Some observers have suggested that a new discomfort with nudity might stem from the fact that, by the mid-1990s, most high schools had stopped requiring students to shower after gym class. Which makes sense—the less time you spend naked, the less comfortable you are being naked. But people may also be newly worried about what they look like naked. A large and growing body of research reports that for both men and women, social-media use is correlated with body dissatisfaction. And a major Dutch study found that among men, frequency of pornography viewing was associated with concern about penis size. I heard much the same from quite a few men (“too hairy, not fit enough, not big enough in terms of penis size,” went one morose litany). According to research by Debby Herbenick, how people feel about their genitals predicts sexual functioning—and somewhere between 20 and 25 percent of people, perhaps influenced by porn or plastic-surgery marketing, feel negatively. The business of labiaplasty has become so lucrative, she told me in an email, “that you will actually see billboards (yes, billboards!) in some cities advertising it.”As one might imagine, feeling comfortable in your body is good for your sex life. A review of 57 studies examining the relationship between women’s body image and sexual behavior suggests that positive body image is linked to having better sex. Conversely, not feeling comfortable in your own skin complicates sex. If you don’t want your partner to see you getting out of the shower, how is oral sex going to work?Maybe, for some people, it isn’t. The 2017 iteration of Match.com’s Singles in America survey (co-led by Helen Fisher and the Kinsey Institute’s Justin Garcia) found that single Millennials were 66 percent less likely than members of older generations to enjoy receiving oral sex. Which doesn’t bode particularly well for female pleasure: Among partnered sex acts, cunnilingus is one of the surest ways for women to have orgasms.

Ian Kerner, the New York sex therapist, told me that he works with a lot of men who would like to perform oral sex but are rebuffed by their partner. “I know the stereotype is often that men are the ones who don’t want to perform it, but I find the reverse,” he said. “A lot of women will say when I’m talking to them privately, ‘I just can’t believe that a guy wants to be down there, likes to do that. It’s the ugliest part of my body.’ ” When I asked 20-somethings about oral sex, a pretty sizable minority of women sounded a similar note. “Receiving makes me nervous. It feels more intimate than penetration,” wrote one woman. “I become so self-conscious and find it difficult to enjoy,” wrote another.

Mendelsund / Munday

Over the past 20 years, the way sex researchers think about desire and arousal has broadened from an initially narrow focus on stimulus to one that sees inhibition as equally, if not more, important. (The term inhibition, for these purposes, means anything that interferes with or prevents arousal, ranging from poor self-image to distractedness.) In her book Come as You Are, Emily Nagoski, who trained at the Kinsey Institute, compares the brain’s excitement system to the gas pedal in a car, and its inhibition system to the brakes. The first turns you on; the second turns you off. For many people, research suggests, the brakes are more sensitive than the accelerator.

That turn-offs matter more than turn-ons may sound commonsensical, but in fact, this insight is at odds with most popular views of sexual problems. When people talk about addressing a lack of desire, they tend to focus on fuel, or stimulation—erotica, Viagra, the K‑Y Jelly they were handing out at the New Brunswick student-health center. These things are helpful to many people in many cases, but they won’t make you want to have sex if your brakes are fully engaged.

In my interviews, inhibition seemed a constant companion to many people who’d been abstinent for a long time. Most of them described abstinence not as something they had embraced (due to religious belief, say) so much as something they’d found themselves backed into as a result of trauma, anxiety, or depression. Dispiritingly but unsurprisingly, sexual assault was invoked by many of the women who said they’d opted out of sex. The other two factors come as no great shock either: Rates of anxiety and depression have been rising among Americans for decades now, and by some accounts have risen quite sharply of late among people in their teens and 20s. Anxiety suppresses desire for most people. And, in a particularly unfortunate catch‑22, both depression and the antidepressants used to treat it can also reduce desire.

