Even happy couples cheat. But how and why a spouse sneaks around depends largely on whether the cheater is male or female, studies suggest. Men cheat simply because the opportunity presents itself, even when they perceive their lovers as inferior to their wives. Women, on the other hand, tend to cheat up—replacing their spouses, selectively, with superior lovers.
“Some research suggests that women are more likely to cheat when they don’t feel appreciated, loved or understood, more than men,” Tim Cole, a professor at DePaul University and author of Broken Trust: Overcoming An Intimate Betrayal, told Fatherly. Studies suggest that men make fewer such calculations. “Men might be a little more opportunistic on average.”
From an evolutionary standpoint, infidelity makes sense. “We romanticize the idea of marriage and finding that one person and tend to have a very negative view of infidelity, but the underlying reasons for cheating have never really changed,” Cole told Fatherly. Most animal species are non-monogamous because they’re playing the odds, he adds, and it is not an evolutionarily wise decision to put all of your eggs (or whatever genetic material you may have) in one basket.
“The best analogy would be investing all of your retirement funds in one stock,” he says.
The biology of infidelity may shed light on why men and women appear to cheat differently. Since most male animals are able to reproduce with an unlimited amount of partners (and only minutes of work), it’s in their best evolutionary interests to be more or less indiscriminate about whom they impregnate. Female animals, on the other hand, are more limited in their reproductive capacities, and the survival of their occasional offspring depends on mating with only the healthiest males. So it makes some sense that males would cheat whenever the opportunity presented itself, while females would only cheat as a way of investing in healthier, or otherwise more eligible mate. Indeed, men and women cheat along those same biological lines.
But biology is only piece of the infidelity puzzle when it comes to humans, who have deep social and romantic reasons not to betray their spouses. Cole says that, in many ways, cheating is less about gender and more about the couple’s feelings for one another. “The best way to look at infidelity isn’t male versus female, but it’s really to look at the relationship,” he says, noting that individuals with insecure, anxious, and dismissive attachment styles, with low levels of conscientiousness and high levels of opportunity are the most likely to cheat. “Focusing on your partner’s sex isn’t as important as these other factors.”
Interestingly, less is known about the difference between parents’ propensity to cheat, compared to people without kids. Cole, who could not recall any research that has addressed this specifically, speculates that the stressors of parenthood could compel cheating, but that “there’s a lot more pressure to stay together as well,” he says. This, at least, should apply equally to both men and women. “It’s not like men and women are separate species,” he says. “they’re more alike than they’re different.”