The share of American adults having no sex in the past year reached an all-time high in 2018, an intimate survey revealed Friday, and many of those missing out are men in their 20s.

An analysis of new research data by The Washington Post reveals a battle of the sexes, with 18 percent of the women between the ages of 18 and 30 reporting no sex in the past year—but 28 percent of men.

Male millennials are often portrayed in popular culture as the most sexually active—or at least the most sexually eager—and the news prompted a surprised reaction on social media.

"Reasons why likely include a greater preference for video games and for porn," tweeted US psychologist and practicing family doctor Leonard Sax, who was speaking generally about the issue before the survey's release.

"Young men tell me that the video games, and the porn, are vastly better today than they were 20 years ago."

The largest disparity is between age groups, with only seven percent of thirtysomethings reporting a barren year in the love stakes.

The figure is as impressive among frisky fortysomethings—only nine percent said they'd struck out in 2018—and those aged between 50 and 59. Just 13 percent of this group say they didn't get lucky last year.

For those 60 and older, the share reporting no sex over the past year has remained steady around 50 percent.

But the overall 23 percent figure—up from 19 percent two decades ago—paints a picture of a nation growing gradually but steadily less amorous.

Celibacy as a corrosive force hit the headlines recently with emergence of the "incel" online subculture of angry young men unable to find sexual partners—with the movement linked to several mass shootings in the US.

But it has had its high-profile champions too: Andy Warhol, J Edgar Hoover, Isaac Newton and Joan of Arc were all said to be proud celibates.

The data on America's bedroom habits was collected for the General Social Survey conducted by the NORC research organization at the University of Chicago and analyzed by the Post.

The newspaper said its analysis underscored a three-decade trend line marked by an aging population and higher numbers of unattached people.