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, a 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 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 relied on the General Social Survey, a nationally representative survey of American adults done regularly since 1972. (The researchers used annual and biennial surveys taken from 1989 to 2014.) It found that about 6 percent of young adults — ages 20 to 24 — who were born between 1965 and 1969 reported having no sexual partners after age 18. But 15 percent of those born between 1990 and 1994 reported having no partners after turning 18.

The increase in inactivity was more notable among women 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 blacks, according to the paper, which did not break out data 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 findings were echoed by the national Youth Risk Behavior Survey, done 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 “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.’’

But it calls that possibility “unlikely.’’ The survey data include homosexual sex.