Americans, especially young Americans, have seen a recent, and very significant, decline in sexual activity. Much of the commentary about this “sex recession” treats it as a puzzle, with the cause yet to be determined. Most likely, it’s a combination of multiple trends that have, in economics terms, reduced both the supply and demand for sexual relationships.

The latest data from the U.S. General Social Survey (GSS) shows that the proportion of Americans who did not have any sex in the past year has drifted upwards from under 20 percent to around 23 percent today. Somewhat more dramatically, the number of people reporting that they have sex on a weekly basis has declined from almost 50 percent to under 40 percent. But when the numbers are broken down by age and gender, the profound nature of the cultural change becomes apparent.

23 percent of 18 to 29-year-olds report having no sex in the past year. If that seems high, it is. In 2008, less than 10 percent of this age group reported being celibate. For comparison, only 7 percent of the 30–39s and 9 percent of the 40–49s were celibate last year. Even the 50–59 group is far less likely to be celibate than young adults (13 percent).

The young are having a lot less sex than older people. Instinctively — for Generation X-ers like me, at least — this matches the popular idea of a more puritanical, socially conservative generation. The young are having less sex, taking less recreational drugs, and having less fun than we did.

Many explanations for this revolve around the idea that there’s so much more to do these days. The young — it must be admitted — have far more to do than my generation did. In 1980s London, some of my lonelier and more troubled peers took to heavy drinking (bad), glue-sniffing (worse), or heroin (worse still) to escape a reality that was, it must be admitted in hindsight, dull compared to today. But while millennials are using marijuana and cocaine less than previous generations, they are using prescription painkillers more, suggesting that this generation also has voids to fill.

Breaking down the numbers further by gender reveals an even more startling trend. A decade ago, young men and women were reporting similar levels of sexual activity. Only about 8–10 percent of each group were celibate. Now, while the number of celibate young women has doubled to 18 percent, for men the proportion has tripled, to 28 percent. This is a seismic change, and one that deserves examination.

Evolution and the Sexual Revolution

The emergence of a gender celibacy gap is less a new departure than a return to an ancient way of being. To understand what is going on, it is useful to recall a couple of facts of evolutionary biology. In mammals (including humans), females tend to be more selective in their choice of mate than males. Because females get pregnant, they can reproduce much less frequently than males, who can impregnate multiple partners. Elements of this evolutionary inheritance can be seen in humans, with women often playing a selective role. In pre-agricultural times, this often meant a preference for good hunters, who could provide fresh meat. Later, as social structures evolved, many women preferred to mate with men of high social status, who would be more likely to provide well for the woman and her children.

This led to situations in which many women competed to mate with a privileged minority of men. Polygynous family structures emerged, in which one man mated with multiple women. This worked out well for most women — at least economically — and for the male elite. Additionally, it was beneficial for human evolution, as less attractive, talented, or genetically fit males reproduced less. Many ancient societies, therefore, formed three broad castes: men who mated, women, and celibate men.

With the emergence of private property and inheritance, wealth became concentrated in fewer male hands, and mating became the preserve of a privileged male elite. King Solomon for example is reputed to have had 700 wives and 300 concubines. A genetic study published in 2017 revealed the extent of the gender celibacy gap in the ancient Middle East, showing that for each man that reproduced, 17 women did.

These extreme levels of sexual inequality, and the resulting social frictions, led to the evolution of a radical new idea: monogamy. With the rise of Christianity and the Roman Empire, monogamy spread across the Western world. New taboos were introduced to maintain the new order. Promiscuous women, or women who pursued married men, were stigmatized. Women were encouraged to preserve their virginity and refuse sex until marriage. This in turn put pressure on men to propose and marry as quickly as possible. The risk of pregnancy outside wedlock, and the associated social stigma, was an effective policing tool.

And then in the 1960s, effective birth control appeared, and this changed everything. Women were liberated to sleep with who they chose without getting pregnant, and the sexual revolution commenced. Sex became freer and easier, and this newfound sexual freedom benefited women and men alike. The old stigmas against promiscuous women remained, but these have eroded in the subsequent generations, seen in criticism of “slut-shaming” and similar efforts.

But when it comes to sex, human biology has not significantly changed. Women are still fussier than men in choosing a mate, for good evolutionary reasons. The new sexual freedom would inevitably restore some level of sexual inequality, in which less desirable men would lose out. Accompanying this change is the rise of the self-labeled “incel” (involuntarily celibate) phenomenon, online communities of men who bemoan the fact that they cannot find sexual partners. These communities often express angry, misogynistic attitudes, and harbor a deep sense of unfairness, as if they’re somehow entitled to sex with women.

But however their grievance is expressed, it does appear partially rooted in a reality in which some men are losers in the mating game. Studies indicate poor men are far more likely to be single than wealthier men. GSS data showing that celibacy among young men leapt from around 10 percent to almost 30 percent between 2008 and 2018 underscores the claim that sexual relationships may have moved beyond the reach of many American men.

Pornography

If we think of mating like a market, the above explains the documented decline in sexual activity as a reduction in supply (of female partners to less-suitable young men). But another revolution, this one in the past decade, has reduced demand: free, easily accessible pornography.

I witnessed this change first-hand. In 2004, I launched a commercial pornography site, which sold streaming movie rentals. This business grew rapidly, until October 2007, where we saw sales dip slightly. And then sales dipped again in November, and in December, and every month thereafter. The culprit was a new breed of website — the “tubes” — offering free streaming pornography. The established industry could not compete, and imploded. And because porn no longer cost money to consume, it could be freely accessed by exactly the demographic with the highest sex drive: young men, who may not have had the means to buy pornography before the tube sites appeared.

Porn has already been strongly linked with a steep fall in sexual violence among young men. Now it seems pornography has caused a more general decline in sexual interest among young men, which is leading to higher rates of celibacy among that group.

And it’s not just America. In Japan, for example, the combination of more entertainment options and more easily accessible pornography has led to the rise of a new class of young men known as “herbivores” (i.e. men who don’t want to hunt).

This demand and supply-driven decline of sexual relationships among young adults will likely play out in lower rates of marriage and a continued reduction in the birth rate in the United States and other developed countries. Whether this trend is seen as positive or negative is largely subjective. Sex is a beautiful thing, and also the source of many of society’s deepest problems.