A new study published in PNAS explored the cognitive, physical and personality traits shared by people who experience lifelong sexlessness. The results draw a somewhat counterintuitive picture. The people most closely linked to sexlessness were highly educated, less likely to drink alcohol or use drugs and more likely to report feeling nervous and unhappy.

I recently spoke to the corresponding author of the paper, Dr. Karin Verweij — behavioral geneticist and professor at the University of Amsterdam — to understand the phenomenon of sexlessless and the results of her study better. Here’s a summary of our conversation.

What inspired you to investigate sexlessness in your research?

Sexual relationships play a major role in people’s lives and can affect people’s mental health. Yet, there has been surprisingly little research on people who never have sex. 

Previous studies focused mostly on young adults, heterosexual encounters and a limited set of traits. From an evolutionary perspective, this topic is also fascinating, as lifelong sexlessness means not reproducing and not passing on one’s genes, which is fundamental to evolution.

We saw an opportunity to use very large and deeply characterized datasets, including UK Biobank with ~400,000 people, to examine the psychological, social and genetic factors associated with lifelong sexlessness.

Could you paint us a picture of a lifelong sexless individual informed by the findings of your study?

About 1% of the population reported never having had sex, and this proportion was the same for men and women. There isn’t a single “type” of sexless individual, but certain patterns emerged. 

We saw that this group is on average more highly educated, less likely to drink alcohol or use drugs and more likely to report feeling nervous, lonely and less happy. Sexless men, in particular, tended to have lower physical strength (e.g. grip strength) and were more often living in regions with fewer women. 

For both men and women, sexlessness was more common in areas with higher income inequality. Genetic analyses generally mirrored these differences: sexlessness showed positive genetic correlations with intelligence and education, and negative correlations with substance use. Overall, the picture is one of subtle differences across many domains, rather than a single defining characteristic.

Could you unpack the curious link between sexlessness and low alcohol and drug intake for us?

Yes, we found a clear pattern, both phenotypically and genetically. Individuals who never had sex were less likely to smoke, drink or use cannabis. We can’t determine the reasons for this from our data, but we can speculate.

Alcohol and drug use often create social situations where sexual encounters are more likely to happen, so people who use these substances less may simply have fewer opportunities to meet partners in such contexts. Personality traits like lower risk-taking and extraversion probably also play a role. 

Why is it that high intelligence is so closely linked to sexlessness?

We observed quite strong positive correlations between sexlessness and IQ, both genetically and phenotypically. This was striking because intelligence and resources are often thought to increase attractiveness. 

Again, we can’t determine the reasons for this association from our data. Possibilities include lifestyle choices — people with high educational potential may invest heavily in careers and delay or deprioritize relationships and this pattern can persist later on. 

It’s also possible that young adults with high educational potential avoid relationships that might interfere with their plans. These are speculations; we don’t have direct evidence for the underlying mechanisms. 

Does your study have any practical takeaways for people who might struggle with loneliness and sexlessness?

The study is descriptive only and shows differences on a group level. We highlight that sexlessness reflects a complex interplay of social, psychological, biological and regional factors.

A takeaway really depends on the person — there’s no one-size-fits-all solution. It’s important to stress that being sexless is not inherently negative; many people live happy and fulfilling lives without sexual activity.

For those who find sexlessness unwanted, help might focus on addressing loneliness, social connection and engagement, rather than sex itself. Building social connections, and seeking professional support if needed, can be helpful steps.

Was there anything in the results of the study that took you by surprise?

Yes. One striking finding was that about 1% of both men and women reported never having had sex, but the characteristics linked to sexlessness looked quite different for men and women, both phenotypically and genetically. 

The genetic correlation between male and female sexlessness was only 0.56, which is low compared to most behavioral traits. This shows that, although the prevalence is the same, the underlying factors partly differ between men and women.

We were also surprised by the strong genetic links with intelligence and the clear differences in substance use patterns.

Could your views on sex be trapping you in an unwanted sexless lifestyle? Take this science-backed test to learn more: Brief Sexual Attitudes Scale