25 Scientific Facts About Cheating & Why People Cheat

Posted by , Updated on March 22, 2024

In 2015, cheaters were thrust into the limelight due to a significant data breach on the infidelity website, Ashley Madison, exposing the identities and specifics of thousands of unfaithful individuals. A large portion of these were stay-at-home dads or men with much higher incomes than their female partners—categories that research has revealed to have higher tendencies of infidelity.

Cheating is one of the most common plot lines for movies and novels across the world. From the woman who is unsatisfied in her emotionally distant husband to the man who is unhappy that he’s not getting enough action for his taste, the stories and archetypes are endless. In this list, we dig into the science of cheating and reveal what causes people to cheat, when people are more likely to cheat, and who is more likely to cheat. (The results will surprise you.)

Some of the research reveals that we’re easily driven by our biological impulses, just like our mammalian brethren. Other parts of the research reveal our complicated forms of cheating, made easier in the modern age with the rise of social media and technology. Check out these facts about cheaters, including the scientific basis for cheating, in this list of 25 Scientific Facts About Cheating & Why People Cheat.



Differences in the "happy hormone" affect our likelihood to cheat

food-man-person-eatingSource: ASAP Science, Image: Pexels

The neurotransmitter dopamine floods into our system after we do pleasurable activities such as eating food or having sex. Two different types of dopamine exist and our bodies genetically produce one or the other. Scientists have found that people with the long version cheat on their partners at a much higher rate – 50% vs 22% – than those with the short version. People with the long version are also more likely to take risks and face problems with addiction.


Most mammals are polygamous

Sumatran_orangutan_family_in_Toronto_ZooSource: ASAP Science, Image: Wikipedia

Only 3% of mammals are monogamous – and humans are included in that group, most of the time. What’s strange is that most other species of primates, our genetic relatives, don’t stay with the same partner for life as we do.


Social media has led to more cheating

social media iconsSource: Journal of Cyberpsychology, Behavior, and Social Networking, Image: Pixabay

The rise of social media has paralleled a rise in infidelity. Why? With sites like Facebook and Instagram, people can re-connect with old lovers, increasing the amount of affairs and breakups.


Larger testicles = more cheating?

tanuki statueSource: Psychology Today, Image: st3f4n via Flickr

Species in which males have large testicles are more likely to have promiscuous females. While promiscuity doesn’t necessarily involve cheating (especially since most of these species are non-monogamous), it’s interesting to see the correlation. Scientists believe the males developed larger testicles to store more sperm and be able to mate more frequently with the females to increase their chances of passing on their biological material.


How monogamy developed

Burying_Babies_in_China_(p.40,_March_1865,_XXII)Source: Proceedings of the National Academy of Sciences, Image: Wikimedia

Recent studies have concluded that monogamy evolved in primates due to infanticide where foreign males would kill their rivals’ infants and take over their females. Nowadays, since we’ve progressed as a species and infanticide is rather rare, we may be more likely to stray from our pairs.


Levels of the cuddle hormone affect cheating

cats cuddlingSource: ASAP Science, Image: Pixabay

Though the hormone vasopressin is primarily responsible for keeping water in the body and constricting our blood vessels, this “cuddle hormone” helps us form pair bonds. People with lower levels of vasopressin are more likely to be cheaters and feel less trust in a relationship.


Most married people will cheat

food-couple-sweet-marriedSource: Journal of Couple and Relationship Therapy, Image: Pexels

About 50% of married women and 60% of married men will have an affair while married – these numbers double what they were a decade ago.


The deeper (or higher) your voice, the more likely your partner thinks you're cheating

Grand_Gala_du_Disque_Populaire_1974_-_Barry_WhiteSource: Evolutionary Psychology, Image: Wikipedia

The deeper a man’s voice, the more likely a women is to assume he’ll cheat on her. Similarly, men assume women with higher-pitched voices are more likely to cheat on them. This is because pitch is related to our amount of testosterone and estrogen. Despite these preset instincts, women generally find men with deeper voices to be more attractive, at least for short-term relationships.


Cheating doesn't mean you're unhappy in the relationship

couple on the beachSource: WebMD, Image: Pixabay

Though it sounds contrary to common sense, cheaters often report being happy in their current relationship. Around 56% of men and 34% of women who cheated reported being “happy” or “very happy” in their relationship.


Women cheat more often while ovulating

Chris_Evans_-_Captain_America_2_press_conferenceSource: UCLA Center on Behavior, Culture, & Evolution, Image: Wikipedia

Biologically speaking, this fact about cheating falls in line with ideas on species survival. When a woman ovulates and is highly fertile, she is more attracted to men besides her partner than during the rest of the month. The exception is women with partners who are already very sexually attractive.


