overweight women as a cause for cheating: The company once ran a controversial ad explicitly suggesting as much. Is it true, though? Do men cheat simply because of a couple extra pounds?
I mean, obviously not. What a douche-nozzle. David Ley, a a clinical psychologist and author of “Insatiable Wives: Women Who Stray and the Men Who Love Them," agrees.
“That's a ridiculously simplistic assertion,” says Ley. "People cheat for many reasons and the attractiveness of their partner has little to do with it. Look at Christie Brinkley's husband, and any number of men who are married to beautiful women, who engage in infidelity.” Biderman may be the CEO of an incredibly popular infidelity website, but it doesn't mean that he understands why people cheat. So, then, why do people cheat?
Ley says the motivations tend to be different between the sexes. "For men, cheating is more often an adventure, an affirmation of their virility and their manhood,” he says. “Men most often cheat with one-night stand type flings.” Ladies, on the other hand, tend to really commit to their infidelities. “Women cheat more often in longer-term extramarital relationships, where they develop more intimacy,” Ley explains. “For women it's also about feeling attractive, but also about developing a connection.” Some theorize that “women's infidelity is sometimes about looking for a backup plan man, in case their mate leaves them,” he adds.
That all tends to confirm certain gendered expectations about infidelity, but Ley did add one surprising, counterintuitive observation: "For neither men nor women is infidelity an inherent sign or reaction to relationship problems." That's because cheating happens in perfectly happy relationships, too. That said, research has found that marital dissatisfaction is correlated with extramarital affairs, and so too is sexual dissatisfaction. In fact, that's one area where you see sex difference in cheating disappear. A 1997 study out of the University of Texas at Austin concluded, "For both men and women, dissatisfaction with marital sex is a predictor of susceptibility to brief affairs."
Certain personality traits also can play a role in infidelity -- namely, narcissism and what researchers refer to as "low-conscientiousness" and "high psychoticism." In other words, self-absorption, indifference and straight-up craziness make one more susceptible to infidelity. Several other traits have been linked by research to cheating, which the University of Texas study summarized like so: "Individuals who engage in infidelity are more open to new experiences and extroverted than their partners ... and more susceptible to boredom," the study said. "Sexual infidelity is also associated with low agreeableness … with low conscientiousness, and with higher neuroticism, or lacking positive psychological adjustment." It was even suggested by a study in 2010 that half of people have a gene that makes them vulnerable to cheating.
Naturally, there are also some evolutionary theories about why people cheat, granted these have less scientific evidence. As anthropologist Helen Fisher has written, "D]uring prehistory, philandering males disproportionately reproduced, selecting for the biological underpinnings of the roving eye in contemporary men," she wrote. "Unfaithful females reaped economic resources from their extra-dyadic partnerships, as well as additional males to help with parenting duties if their primary partner died or deserted them." It's always so comforting to think of ourselves as stuck in the behaviors of our cave-dwelling ancestors, isn't it?
So, look, take your pick of explanations. No matter which of these you choose, infidelity, which impacts an estimated 40 to 76 percent of marriages, is not explained away by a couple extra pounds.