About one percent of the adult population has never had any form of sexual experience. Not once.
A new study has taken the most serious look yet at what drives lifelong sexlessness, and the findings are genuinely surprising.
The study, published in the Proceedings of the National Academy of Sciences, found that genetics, personality, intelligence, physical traits, and local economic conditions all play measurable roles in whether a person lives without ever having sex.
One of the most counterintuitive findings in the dataset is that the genes most strongly associated with sexlessness are the same genes associated with higher intelligence and greater educational achievement.
That was not what anyone expected.
It overturns one of the foundational assumptions of evolutionary psychology, and it raises questions that researchers are still struggling to fully answer.
How the Study Was Conducted
The research was led by Dr. Abdel Abdellaoui, a geneticist at the Department of Psychiatry at Amsterdam University Medical Center, alongside an international team of behavioral geneticists and social scientists.
The primary dataset came from the UK Biobank, one of the largest and most detailed health databases in the world, containing genetic, medical, and lifestyle information on approximately half a million British residents.
The team analyzed data from more than 400,000 UK participants between the ages of 39 and 73, a deliberate choice, because studying people past typical reproductive age means the researchers were capturing true lifetime sexlessness rather than simply a delayed start.
A secondary dataset of approximately 13,500 Australians aged 18 to 89 was used to independently validate the genetic findings.
Participants were asked directly whether they had ever had vaginal, oral, or anal intercourse.
Of the more than 400,000 UK respondents, 3,929 individuals, roughly one percent, said they never had.
That group included 2,068 women and 1,861 men.
The research team then examined 251 different traits and characteristics across this group, ranging from mental health and personality measures to physical strength, education level, substance use, social habits, and regional economic data.
They also conducted a genome-wide association study (GWAS), scanning more than 10.6 million genetic variants across the genome to identify which DNA patterns were associated with sexlessness.
As Technology Networks reported, the researchers found that common genetic variants explained roughly 17 percent of the variation in male sexlessness and 14 percent in female sexlessness.
The genetic overlap between the male and female patterns was moderate, at around 56 percent, suggesting that while many of the same underlying genes are at work in both sexes, meaningful biological differences remain.
Findings From the Study
The results painted a complex and layered picture.
Across both men and women, sexlessness was consistently associated with greater social withdrawal, less frequent contact with friends and family, a lower likelihood of having a close confidant, and significantly higher levels of loneliness and unhappiness.
Sexless individuals were also less likely to drink alcohol, smoke cigarettes, or use cannabis, a finding that appeared consistently across both the phenotypic data and the genetic analysis.
They were more likely to report feeling nervous, and they scored lower on measures of extraversion, the personality dimension that drives social engagement and risk-taking.
For men specifically, the study found additional physical dimensions.
Lower grip strength, leaner arm muscle mass, and wearing glasses from an early age were all significantly associated with sexlessness in men, but not in women.
The researchers noted that focus groups in earlier studies had identified a consistent pattern: people who wore glasses as children reported being called “nerds” or “geeks” during adolescence and perceived themselves as unattractive during those critical early years of social and romantic development.
Wearing glasses as an adult, interestingly, showed no such association.
The implication is that adolescent social experiences, and the self-image formed during them, may have lasting effects on intimate life that extend well into adulthood.
The geographic dimension of the findings was also striking.
Sexless men were significantly more likely to live in regions where women were fewer relative to men, a direct measure of what researchers call the local “mating market.”
And for both men and women, sexlessness was more prevalent in regions with higher income inequality, as measured by the Gini coefficient, a standard economic measure of wealth disparity.
As Psychiatric Times reported, these social ecology findings echo earlier, smaller studies linking economic marginalization to reduced romantic opportunity, and raise uncomfortable questions about the relationship between financial inequality and intimate isolation.
The Intelligence Paradox: Why Smarter Genes Predict Less Sex
The single most striking finding in the entire study is one that the researchers themselves described as difficult to explain.
Genes associated with higher childhood IQ, greater educational attainment, and higher socioeconomic status were all significantly and positively correlated with sexlessness.
In other words, the genetic factors that make a person more likely to be educated, intelligent, and financially successful are also factors that make them somewhat more likely to have never had sex.
That appears to contradict one of the most deeply held assumptions in evolutionary biology: that intelligence and resources are attractive traits that increase mating success.
As the researchers wrote in the published paper, “obvious explanations for this, which apply to both men and women, are not apparent to us.”
One tentative explanation the team offered is that young adults with strong educational and professional potential may be more likely to prioritise those ambitions over seeking intimate relationships, forming habits and patterns of social withdrawal that extend into later life.
Another possibility is that the genetic overlap reflects a broader personality profile: highly conscientious, internally focused individuals who are less drawn to the social environments where romantic encounters typically happen.
What makes this finding particularly significant is that it directly challenges the sexual selection theory of human intelligence, the idea that our extraordinary cognitive abilities evolved partly because smarter individuals were more attractive to potential mates.
If higher intelligence genetically predicts a greater chance of sexlessness, that theory becomes much harder to defend.