“I have a therapist and this is one of the main things we’re working on,” a 28-year-old woman I’ll call April wrote to me, by way of explaining that, owing to intense anxiety, she’d never slept with anyone or been in a relationship. “I’ve had a few kisses & gone to second base (as the kids say) and it really has never been good for me.” When we later spoke by phone, she told me that in adolescence, she’d been shy, overweight, and “very, very afraid of boys.” April isn’t asexual (she gives thanks for her Magic Bullet vibrator). She’s just terrified of intimacy. From time to time she goes on dates with men she meets through her job in the book industry or on an app, but when things get physical, she panics. “I jumped out of someone’s car once to avoid him kissing me,” she said miserably. As we were ending the conversation, she mentioned to me a story by the British writer Helen Oyeyemi, which describes an author of romance novels who is secretly a virgin. “She doesn’t have anyone, and she’s just stuck. It’s kind of a fairy tale—she lives in the garret of a large, old house, writing these romantic stories over and over, but nothing ever happens for her. I think about her all the time.”

In exchanges like these, I was struck by what a paralyzing and vicious cycle unhappiness and abstinence can be. The data show that having sex makes people happier (up to a point, at least; for those in relationships, more than once a week doesn’t seem to bring an additional happiness bump). Yet unhappiness inhibits desire, in the process denying people who are starved of joy one of its potential sources. Are rising rates of unhappiness contributing to the sex recession? Almost certainly. But mightn’t a decline in sex and intimacy also be leading to unhappiness?

Moreover, what research we have on sexually inactive adults suggests that, for those who desire a sex life, there may be such a thing as waiting too long. Among people who are sexually inexperienced at age 18, about 80 percent will become sexually active by the time they are 25. But those who haven’t gained sexual experience by their mid-20s are much less likely to ever do so. The authors of a 2009 study in The Journal of Sexual Medicine speculated that “if a man or woman has not had intercourse by age 25, there is a reasonable chance [he or she] will remain a virgin at least until age 45.” Research by Stanford’s Michael Rosenfeld confirms that, in adulthood, true singledom is a far more stable category than most of us have imagined. Over the course of a year, he reports, only 50 percent of heterosexual single women in their 20s go on any dates—and older women are even less likely to do so.

Other sources of sexual inhibition speak distinctly to the way we live today. For example, sleep deprivation strongly suppresses desire—and sleep quality is imperiled by now-common practices like checking one’s phone overnight. (For women, getting an extra hour of sleep predicts a 14 percent greater likelihood of having sex the next day.) In her new book, Better Sex Through Mindfulness, Lori Brotto, an obstetrics-and-gynecology professor at the University of British Columbia, reviews lab research showing that background distraction of the sort we’re all swimming in now likewise dampens arousal, in both men and women.

How can such little things—a bad night’s sleep, low-grade distraction—defeat something as fundamental as sex? One answer, which I heard from a few quarters, is that our sexual appetites are meant to be easily extinguished. The human race needs sex, but individual humans don’t.

Among the contradictions of our time is this: We live in unprecedented physical safety, and yet something about modern life, very recent modern life, has triggered in many of us autonomic responses associated with danger—anxiety, constant scanning of our surroundings, fitful sleep. Under these circumstances, survival trumps desire. As Emily Nagoski likes to point out, nobody ever died of sexlessness: “We can starve to death, die of dehydration, even die of sleep deprivation. But nobody ever died of not being able to get laid.”

When toys “r” us announced this spring—after saying it had been struggling because of falling birth rates—that it would be shutting down, some observers mordantly remarked that it could be added to the list of things that Millennials had destroyed.

Societal changes have a way of inspiring generational pessimism. Other writers, examining the same data I’ve looked at, have produced fretful articles about the future; critics have accused them of stoking panic. And yet there are real causes for concern. One can quibble—if one cares to—about exactly why a particular toy retailer failed. But there’s no escaping that the American birth rate has been falling for a decade.

At first, the drop was attributed to the Great Recession, and then to the possibility that Millennial women were delaying motherhood rather than forgoing it. But a more fundamental change may be under way. In 2017, the U.S. birth rate hit a record low for a second year running. Birth rates are declining among women in their 30s—the age at which everyone supposed more Millennials would start families. As a result, some 500,000 fewer American babies were born in 2017 than in 2007, even though more women were of prime childbearing age. Over the same period, the number of children the average American woman is expected to have fell from 2.1 (the so-called replacement rate, or fertility level required to sustain population levels without immigration) to 1.76. If this trend does not reverse, the long-term demographic and fiscal implications will be significant.

