Some People Are Born to Infidelity! Does Your Partner Have the "Cheating Gene"?

In Eileen Chang's classic novel Red Rose, White Rose, she mocked men who are fickle in love:

"Maybe every man has had two such women—at least two. Marry a red rose, and after a while, the red is a spot of mosquito blood on the wall while the white is still 'moonlight beside the bed.' Marry a white rose, and the white is a grain of rice stuck to a shirt, while the red is a crimson cinnabar mole over the heart."

Perhaps you once swore you would never change, but as the years go by, can you truly guarantee you will never stray?

Between 2000 and 2015, a research team from the Institute of Sexology at Renmin University of China conducted random sampling surveys of the national population, which included detailed data on extramarital sexual behavior. The findings revealed that over those 15 years, the proportion of both men and women having extramarital affairs steadily increased.

From 2000 to 2015, the male infidelity rate jumped from 11.8% to 34.0%, while the female infidelity rate rose from 4.1% to 13.4%. By 2015, roughly 1 in every 3 husbands and 1 in every 7.5 wives had experienced an extramarital affair.

No matter how many vows were exchanged, the data confirms that infidelity rates in modern society are on the rise. Even the most firm and sweet promises may fail to resist the restless impulses inside many hearts.

Why do some people find it so hard to control themselves, choosing infidelity in pursuit of thrill and excitement?

From a scientific perspective, human bodies do carry certain "restless factors"!

1. Is Infidelity Human Instinct?

In fact, infidelity is widespread across most animals in nature.

To better pass on their genes, animals do everything possible to find higher-quality mates. If optimal mates aren't available within their primary partnership, they will secretly mate with other high-quality individuals outside the social pair bond to secure better genetic outcomes—a direct result of natural selection.

Furthermore, like all mammals, humans naturally crave novelty. The dopamine surge triggered by a new, unfamiliar partner far exceeds that produced by a familiar one.

In biology, there is a famous phenomenon known as the "Coolidge Effect." Scientists experimenting with rats found that male mammals eventually grow sexually fatigued with a single partner, but will immediately regain intense sexual drive when introduced to a new female.

This effect goes a long way toward explaining why some middle-aged men seem sluggish and uninterested in front of their wives, yet show boundless energy with a new partner...

It seems the "infidelity program" really is embedded in the human brain. But why are some people able to hold the ground of reason, while others remain fickle and easily swayed?

2. Fidelity or Infidelity: It Might Be in Your Genes!

(1) "Cheating Genes": The Restless Factors Within Us

1. The DRD4 Gene In 2010, a research team at the State University of New York surveyed 180 young men and women and identified a gene variant linked to infidelity: DRD4.

Research showed that about 25% of people carry this "love cheater" gene variant, making them more than twice as likely to engage in unfaithful behavior. Among participants carrying the DRD4 mutation, 50% had betrayed a partner, and they were significantly more prone to one-night stands. In contrast, only 22% of those without the mutation had cheated.

Dopamine functions as the brain's reward mechanism, creating feelings of pleasure. DRD4 is closely linked to dopamine "bursts" triggered by high-risk, high-reward, and unpredictable behaviors.

The study also noted that carriers of this specific D4 receptor mutation are not only more prone to cheating and casual hookups, but are also more susceptible to gambling and alcohol addiction. This suggests that infidelity can be as addictive as gambling or alcoholism—once it happens, it is far easier to repeat.

2. The V1aR Gene A study published in Science magazine compared prairie voles (which are strictly monogamous) with their close relatives, mountain and meadow voles (which engage in continuous promiscuity).

Researchers discovered that the striking behavioral difference stemmed from DNA variations—specifically, vast differences in the expression levels of the V1aR gene in their brains.

This finding extends to humans as well: men carrying double copies of a specific V1aR gene variant face a 34% rate of marital crisis or divorce, compared to only 15% among those with a single copy.

3. The AVPR1A Gene Every person inherits two copies of the AVPR1A gene—one from each parent—resulting in various genetic combinations. Subtle genetic variations across these combinations can heavily influence behavior, with certain combinations linked to promiscuity.

A research team at the University of Queensland in Australia analyzed the DNA and relationship histories of 7,378 men and women. They found that 6.4% of the women had been unfaithful, and a large proportion of them carried a mutated version of the AVPR1A gene. Interestingly, this gene variation did not appear to affect male cheating behavior in the same way.

(2) Beyond "Cheating Genes": The "Marital Harmony Gene"

Fascinatingly, human DNA contains not only "cheating genes" but also "marital harmony genes." People carrying this genetic mutation report greater relationship satisfaction and lower divorce rates.

In February 2021, researchers at the University of Arkansas published a study on this "marital harmony gene" in Scientific Reports.

Tracking 71 newlywed couples, the study revealed that individuals with the CC genotype at the rs3796863 locus of the CD38 gene demonstrated higher levels of gratitude, trust, and forgiveness toward their partners, as well as higher overall marital satisfaction, compared to those with AC or AA genotypes.

3. Is Gene Predisposition an Excuse for Cheating?

Scientists have traced the biological origins of infidelity. On the surface, it might seem like humans are mere playthings of their DNA, that cheating is "beyond our control," or that infidelity is an incurable human trait. Some commercial companies have even launched "infidelity gene testing kits" off the back of these findings...

But can genetics ever serve as a legitimate excuse for cheating?

In reality, genetics is simply a window through which we understand how biology influences behavior. Carrying these genetic variants does not guarantee a person will engage in one-night stands or infidelity.

Human behavior is heavily shaped by personal consciousness, self-control, and environmental factors. From ancient promiscuity to feudal polygamy, and finally to modern monogamy, every evolutionary step in human relationships has been built on civilizational progress and mutual respect.

Genes are never an excuse for infidelity; humans have the power to master their instincts. Honoring the promises we make to one another is the true foundation of human dignity.

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