2025-09-18 カロリンスカ研究所(KI)
<関連情報>
- https://news.ki.se/when-sex-never-happens-new-research-maps-adults-without-sexual-experience
- https://www.pnas.org/doi/10.1073/pnas.2418257122
性のない生活:大規模研究が示す無性生活の身体的・認知的特性、性格特性、社会生態学的要因、DNAとの関連性 Life without sex: Large-scale study links sexlessness to physical, cognitive, and personality traits, socioecological factors, and DNA
Abdel Abdellaoui, Laura W. Wesseldijk, Scott D. Gordon, +7 , and Karin J. H. Verweij
Proceedings of the National Academy of Sciences Published:September 16, 2025
DOI:https://doi.org/10.1073/pnas.2418257122
Significance
Sexual partnerships can have a profound impact on societal well-being and evolution. Their absence can be detrimental to mental health and can lead to behavioral problems. Importantly, lifetime sexlessness offers an insightful measure for evolutionary fitness, as the absence of intimate partners would be most detrimental to reproductive success. Using large and well-characterized datasets, our research uncovers associations between this lesser-explored aspect of human behavior and a complex spectrum of physical, cognitive, and socioecological factors, partly connected by genetic predispositions. Lifelong sexless individuals are, on average, higher educated, use less substances, and feel lonelier and unhappier. Sexless men tend to live in regions with fewer women, and sexlessness was more prevalent in regions with higher income inequality.
Abstract
Romantic (typically sexual) relationships are important to personal, physical, mental, social, and economic well-being, and to human evolution. Yet little is known about factors contributing to long-term lack of intimate relationships. We investigated phenotypic and genetic correlates of never having had sex in ~400,000 UK residents aged 39 to 73 and ~13,500 Australian residents aged 18 to 89. The strongest associations revealed that sexless individuals were more educated, less likely to use alcohol and smoke, more nervous, lonelier, and unhappier. Sexlessness was more strongly associated with physical characteristics (e.g., upper body strength) in men than in women. Sexless men tended to live in regions with fewer women, and sexlessness was more prevalent in regions with more income inequality. Common genetic variants explained 17% (SE = 4%) and 14% (SE = 3%) of variation in sexlessness in men and women, with a genetic correlation between sexes of 0.56 (SE = 0.17). Polygenic scores predicted a range of related outcomes in the Australian dataset. Our findings uncover multifaceted correlates of human intimacy and raise important lines of enquiry in the evolutionary and social sciences.
