Okay, this might ruffle a few feathers, but stay with me.
Contrary to popular belief, new research suggests that women may be just as likely—if not more likely—to cheat than men. Not because of stereotypes, but due to our biology and genetics.
This challenges a long-held cultural assumption: that men are hardwired to cheat due to their evolutionary drive to “spread their seed,” while women, biologically speaking, are more selective and focused on securing a provider for long-term stability.
But according to emerging scientific studies, the real story may be far more nuanced—and it all comes down to hormones and genetics.
The Hormone Behind the Urge: Vasopressin
In an eye-opening op-ed titled “Infidelity Lurks in Your Genes”, psychiatrist Richard A. Friedman introduces us to the hormone vasopressin, which plays a big role in social bonding, empathy, and sexual behavior.
A recent study conducted by psychologist Brendan P. Zietsch from the University of Queensland explored the connection between infidelity and receptor genes tied to hormones like vasopressin and oxytocin.
His team looked at thousands of participants who had been in relationships for at least a year. What they found was fascinating: a genetic mutation in the vasopressin receptor appeared to be more common in women who admitted to infidelity.
In fact, five specific genetic variants were discovered only in women who had cheated during the course of the study.
What the Numbers Say
Statistically, 6.4% of women and 9.8% of men in the study reported having had two or more sexual partners that year. While men still led in numbers, the genetic link to infidelity was found only in women, which raises an interesting question:
Is infidelity in women influenced more strongly by biology than we once thought?
It’s not about blame. It’s about understanding behavior, and how much of it might be driven by internal factors we rarely consider — like the wiring of our own brains.
The Emotional Power of Oxytocin
Most of us have heard of oxytocin, often dubbed “the love hormone.” If not, look it up — or better yet, read Louann Brizendine’s The Female Brain for an in-depth look at how oxytocin affects everything from trust to orgasm.
Oxytocin is released during moments of intimacy, especially during sex, and it fuels emotional bonding — often more intensely for women.
This hormonal response is partly why casual sex may feel more emotionally complex for women. It also explains why many women form emotional attachments through physical connection — even when they didn’t plan to.
So, Why Do Some Women Cheat?
Even though evolutionary psychology traditionally framed men as the “cheaters” and women as the “nurturers,” these new insights suggest a much more complex story.
Studies also show that some women carry a gene variation that, when interacting with vasopressin, may increase the likelihood of straying from a partner — not necessarily because of emotional dissatisfaction, but because of how the brain responds to bonding, stress, or novelty.
Another study from Hasse Walum at Sweden’s Karolinska Institute found that variations in the oxytocin receptor gene were strongly linked to marital dissatisfaction in women.
That’s right — the presence of certain genetic markers was associated with lower fondness or increased conflict in long-term relationships. And in men, a variation of the vasopressin gene was tied to similar outcomes.
Even the Animal Kingdom Is on to Something
Let’s talk about voles. Yes — rodents. In a study by neuroscientist Thomas R. Insel, two closely related species of voles showed vastly different mating behaviors based on how vasopressin affected their brains.
- Prairie voles are monogamous and form strong pair bonds.
- Montane voles, however, are promiscuous and don’t tend to stick around.
The difference? Where their vasopressin receptors are located in the brain.
In prairie voles, these receptors are near the brain’s reward center — making monogamy feel good. In montane voles, the receptors are closer to the amygdala, the area tied to fear and anxiety — potentially pushing them away from long-term bonding.
Humans aren’t voles, of course. But the takeaway is powerful: small genetic differences can lead to big behavioral changes.
The Takeaway: Biology Isn’t Destiny — But It Does Matter
Does this mean women are genetically “wired” to cheat? Not exactly. But it does mean that our biology may influence our behaviors more than we realize, especially when it comes to intimacy, attachment, and desire.
Of course, there are countless reasons why someone might cheat — emotional neglect, boredom, unmet needs, revenge, opportunity, and more. Many of these factors are environmental and psychological, not just hormonal.
But what the research does suggest is that understanding your own hormonal and genetic makeup may help you better understand your emotional and sexual patterns.
So, Should You Get Your Genes Tested?
Not necessarily. You don’t need a DNA test to know if you’re fulfilled in your relationship — or if something’s off.
But learning about how hormones like vasopressin and oxytocin shape our experiences is a powerful way to be more intentional about who we choose, how we connect, and what we need from our relationships.
At the very least, it reminds us that love and lust aren’t always logical — and that even in a world of dating apps and modern romance, some of our deepest urges might be rooted in something much older than we think.
