Monogamy is a nice idea in theory, but in practice, humans are less adept at it than they might admit. I mean, let’s be real: As long as relationships exist, there will be infidelity, and if recent studies are to be believed, there will be more of it all the time. Because we’re animals, people. And sometimes animals think with their loins, not their vows.
We’re not championing infidelity, but we are saying it’s a reality, and aspects of it are fascinating. From who gets away with it (almost everyone, but women especially) to where the most American cheaters live (I’m looking at you, Austin, Texas), there are some really interesting facts about cheating and those who indulge in it. Here’s a list of nine of them.
1. Women are most likely to cheat when they’re ovulating.
As biology class taught us, the peak fertility point in a woman’s menstrual cycle occurs during ovulation. That’s also the period when women are most likely to cheat, as nature throws pretty much everything it’s got at species propagation to see what sticks. Studies show a whole host of changes occur in women’s bodies during this window of max fertility. Their voices get higher and are “judged more attractive.” They dress in more ornamental ways — with greater likelihood of wearing clothes that are red or pink— and they opt for outfits that reveal more flesh. They wear more makeup. Even the way women walk changes, becoming “slower and their gait [is] subjectively rated as sexier.” Men find women smell more attractive during ovulation, even identifying the odor left behind on ovulating women’s T-shirts as more sexually attractive than the smell of non-ovulating women. For their part, ovulating heterosexual women become more sexually attracted to “manly men” — described by researchers as “muscular, symmetrical, socially dominant guys with pronounced brows and strong jawlines”— at least in cases when their current partners lack those traits.
2. Women are cheating more than ever.
While estimates of the exact percentage of women who have extramarital affairs varies from study to study, there does seem to be evidence that the number is on the rise. A 2010 study from the National Opinion Research Center found that over the last 20 years, the number of married women who admitted to affairs rose a staggering 40 percent. Which we can all agree is a lot. Nearly 22 percent of men copped to sex outside of marriage, a number that’s remained fairly consistent since 1991. For women, that percentage rose to 14.7 percent. A number of theories are floated for this change, including increased financial independence for women, the fact that women spend more time in co-ed working environments (most affairs begin in the workplace) and changing attitudes around women’s sexuality.
3. Male biology, including penises, has evolved to compensate for cheating.
We all watched Planet Earth. (Ed. Note: If you haven’t, stop what you’re doing and stream it on Netflix right now. I’ll wait here.) So we all know that competition among males of multiple species to ensure their sperm wins out against all competitors is fairly common in nature. More recent studies of humans suggest the same is true in our case. “Sperm competition” is the catch-all phrase for the myriad ways that male spermatozoa rival each other for the victory of fertilization — or at least to prevent other males’ sperm from doing so. In one study, researchers found that the human penis acts as a “semen displacement device,” a term that deserves a blue ribbon for making guys’ junk sound like the most unsexy thing ever. Using artificial penile stand-ins (aka dildos shaped like real penises), scientists found that the penis’ coronal ridge effectively displaced more than 90 percent of semen that stood in its way during sex. Without the coronal ridge, that number plummeted to 35 percent.
Another study found that men who were away from their partners for periods of time when infidelity could have taken place returned with greater interest in having sex with said partners and were more persistent about it. When men believed infidelity had taken place in their absence, the sex that followed “involved deeper and more vigorous penile thrusting,” presumably as an unconscious effort to “move to the front of the line,” if you will. There’s even one theory that “kamikaze” or “fighter sperm,” which exist for the sole purpose of taking out other men’s sperm, make up 40 percent of ejaculate in men who think a partner has been unfaithful. But that theory is the subject of pretty hotly contested scientific debate.
4. Women cheaters are better at not getting caught than men.
Most cheaters, across the board, don’t get caught. A recent survey found that 89 percent of spouses engaged in extramarital affairs are able to keep their infidelity on the down-low. But women are better at keeping their affairs a secret than men. One study (conducted by a website that helps people cheat, no less) found that while 83 percent of men reported getting away with extramarital affairs, a whopping 95 percent of women said the same. Interestingly, part of the reason might have to do with testosterone. Levels of the hormone rise and fall in men, increasing with success and falling with failure. In studies, men with higher levels of testosterone exhibited correlating behaviors that made them more attractive to potential mates, such as greater confidence and “aggressiveness toward competing men.”