Cheaters do it on Wednesday afternoons

camel with humpSource: Psychological Science, Image: pavdw via Flickr

The most popular day for cheaters is Wednesday and, more likely than not, cheating happens in the afternoon when our strength to resist moral temptations is weaker than in the morning. It seems there’s another reason Wednesday is called hump day…


Christians cheat more than Jews

zionist christianSource: State of Dating Report, Image: Brother Nathanael via YouTube

Surveys done by Jdate.com and Christian Mingle revealed cheating patterns from these two religious-based dating websites. About 16% of Jewish singles reported cheating in a relationship compared to 34% of Christian singles.


Most cheaters look for affairs while at work

man-working-on-computerSource: Ashley Madison, Image: Wikipedia

Data from Ashley Madison has revealed that most (68%) of cheaters search for affairs while at work. Surprisingly, they do this for an average of 1.17 hours daily, which means some people are spending over an hour of each work day searching for a secret partner!


Men & women consider different things cheating

couple kissingSource: Evolutionary Psychology, Image: gagilas via Flickr

Most men feel sexual cheating is worse while most women feel emotional cheating is worse. Women are more likely than men to see behaviors as cheating, such as believing passionately kissing another to be cheating (90% vs 75% for men) or sending flirty text messages (68% vs 51%).


Faking orgasms could lead to infidelity

Podkowiński-Szał_uniesień-Source: Daily Mail, Image: Wikipedia

Both men and women who fake orgasms are more likely to cheat on their partner. (In contrast, the frequency of orgasm was not found to coincide or not with infidelity.) As for the numbers, women fake orgasm 20% of the time while men fake it only 5% of the time. Interestingly, men are more likely to stay with women who consistently orgasm.


Cheating leads to divorce in 65% of marriages

fighting coupleSource: Good Therapy, Image: Pexels

Most married couples break off the relationship after an affair; only 35% of couples work through the issues and remain married.


Cheating to protect offspring

ChimpanzeesSource: Proceedings of the National Academy of Sciences, Image: Wikimedia

To protect her offspring from infanticide, a female chimpanzee will often “cheat” with multiple partners. By mating with a wide group of male chimps, no male could know for sure if he was the father.


Cheaters may become more sexually active in their relationship

Das_werdenSie_ja_nachher_schon_sehenSource: Woman's Day, Image: Wikipedia

With all the sexually charged hormones flowing through their veins, cheaters often become more sexually active with their current partner, too.


Who cheats more

boy and girl about to kissSource: PLOSOne, Image: Pixabay

Women under 25 are more likely to cheat on their partner than are older women. Some reasons for cheating include a lack of intimacy and being denied their preferred sexual position.


Blondes really do have more fun

group of blonde womenSource: CheaterVille, Image: liveriga via Flickr

The statement “blondes have more fun” may have come true this time – literally. Though hair dyes were not factored in, a study by CheaterVille.com found 42% of women who cheated had blond hair. This contrasts with 23% of redheads, 20% of brown-haired and 11% of faithful black-haired women. The numbers were mostly switched for men with 40% of those with brown hair admitting to cheating compared to 23% of black-haired men, 20% of blondes, and 5% of redheads.


Most affairs are with a coworker

men-and-women-at-a-town-hall-meetingSource: Good Therapy, Image: Free Stock Photos

Most affairs – 85% of them – start in the workplace. The science behind this cheating fact shouldn’t come as a surprise – the combination of daily interaction for multiple hours and the closeness built by working on common projects leads to strong bonds and sometimes affectionate attachments.


Cheaters like to shop

shopping bagsSource: Ashley Madison, Image: Pixabay

To keep pristine looks for their lovers-on-the-side, over a third of cheating women spent double while shopping, sometimes even having a secret credit card to hide the affair. Ashley Madison found the most popular stores for cheaters are J. Crew, Macy’s, and Ann Taylor.


Rockers are more likely to cheat

Saving_Molly_-_Play_Rock_Music_Festival_2012Source: Daily Mail, Image: Wikimedia

Our musical tastes can also determine our propensity to cheat. Out of a survey of adulterers in Great Britain, 42% claimed rock n’ roll music was their favorite genre. Least likely to cheat were people who listened to rap (2%), gospel (3%), R ‘n’ B (5%), and classical (7%) music as their preferred genre. Interestingly, cheaters in Ireland were more likely to prefer country music.


A bigger penis isn't all that great

Samburu_man,_KenyaSource: PLOSOne, Image: Wikipedia

In a similarly strange fact about cheating similar to #22, men with larger penises are more likely to be cheated on by their wives. For every extra inch Kenyan men in the study had down below, the likelihood of being cheated on increased by nearly 150%. Some reasons include pain and discomfort caused during sex which prevented pleasure.


Sperm production changes for cheaters

sperm with eggSource: Daily Mail, Image: Pixabay

In one of the most bizarre and interesting facts behind the science of cheating on our list, a man’s body will subconsciously alter his sperm production if he assumes his mate is being unfaithful. Normally, human sperm contains about 40% of fighter or kamikaze sperm: aggressive swimmers used to block another guy’s sperm from inseminating an egg. If a man feels his partner is cheating, his body will produce higher percentages of these fighter sperm.

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