Hair color? Deep Voices? Facebook? See what else is leading to adultery, according to science.
Size does matter ... just not the size of what you think.
A study claims that women are more likely to cheat on their man if he has big balls. (Yep, you read that right.) Researchers from the University of Oslo studied primates — bonobos, specifically — and found that a female is more likely to have other sexual relationships if their mate has large testicles.
And it doesn't stop with monkeys.
"In one type of grasshopper, the testicles occupy half their body mass. The testicles are even larger in sea urchins. They spawn directly into the ocean. To increase the chance of fertilizing an egg, the sea urchin is a huge testicle with a little shell around it," the study says.
The testicles of humans are one and a half times larger than those of gorillas. The researchers claim this shows that we're an unfaithful race by nature.
Personally, I'd like to know why they decided to study monkeys, bugs and sea urchins to determine human behavior, but I digress. The point is that you'd probably have to have big balls to interject yourself into someone else's relationship. (Bro code, guys?)
Still curious about other bizarre facts found from cheating studies? Here are 10 research-proven facts that had us do a double-take:
1. Facebook is an affair waiting to happen.
They say that Facebook can figure out how long your relationship will last, but maybe the reason is because they are the culprit? This study published in the Journal of Cyberpsychology, Behavior, and Social Networking suggests that the social networking site leads users to re-connect with old flings, which in turn is leading to more affairs, breakups or divorces.
2. The French are big-time cheaters.
They say that the French make the best lovers in the world, but that doesn't make it true love. But a poll found that a majority of men and a third of women admitted to cheat on their partners, indicating that infidelity is on the rise in France among both sexes. Infidelity has been on the rise in that country since the 1970s, when only around 19 percent admitted to cheating (everything from kissing to swapping naughty texts).
3. People believe slapping the unfaithful is OK.
An eye for an eye, or rather, a slap for an affair. As part of the Crime Survey For England and Wales, ten percent of the total 38,500 people surveyed agreed that "hitting or slapping" your unfaithful partner is appropriate for a betrayal of the heart.
4. Cheaters love eating at chain restaurants.
Suspect that your partner is cheating? The first place you might want to scope out is a chain like Taco Bell. The infamous extra-marital affair dating website Ashley Madison asked over 40,000 cheaters where they loved to wine and dine in secret, and thus, revealed the top 10 dining destinations to have an affair. Among them? Red Lobster, Outback Steakhouse, Chili's and P.F. Chang's.
5. Cheaters love to shop.
After delving into the wine-and-dine habits of the unfaithful, Ashley Madison also scoped out the most popular shopping outlets. After polling 50,000+ women, more than a third admitted to spending double on keeping up their looks for their secret lover. In addition, 27 percent said they even have a secret credit card to keep their financial infidelity under wraps.
So what are some of the other popular stores for cheaters? J. Crew, Macy's, Ann Taylor and H&M all ranked high on the list. (And here you thought she was just getting a new suit jacket for work.)
6. Faking an orgasm is a red flag.
If your partner is faking it in bed, watch out. It could be a bad sign that he or she is getting action in a bedroom somewhere else. One study claims that both men and women who faked orgasms were far more likely to be unfaithful.
7. Sperm can tell if your partner is cheating.
Clinical sexologist Dr. Lindsey Doe told The Daily Mail that a man's sperm reveals whether he thinks his partner is cheating or not. According to her, 40 percent of ejaculate is made up of what she calls "kamikaze" or "fighter sperm" designed to block another man's sperm from inseminating the egg.
When a man suspects his partner of being unfaithful, he produces more of his fighter sperm to ward off other suitors. Granted, you need a microscope to see the differences for yourself, but just in case you have a lab handy...
8. Jews are more faithful than Christians.
In an annual survey released by JDate.com and Christian Mingle.com — which surveys the two online dating communities on their dating etiquette, social influences, and attitudes towards infidelity — an interesting result revealed itself: 84 percent of Jewish singles reported that they've never cheated in a relationship, as opposed to only 66 percent of Christian singles.
9. Men with deep voices are often perceived as cheaters.
Barry White might have had one of the sexiest voices of all time, but if this study is any indication, a deep voice is a perceived clue to infidelity.
According to research published in the journal Evolutionary Psychology, women fear that men with deeper voices are more likely to cheat on them, whereas men think women with higher-pitched voices will cheat on them. That's because the more testosterone a man has, the lower his voice; the more estrogen a woman has, the higher her voice.
10. Blonde women cheat the most.
Blondes have more fun (like, a lot more fun). CheaterVille.com conducted a survey to find out whether hair color could be an identifying factor in someone's likelihood to cheat, and blondes were caught red-handed.
They found that 42 percent of cheating women have blonde hair. After blondes, redheads were second-most likely to cheat at 23 percent, followed by brown-haired women (20 percent) and black-haired women (11 percent). But we have to wonder if that's au natural or not.