NEW YORK — “Everyone is drinking, peering into their screens and swiping on the faces of strangers they may have sex with later that evening.”
That portrayal of app-abetted, casual-sex-having millennials in the wild, from a 2015 Vanity Fair article by the journalist Nancy Jo Sales, is far from unusual. Hookup culture and the smartphone apps that make it easy to find partners are commonly portrayed as having fueled a rise in promiscuity among young adults.
But a study published this week said this sex-charged picture was not a reality for a significant percentage of young millennials.
The study, published Tuesday in the journal Archives of Sexual Behavior, found that more young people are living sexless existences than their counterparts born in the 1960s did at the same age.
To be clear, this does not mean that the vast majority of young millennials are having less sex than of previous generations did. It simply means that the portion of people born in the early 1990s who are not having sex is larger than a similar cohort from decades earlier.
“People are still getting it on,” said the study’s lead author, Jean Twenge, a psychology professor at San Diego State University.
She noted that overintepretation by the public and the news media was a common problem with studies like hers.
“Just like it’s not true that millennials are all promiscuous people who are on Tinder all the time, it’s also not true that all millennials are sexless and just watching porn in their moms’ basements,” she said.
Justin R. Garcia, an evolutionary biologist and sex researcher at the Kinsey Institute at Indiana University, seconded that point, saying that while the increase in young adults who are sexually inactive was compelling and statistically significant, there was a broader takeaway.
“The data also shows that 85 percent of young people in their sample are sexually active in the last 12 months,” he said. “The vast majority of American youth are sexually active, and that’s the reality we need to take seriously.”
The paper, part of a series of three reports that Twenge and her colleagues have published or plan to publish about young people’s sexual behavior, relied on the General Social Survey, a nationally representative survey of American adults that has been taken regularly since 1972. (The researchers used annual and biennial surveys taken from 1989 to 2014.)
It found that about 6 percent of young adults — defined as being between the ages of 20 and 24 — who were born between 1965 and 1969 reported having no sexual partners after age 18. By contrast, 15 percent of young adults born between 1990 and 1994 reported having no sexual partners after turning 18.
The increase in sexual inactivity was far more notable among women than men, and was only significant for those without a college education, the paper said. The phenomenon was not observed among survey participants who had attended college.
The trend of more sexless lives was also nonexistent among black Americans, according to the paper, which did not break out information about other racial groups. The trend was “larger and significant” among those who attended religious services; it was present but “not significant” among those who did not.
The paper’s findings were echoed by the national Youth Risk Behavior Survey, conducted by the Centers for Disease Control and released in June, which found that the number of sexually active high schoolers had decreased from 1991 to 2015.
Twenge’s study acknowledges several of its own limitations, including that participants might have varied interpretations of the phrase “had sex with.”
“It is possible that earlier generations counted any sexual activity as sex,” the study says, “thus increasing their counts of partners, whereas younger generations, perhaps influenced by abstinence-focused education and purity pledges, may see sex as including only vaginal-penile penetration, thus leading them to report lower numbers of sexual partners.”
But it calls that possibility “unlikely,” citing a paper about the changing sexual habits of first-year university students at a school in Sydney, Australia.
The survey data includes homosexual sex, Twenge said. She said that reports of same-sex activity have become more common than in earlier eras.
The paper discusses some factors that Twenge thinks might be responsible for the rise in sexual inactivity, including the slowed development of adolescents, an increase in abstinence-only sex education and the unequal outcomes created by new technology such as Tinder.
But she acknowledged that “we can’t say for sure” that any of those causes were at play in the data revealed by the paper.
Garcia said that it was important to “think critically about the claims we’re making and the available data on patterns of sexual behavior over time,” citing media headlines that sought to investigate what the paper revealed about hookup behavior or casual sexual behavior.
“The methodology of the paper, which was sound, looked at generalized sexual behavior. It doesn’t really say anything about whether its relationship sex or casual sex,” he said. “Some of those inferences that are being made are hypotheses, and the data doesn’t really allow one to clearly answer some of those questions.”