As lead author Abdellaoui told Technology Networks, the genetic associations found in the study overlapped significantly with “a higher education and IQ, less substance use, higher autism and anorexia risk, and lower ADHD, anxiety, depression and PTSD risk.”
That cluster of traits, considered together, begins to look less like a random collection of characteristics and more like a coherent psychological profile.
The Nerd Effect: Social Identity and Sexual Opportunity
The researchers were candid about a pattern running through their data that mapped onto a recognisable social stereotype.
When they considered the full picture, introverted, academically strong, physically less robust, socially withdrawn, nervous, less likely to drink, more likely to be on the autism spectrum, and wearing glasses in childhood, it assembled into what they explicitly described in the paper as resembling the cultural archetype of the “nerd.”
That word carries a specific social history.
People who fit that profile during adolescence frequently report being perceived as romantically unattractive during the years when patterns of social and intimate behavior are being established.
The researchers noted that early adolescent experiences of exclusion or romantic failure can set trajectories that persist for decades, not because those individuals are inherently unable to form relationships, but because the social pathways through which romantic connections are typically made were less accessible to them at a formative stage.
This does not mean intelligence or introversion causes sexlessness in any simple sense.
It means that a set of traits, some genetic in origin, interact with social environments in ways that can reduce romantic opportunity, particularly during adolescence and early adulthood when those patterns are most strongly shaped.
Alcohol, Risk-Taking, and the Social Architecture of Sex
One of the more nuanced threads in the research concerns the relationship between substance use, risk-taking, and sexual initiation.
Sexless individuals were consistently less likely to drink alcohol, smoke, or use cannabis, and this pattern showed up in the genetic data as well as the behavioral data.
The researchers offered several possible explanations for this connection.
One is straightforward: alcohol and social substances lower inhibitions and are typically consumed in social settings where potential partners are met.
People who are less drawn to those environments, whether by personality, genetics, or circumstance, have fewer natural opportunities for the kinds of encounters that lead to sexual experience.
Another explanation lies in the genetics of risk-taking and pleasure-seeking.
The same genetic variants associated with a willingness to take risks and seek novel experiences tend to correlate with both substance use and more active romantic and sexual lives.
People whose genetic profile tilts away from novelty-seeking and toward caution and restraint may be less inclined to pursue the mating game in the first place.
As Psychology Today noted in its coverage of the findings, this points toward a picture where sexual inactivity is often not a single choice but an accumulation of smaller tendencies, toward social withdrawal, away from risky environments, and toward intellectual rather than social engagement, all of which compound over time.
The Role of Geography and Economic Inequality
One of the most sociologically significant findings in the study was the relationship between sexlessness and the economic conditions of where people live.
The data showed that sexlessness was significantly more common in regions with higher income inequality, a result that held for both men and women and replicated consistently across different analytical approaches.
This finding matters for reasons that go beyond individual biology.
It suggests that the social and economic structures of a community directly shape intimate life in ways that are measurable at a population level.
Higher income inequality has been linked in other research to reduced social trust, increased social anxiety, and greater barriers to forming stable relationships, all of which could plausibly reduce romantic and sexual opportunity for those at the lower end of the economic spectrum.
For men specifically, living in areas where women were proportionally fewer was also a significant independent predictor of sexlessness.
The researchers noted that this finding strengthens earlier, more indirect research linking male romantic isolation to the geography of mating markets, and raises serious questions about how demographic imbalances created by urbanisation, migration, and economic sorting contribute to population-level patterns of sexlessness and the social tensions that can follow from them.
What the Genetics Actually Mean, and What They Don’t
The researchers were careful throughout the paper to emphasise the limits of what their genetic findings prove.
Professor Karin Verweij, co-senior author and professor of Genetics in Psychiatry at Amsterdam UMC, was direct in the official institutional statement: “It is emphatically not about a ‘gene for virginity.’ Our results show that environmental factors, personality, and genetics all contribute.”
The genetic variants identified explain only a portion of the variation in sexlessness, with genetics accounting for roughly 15 percent of the difference between individuals.
The remaining 85 percent is shaped by environment, social experience, personal choice, and factors not yet fully understood.
The researchers also stressed that polygenic scores based on their findings cannot predict whether any individual will be sexless.
The effects of each individual genetic variant are extremely small.
It is only in aggregate, across thousands of variants, that the statistical signal becomes visible.
There is also an important evolutionary footnote embedded in the data.
When the team examined ancient DNA samples from European populations spanning the last 12,000 years, they found that one of the genetic variants associated with sexlessness had steadily declined in frequency over that period, exactly what you would expect if natural selection had been quietly working against it across thousands of years of human history.
That finding suggests the genetic predispositions the study identified are not new.
They have been present throughout human history, gradually reduced by selection pressure, but never eliminated entirely.
What This Means Beyond the Data
It is important to note, as the researchers themselves emphasised, that sexlessness is not always involuntary.
Approximately one percent of the population identifies as asexual, meaning they experience little or no sexual attraction, and many people make deliberate, fulfilled choices to live without sexual relationships.