A more immediate concern involves the political consequences of loneliness and alienation. Take for example the online hate and real-life violence waged by the so-called incels—men who claim to be “involuntarily celibate.” Their grievances, which are illegitimate and vile, offer a timely reminder that isolated young people are vulnerable to extremism of every sort. See also the populist discontent roiling Europe, driven in part by adults who have so far failed to achieve the milestones of adulthood: In Italy, half of 25-to-34-year-olds now live with their parents.

When I began working on this story, I expected that these big-picture issues might figure prominently within it. I was pretty sure I’d hear lots of worry about economic insecurity and other contributors to a generally precarious future. I also imagined, more hopefully, a fairly lengthy inquiry into the benefits of loosening social conventions, and of less couple-centric pathways to a happy life. But these expectations have mostly fallen to the side, and my concerns have become more basic.

Humans’ sexual behavior is one of the things that distinguish us from other species: Unlike most apes, and indeed most animals, humans have sex at times and in configurations that make conception not just unlikely but impossible (during pregnancy, menopause, and other infertile periods; with same-sex partners; using body parts that have never issued babies and never will). As a species, we are “bizarre in our nearly continuous practice of sex,” writes the UCLA professor Jared Diamond, who has studied the evolution of human sexuality. “Along with posture and brain size, sexuality completes the trinity of the decisive aspects in which the ancestors of humans and great apes diverged.” True, nobody ever died of not getting laid, but getting laid has proved adaptive over millions of years: We do it because it is fun, because it bonds us to one another, because it makes us happy.

A fulfilling sex life is not necessary for a good life, of course, but lots of research confirms that it contributes to one. Having sex is associated not only with happiness, but with a slew of other health benefits. The relationship between sex and wellness, perhaps unsurprisingly, goes both ways: The better off you are, the better off your sex life is, and vice versa. Unfortunately, the converse is true as well. Not having a partner—sexual or romantic—can be both a cause and an effect of discontent. Moreover, as American social institutions have withered, having a life partner has become a stronger predictor than ever of well-being.

Like economic recessions, the sex recession will probably play out in ways that are uneven and unfair. Those who have many things going for them already—looks, money, psychological resilience, strong social networks—continue to be well positioned to find love and have good sex and, if they so desire, become parents. But intimacy may grow more elusive to those who are on less steady footing.

When, over the course of my reporting, people in their 20s shared with me their hopes and fears and inhibitions, I sometimes felt pangs of recognition. Just as often, though, I was taken aback by what seemed like heartbreaking changes in the way many people were relating—or not relating—to one another. I am not so very much older than the people I talked with for this story, and yet I frequently had the sense of being from a different time.

Sex seems more fraught now. This problem has no single source; the world has changed in so many ways, so quickly. In time, maybe, we will rethink some things: The abysmal state of sex education, which was once a joke but is now, in the age of porn, a disgrace. The dysfunctional relationships so many of us have with our phones and social media, to the detriment of our relationships with humans. Efforts to “protect” teenagers from most everything, including romance, leaving them ill-equipped for both the miseries and the joys of adulthood.

In October, as I was finishing this article, I spoke once more with April, the woman who took comfort in the short story about the romance novelist who was secretly a virgin. She told me that, since we’d last talked, she’d met a man on Tinder whom she really liked. They’d gone on several dates over the summer, and fooled around quite a bit. As terrified as she had been about getting physically and emotionally intimate with another person, she found, to her surprise, that she loved it: “I never thought I would feel that comfortable with someone. It was so much better than I thought it was going to be.”

As things progressed, April figured that, in the name of real intimacy, she should explain to the man that she hadn’t yet had sex. The revelation didn’t go over well. “I told him I was a virgin. And he broke up with me. Beforehand, I figured that was the worst thing that could happen. And then it happened. The worst thing happened.” She paused, and when she spoke again her voice was steadier and more assured. “But I’m still here.”


This article appears in the December 2018 print edition with the headline “The Sex Recession.”