It’s clear that infidelity is incredibly prevalent and has been throughout recorded history.
As a culture, we love monogamy. It’s the ultimate romantic promise. The only sanctioned way we are allowed to conduct ourselves in relationships. We even sign legal contracts with the government saying as much (though one wonders why such a proclamation is necessary if sexual fidelity is supposedly so easy).
Yet, despite the romantic ideals of monogamy that are taught to us in America (and, indeed, the entire Western world), humans—both men and women—are, simply put, quite bad at monogamy.
How bad? Well, 40 to 50 percent of first marriages end in divorce (and the rate of divorce rises with each subsequent marriage) and extramarital sex is the most-cited cause of divorce across cultures. Female sexual infidelity, whether real or simply suspected, is the leading cause of spousal battering and spousal homicide. Studies have also shown that between 20 and 60 percent of all married people will cheat at least once during their relationships (researchers suspect that number is actually higher, because we frown on cheating so much as a culture, and hence tend to underestimate their indiscretions).
If studies don’t convince you, perhaps we should look no further than the 35 million members trolling AshleyMadison.com, whose tagline is “Life is short. Have an affair.” What is clear is that infidelity is incredibly prevalent and has been throughout recorded history, even though it’s also met with overwhelming disapproval. A recent Gallup poll found that Americans considered marital infidelity the worst thing a person could do, beating suicide, abortion, human cloning, and the death penalty. (Curiously, divorce was found to be the most morally acceptable thing on the list).
Why is long-term monogamy so hard for people? Let’s explore some of the facets that make up our crazy sexuality and that we are up against.
It’s counterintuitive to our nature
The argument that monogamy goes against human nature has been made countless times in books such as The Myth of Monogamy by David Barbash and Judith Eve Lipton,The Monogamy Gap: Men, Love, and the Reality of Cheating by Eric Anderson, and, perhaps the best-known (and quite compelling) Sex at Dawn: How We Mate, Why We Stray, and What It Means for Modern Relationships by Chris Ryan and Cacilda Jetha. The latter argues that our bodies are a dead giveaway for our promiscuous tendencies. Men’s penises, for instance, basically function like plungers—their uniquely shaped flared head and tapered shaft works to actively force out the sperm of other men (should there be any, you know, lying around).
Also, research has found that when men spend more time away from their partners (time that, theoretically, their partners could have spent banging the milkman), the number of sperm in their ejaculate increases the next time they have sex.
Women’s bodies also suggest that they were designed for multiple partners—with their propensity for multiple orgasms; their “large, pendulous breasts” (as Ryan is fond of describing them), which are utterly unnecessary for breastfeeding (but make great flotation devices!); and there’s even some research that suggests the reason women are more vocal during sex is to serve as a kind of mating call to attract other men to join the fray, the aural equivalent of scribbling “For a good time, call…” on a public bathroom stall. Why would our bodies have all these bells and whistles if we were mating with one person forever?
Our ancestors were sluts
As Sex at Dawn explains in great detail, our hunter-gatherer ancestors lived communally—sharing food, resources, shelter, and orgasms. Our prehistoric relatives enjoyed a much less sexually possessive culture, which benefited everyone. Men and women both enjoyed guilt-free sexual pleasure, variety, and parenting duties, like everything else, were shared, so paternity tests didn’t matter. This arrangement worked out very well until the advent of agriculture, when property rights and lineage and sexual policing became the new status quo. Ryan and Jetha also point to the bonobos, our closest primate relatives, as further evidence of our natural sluttery. The bonobos live in egalitarian and peaceful groups and have sex multiple times a day, sometimes with many partners. Doesn’t that sound awful? Put a ring on it, bonobos!
Sexual passion tends to fade over time
Falling in love is fantastic. You can’t keep your hands off the other person, everything is new and exciting, you show up late to work, not realizing the lube still stuck in your bangs. But that kind of intensity and bunny-banging intensity is unsustainable. Over time (around six months to two years), the crazy lust subsides and is replaced by a more mellow, companionate love. More than a hundred studies have documented this phenomenon, often with the sexy catchphrase “hedonic adaptation.” HA, as no one abbreviates it, basically notes that any boosts in happiness we might achieve (whether through sex, money, a new iPhone, etc.) will abate with time. Sex drive is particularly vulnerable to hedonic adaptation: Imagine watching the same porn clip 100 times. Even if it’s the hottest porn you’ve ever seen, eventually, you’ll become indifferent to its eroticism. That’s just a function of our brains.
We crave variety
This isn’t to say that we all eventually find our romantic partners boring, just that our brains are wired to crave novelty, variety, and new stimuli. This newness triggers the neurotransmitter dopamine in the brain in the same way that drugs do (or if drugs aren’t your cup of lube: gambling, eating, and shopping also work). Sexual exclusivity means we are actively fighting against these biological urges of novelty. And in women, it’s especially prevalent.
Studies show that women are far more likely than men to lose interest in sex, and to lose it faster. This is partly why the hunt for a female Viagra has been so rampant. The (kinda) good news is that long-term couples experience a second honeymoon after 18 or 20 years together (around the time the kids leave the nest, researchers posit). An empty nest bolsters surprise and novelty in a relationship once again, and all those new love feelings come back for a bonerific time to be had by all, as long as you are willing to wait a quarter of your life for it.
Is monogamy doomed?
To say that we are bad at monogamy isn’t an indictment of monogamy in general. Of course, people can and do succeed at life-long monogamous arrangements. Non-monogamous arrangements aren’t inherently better or worse than monogamous ones. And yet, just because we are monogamous with one person doesn’t negate the fact that we are still and always will be attracted to other people. As German philosopher Arthur Schopenhauer put it: “One can choose what to do, but not what to want.”
We’d do better as a culture if we exercised a little more tolerance, acceptance, and honest discussions around sex, desire, and marriage, and to be less rigid in our idealistic views of monogamy.
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This originally appeared on Alternet. Republished here with permission.