The study found that religious individuals were significantly more likely to have never had sex in their lifetime, particularly women, underscoring that personal values and belief systems remain powerful shapers of intimate behavior independent of genetic predisposition.
What the study captures, then, is a spectrum.
At one end are people for whom sexlessness is a genuine and comfortable choice.
At the other are people for whom it is an unwanted outcome shaped by a constellation of traits, experiences, and circumstances that science is only now beginning to map with any precision.
Co-researcher Brendan Zietsch of the University of Queensland summed it up in the Amsterdam UMC release: “We see a pattern of people who are more socially withdrawn and therefore have more difficulty finding a partner.”
That is not a moral judgment.
It is a description of how biology, personality, social environment, and economic circumstance weave together to shape one of the most intimate dimensions of a human life.
The study does not explain everything, and its authors say plainly that much further research is needed before the causal pathways can be properly untangled.
But it represents the most serious, large-scale attempt yet to answer a question that has been hiding in plain sight: why, for some people, this most fundamental of human experiences never arrives.
And the answer, it turns out, is written in places as varied as a person’s DNA, their childhood social experiences, the city they live in, and the economic conditions of the neighbourhood around them.
The Broader Social Crisis Behind the Numbers
The findings of this study do not exist in isolation.
They land in the middle of a growing conversation about what researchers are calling a global loneliness epidemic, one in which sexlessness is both a symptom and a contributing factor.
A landmark 2025 report from the World Health Organization’s Commission on Social Connection found that social isolation and loneliness are now widespread across all age groups, with serious and under-recognised consequences for both physical and mental health.
The WHO report described the situation as a public health crisis requiring urgent coordinated action, comparable in seriousness to better-known threats like obesity and smoking.
The sexlessness study feeds directly into that concern.
Sexless individuals, the data showed, were significantly more likely to lack a close confidant, to visit friends and family less frequently, and to feel that their life lacked meaning.
These are not trivial inconveniences.
Research published in World Psychiatry has documented that social disconnection is an independent predictor of mortality, with effects on lifespan comparable to smoking 15 cigarettes a day.
Sexlessness, for many of the people experiencing it, is not just an absence of physical intimacy.
It is a marker of a much deeper kind of isolation, one that compounds across years and decades into measurable harm.
The Incel Problem: When Isolation Turns Dangerous
The researchers were careful not to sensationalise their findings, but they did acknowledge one of the more troubling social dimensions of involuntary sexlessness directly in their paper.
A subset of men who experience chronic romantic and sexual rejection have coalesced online into communities known as “incels,” short for involuntary celibates.
As researchers writing in Harvard Medical School’s Trends in Medicine have argued, incel communities are associated with serious mental health deterioration, misogynistic ideology, and in a small number of cases, radicalisation and violence.
The geographic findings of the sexlessness study are particularly relevant here.
Earlier research had found that incel-related social media activity was more likely to originate from regions with fewer women relative to men and higher income inequality, precisely the same conditions this new study independently identified as drivers of male sexlessness.
That convergence matters.
It suggests that the conditions producing involuntary sexlessness and the conditions producing radicalisation in response to it are rooted in the same structural inequalities, not simply in the psychology of individuals.
Addressing those inequalities, rather than pathologising the people caught in them, may be a more productive social response than the one currently on offer.
What Society Gets Wrong About Sexless People
Perhaps the most important contribution of this research is not any single finding but the overall shift in framing it demands.
For most of recent history, people who had never had sex were either invisible in public conversation or reduced to cultural caricature.
They were assumed to have made a deliberate choice, or to be socially deficient in some obvious and correctable way, or to belong to a niche religious or ideological category.
What this study reveals is that the reality is far more complex and far more human.
The people captured in this data are, on average, intelligent, educated, conscientious, sober, and deeply lonely.
Many of them likely never set out to live without an intimate connection.
They arrived there through a combination of genetic predispositions, formative social experiences, economic circumstances, and the particular architecture of the social environments they inhabited.
As co-author Brendan Zietsch wrote in The Conversation, the study points toward people who are “more socially withdrawn and therefore have more difficulty finding a partner,” and understanding that pattern is the first step toward removing barriers rather than assigning blame.
That reframe matters not just for scientific accuracy but for compassion.
It matters how schools support socially isolated adolescents before their trajectories are set.
It matters how therapists and healthcare providers respond to the specific kind of loneliness that goes unaddressed because it carries social stigma.
And it matters for how societies design the economic and physical environments in which people meet, connect, and build lives together.
The science here is still young.
The causal pathways are still being untangled, the genetic mechanisms are still poorly understood, and the full range of human experience captured by the word “sexlessness” remains far more diverse than any single dataset can fully represent.
But the direction is clear: this is not a personal failing.
It is a human condition shaped by forces larger than any individual, and it deserves the same serious scientific and social attention we give to any other significant dimension of health and well-being.
Sources: Proceedings of the National Academy of Sciences, Abdellaoui et al. 2025 | Amsterdam University Medical Center | Technology Networks | Psychiatric Times | PubMed | Psychology Today | Harvard Medical School, Trends in Medicine
