In bedrooms all over England, things have changed since 2001. According to analysis released Tuesday in the BMJ, couples in the UK just aren’t getting it on like they used to in the early 2000s. This represents a dearth in sexual activity that scientists say is just as “interesting” as it is “unexplained.”

This study, authored by Kaye Wellings, Ph.D., a professor at the London School of Hygiene and Tropical Medicine, uses survey data from over 34,000 British men and women aged 16 to 44, to show that less than 50 percent of men and women had sex at least once per week in 2012.

Digging deeper, she found that the amount of sex people report per month has been declining since 2001 in all age groups except males between 16 and 24. The steepest declines, she notes, happened among couples 25 years old and older.

The change has occurred rapidly. In 2001, 23 percent of women reported having no sex in the past month. By 2012, that number increased to 29.3 percent. Among men, 26 percent reported having no sex in the past month in 2001, and by 2012 that increased to 29.2 percent.

Most important is the fact that these people were not avoiding sex. In fact, Wellings found that they want to be having more sex. The mismatch between the amount of sex people are having and the amount of sex they want to have, the paper notes, may be driven in part by the “pace of modern living.”

“In The Past Decade Sexual Frequency is Declining”

The survey indicates that people want to be having sex more often now than they did in the past. In 2001, 39.1 percent of women surveyed said that they would prefer having sex more often, but by 2012, that increased to 50.6 percent. Ditto in men: 51.2 percent of men said they wanted to have more sex in 2001, but by 2012 that number reached 64.3 percent.

And yet, Wellings found that actual sexual activity declined in that period. If people want to be having more sex, what exactly is getting in the way?

In an email to Inverse, Wellings proposed one theory. The current sex-deprived generation — those 25 and up — are too swamped with responsibility to get it on.

“These are the cohorts of men and women who, having started their families at older ages than previous generations, are often juggling childcare, work and responsibilities to parents who are getting older,” Wellings said.

But the frantic balance of work and childcare may not be the only driving force behind the decline of sexual life. For one, 25-year-old couples in the UK are far from alone in this trend, adds Dr. Peter Leusink, a general practitioner and sexologist at Radboud University Medical Center and the author of a commentary published alongside Wellings’ article.

“In general, the findings are comparable, the UK doesn’t perform worse,” he tells Inverse. ”One can say with a high degree of certainty that in high income countries in the past decade sexual frequency is declining.”

Why Are People Having Less Sex?

Both Wellings and Leusink point to the idea that sexual frequency isn’t necessarily representative of a happy relationship, especially the new data doesn’t cover other physical ways people display intimacy. Still, Leusink thinks these declines could indicate larger trends in society that are pushing us apart.

"I think that changes in frequency might be a signal that something is going on.”

“I think that changes in frequency might be a signal that something is going on,” says Leusink. “But, knowing what exactly is going on needs more research. Sex is more available since the internet, we do not need a partner for that; the way we communicate has changed since social media; our society is more individualized; all these reasons might apply.”

Whether social media or an “individualized society” is to blame, there is evidence elsewhere showing that people in general are lonelier now than ever. In the UK in particular, data shows that people are finding it hard to connect with others. Faced with loneliness that takes a toll on mental health, the country has recently appointed a minister for loneliness.

The link between trends in loneliness and declines in sexual activity is beyond the parameters of the current study, but both emerging patterns support a point Wellings makes in her conclusion: that there are new barriers to human connectedness that have arisen in the past ten years, which may be impacting sexual activity.

“Should frequency of sexual contact serve as a barometer for more general human connectedness,” Welling and her co-authors write, “then the decline might be signalling a disquieting trend.”

Partial Abstract:

Participants — 18 876 men and women aged 16-59 and resident in Britain were interviewed in Natsal-1, completed in 1991; 11 161 aged 16-44 years in Natsal-2, completed in 2001, and 15 162 aged 16-74 years in Natsal-3, completed in 2012. Comparisons of actual and preferred sexual frequency in men and women aged 16-44 (the age range common to all surveys) between the three surveys. Factors associated with sexual frequency of at least once a week were examined using Natsal-3 data.

Main outcome measures — Sexual activity in the past month; frequency of sex in the past month; preferred frequency of sex.

Results — Median number of occasions of sex in the past month was four in Natsal-1 and Natsal-2 and three in Natsal-3 among women; and three in Natsal-1, Natsal-2, and Natsal-3 among men. The proportion reporting no sex in the past month fell between Natsal-1 and Natsal-2 (from 28.5% to 23.0% in women and from 30.9% to 26.0% in men) but increased significantly in Natsal-3 (to 29.3% in women and 29.2% in men). The proportion reporting sex 10 times or more in the past month increased between Natsal-1 and Natsal-2, from 18.4% to 20.6% in women and from 19.9% to 20.2% in men, but fell in Natsal-3, to 13.2% in woman and 14.4% in men. Participants aged 25 and over, and those married or cohabiting, experienced the steepest declines in sexual frequency (P values for interaction <0.05). Alongside the declines in sexual frequency, there was an increase in the proportion reporting that they would prefer sex more often. Age adjusted odds ratios showed that men and women in better physical and mental health had sex more frequently, as did those who were fully employed and those with higher earnings.