But greater levels of testosterone also have a direct impact on risk-taking behaviors (dudes who work in finance, for example, have particularly high levels of the stuff). When men in studies were injected with testosterone, they became more selfish and focused on immediate gratification, without a lot of concern for long-term “cost-benefit calculation.” Basically, all that acting on impulse made them both sloppy and cocky, which is a good way to ensure they'll be caught. As the CEO of one dating site told Forbes magazine, “You often don’t catch the women. Because women naturally think more contextually. They consider long-term vision and potential consequences much more thoroughly before acting.”
5. Wealthier, better educated people are more likely to cheat.
A 2002 University of Washington study found that infidelity and salary go hand in hand. People who make $75,000 and up are 1.5 times more likely to cheat than those whose annual salaries are $30,000 or less. Those with graduate degrees are also more likely to seek sex outside of marriage, being 1.75 times more likely to have an extramarital affair than people who haven't graduated high school. Living in a city also ups one's chances for cheating by a factor of 1.5 times. As does age at marriage: those who tie the knot at 16 or younger are 4.5 times “more likely to report infidelity than were respondents who were married at 23 years of age,” according to research findings.
6. People nearing “milestone” ages are more likely to pursue affairs.
As we near ages that end in zeroes, the chances for infidelity increase. A 2009 survey found that people staring down the next decade of life, age wise — meaning those who are 29, 39, 49 or 59 — are more likely to engage in extramarital affairs than people at other ages. As one researcher noted, “The prospect of getting older ... can make us re-evaluate our lives and relationships, and ask ourselves whether we are truly happy. If we are unhappy at this point, we are likely to seek a solution — and it seems many married men and women see us as that solution. Secondly, the approach of a milestone alerts us to the fact that we are getting older. Having an affair can make us feel young and sexy again, perhaps at a time when we feel the opposite."
7. These are the 10 American cities with the most cheaters.
Although it’s a fairly unscientific study based on one source for its numbers, a 2015 survey does give some insight into which cities are greater hotbeds of cheating than others. 24/7 Wall Street crunched the numbers from AshleyMadison.com, a casual encounters website for married people looking to cheat (let’s just call a spade a spade) which has nearly 17 million users. The survey found the cities with the most adulterers were as follows: 10) Charlotte, North Carolina; 9) San Diego, California; 8) Houston; 7) New Orleans; 6) Las Vegas, Nevada; 5) Los Angeles; 4) New York City; 3) Boston; 2) Pittsburgh, Pennsylvania; and at No. 1) Austin, Texas.
8. Really active social media use may be connected to cheating.
To be clear, no one’s saying that the rise of social media has caused infidelity to rise. However, there does seem to be a correlation between relationship issues, including extramarital affairs, and social media. A University of Missouri-Columbia study found that “active Twitter use leads to greater amounts of Twitter-related conflict among romantic partners, which in turn leads to infidelity, breakup, and divorce.” (For the record, in a previous study, the researcher discovered similar patterns of relationship tumult and dissolution related to heavy Facebook use.) There’s also that 2011 study from OkTrends, the research arm of OkCupid, which consistently produces really interesting data around dating and relationships, which found that people who use Twitter every day tend to have shorter relationships than those who don’t, regardless of age. And not that it’s totally germane, but daily tweeters were also more likely to masturbate on a daily basis. So do with that what you will.
9. Broken penises are possibly, but only possibly, connected to cheating.
Again, correlation and causation are two different things, and we’re not suggesting they should ever be confused. But the results of one tiny study yielded interesting findings about penis fractures and infidelity. Andrew Kramer, an assistant professor of surgery at the University of Maryland Medical Center, investigated the cases of 16 men who had penile fractures that were severe enough to require surgery. Of that tiny sample — all cases between 2007 and 2011— half of the men had been engaged in extramarital sex when the injuries happened. Coincidence? Definitely maybe. There’s no way to extrapolate any significant truths about penis fractures and infidelity with so few subjects studied. But it’s kind of a neat factoid nonetheless.