Thank you for a very interesting post on a fascinating topic. I want to take issue, however, with your conclusion that international trends in sexlessness yield a “completely different picture from the US”. I don’t think such a conclusion is warranted, at least as regards the three key variables you investigate: age at first sex, sexual frequency, and lifetime partner counts.
First, as regards age at first sex, a recent review of trends in age of sexual initiation in 33 European countries between 2010 and 2018 (de Graaf et al., 2024, https://www.tandfonline.com/doi/full/10.1080/00224499.2023.2297906) found that in virtually every country early sexual initiation (by the age of 15) had decreased (Table 1), suggesting that average age at first sex has likely been increasing over the last 10-15 years, in a reversal of the previous trend. The same trend was also documented earlier in two European countries: Scotland (Neville et al., 2017; https://academic.oup.com/eurpub/article/27/5/835/3603403; Table 2) and Portugal (Reis et al., 2019; https://karger.com/pjp/article/36/1/32/274974/Trends-in-Portuguese-Adolescents-Sexual-Behavior; Table 2). It may be therefore that many countries are now experiencing the same trend towards adolescent sexlessness as the USA, and that the only difference is one of timing, with the trend first starting in the USA in the mid/late-1990s (Finer & Philbin, 2014, https://pmc.ncbi.nlm.nih.gov/articles/PMC4011992/; Figures 1 and 2), then in certain European countries (and Japan, according to the study you cite) in the early 2000s, and then in other European countries over the following 15 years or so. (The findings you report for Australia from SSAHS suggest that Australian adolescents have bucked this trend, but as you say they may not be reliable, and so need to be confirmed by ASHR3).
Finally, as regards lifetime partner counts, as you show, they have increased in recent decades in all the countries you mention (France, the Scandinavian Countries, and the UK), particularly for women, but they have also increased in the USA (Twenge et al., 2015, https://www.researchgate.net/publication/275895690_Changes_in_American_Adults'_Sexual_Behavior_and_Attitudes_1972-2012; Tables 1 and 2). The “paradox” of increasing partner counts but lesser sexual activity is therefore present in the US findings as well as the international findings. However, while the trends may be real, the reported numbers are almost certainly not, given the very large and therefore almost certainly impossible gender disparities (Mitchell et al. 2018; https://www.tandfonline.com/doi/full/10.1080/00224499.2018.1481193), so it’s difficult to know what to make of the findings.
In conclusion, I think the international findings point in the same direction as the US findings, and suggest that there is a real global phenomenon of rising sexlessness, likely due to the same factors, though operating over slightly different time-periods.
'Finally, as regards lifetime partner counts, as you show, they have increased in recent decades in all the countries you mention (France, the Scandinavian Countries, and the UK), particularly for women, but they have also increased in the USA'
They had already begun to reverse after the 60s cohort in the study you linked. They've also been dropping among adolescents in the YRBS survey, and among young adult men in other datasets like Monitoring the Future -- for young women there's typically a flat trend, perhaps due to a countervailing trend in reporting bias.
In the UK natsal surveys, men's lifetime partners dropped slightly between the 2000 and 2010. So if by recent decades we mean the last two (the period most relevant to the sex recession), I don't think there's all that much of a paradox in these countries.
Yes, those are all good points. I only considered the overall age-aggregated findings from the descriptive statistics reported in Twenge et al. (2015; Table 2), and the corresponding findings from the French, Scandinavian and UK studies, which on the whole show increases in lifetime partner counts over the periods covered (though as you correctly note, the UK Natsal surveys show a small decline in male lifetime partner counts between the second, 2002, and third, 2012, surveys). But these findings don’t tell you much about changes predominantly affecting recent periods/cohorts, so you’re right to highlight more pertinent findings such as Twenge et al's (2015) model-based estimates (Figure 3), which suggest partner counts are declining in recent cohorts, in line with other changes in sexual behaviour.
>Women have seen the most dramatic changes since the sexual revolution, with substantial increases in lifetime partner counts
Average number of partners can't differ much by gender, because each new sex act increases count by same amount for each gender. It seems that women did grossly underreport number of sexual partners and degree of underreporting is smaller now.
Thank you for a very interesting post on a fascinating topic. I want to take issue, however, with your conclusion that international trends in sexlessness yield a “completely different picture from the US”. I don’t think such a conclusion is warranted, at least as regards the three key variables you investigate: age at first sex, sexual frequency, and lifetime partner counts.
First, as regards age at first sex, a recent review of trends in age of sexual initiation in 33 European countries between 2010 and 2018 (de Graaf et al., 2024, https://www.tandfonline.com/doi/full/10.1080/00224499.2023.2297906) found that in virtually every country early sexual initiation (by the age of 15) had decreased (Table 1), suggesting that average age at first sex has likely been increasing over the last 10-15 years, in a reversal of the previous trend. The same trend was also documented earlier in two European countries: Scotland (Neville et al., 2017; https://academic.oup.com/eurpub/article/27/5/835/3603403; Table 2) and Portugal (Reis et al., 2019; https://karger.com/pjp/article/36/1/32/274974/Trends-in-Portuguese-Adolescents-Sexual-Behavior; Table 2). It may be therefore that many countries are now experiencing the same trend towards adolescent sexlessness as the USA, and that the only difference is one of timing, with the trend first starting in the USA in the mid/late-1990s (Finer & Philbin, 2014, https://pmc.ncbi.nlm.nih.gov/articles/PMC4011992/; Figures 1 and 2), then in certain European countries (and Japan, according to the study you cite) in the early 2000s, and then in other European countries over the following 15 years or so. (The findings you report for Australia from SSAHS suggest that Australian adolescents have bucked this trend, but as you say they may not be reliable, and so need to be confirmed by ASHR3).
Second, as regards sexual frequency, as you note, it has declined since the 1990s or early 2000s in all five countries for which you cite study findings (Australia, France, Germany, UK, USA), and there are also similar findings from Finland (Kontula, 2015, https://www.researchgate.net/publication/304193379_Sex_Life_Challenges_The_Finnish_Case) and Japan (Wellings et al., 2019, https://www.bmj.com/content/bmj/365/bmj.l1525.full.pdf; reference 4). The finding you “didn’t expect” from France that declines have occurred in both married/cohabiting adults as well as singles is however also documented in the USA (Twenge et al., 2017, https://www.researchgate.net/publication/314273096_Declines_in_Sexual_Frequency_among_American_Adults_1989-2014; Figure 2), as well as the UK (Wellings et al., 2019; Figure 2 and Tables 1 and 2), and Finland (Kontula, 2015; pp. 688-689). (There appear to be no available findings for Australia, Germany, and Japan).
Finally, as regards lifetime partner counts, as you show, they have increased in recent decades in all the countries you mention (France, the Scandinavian Countries, and the UK), particularly for women, but they have also increased in the USA (Twenge et al., 2015, https://www.researchgate.net/publication/275895690_Changes_in_American_Adults'_Sexual_Behavior_and_Attitudes_1972-2012; Tables 1 and 2). The “paradox” of increasing partner counts but lesser sexual activity is therefore present in the US findings as well as the international findings. However, while the trends may be real, the reported numbers are almost certainly not, given the very large and therefore almost certainly impossible gender disparities (Mitchell et al. 2018; https://www.tandfonline.com/doi/full/10.1080/00224499.2018.1481193), so it’s difficult to know what to make of the findings.
In conclusion, I think the international findings point in the same direction as the US findings, and suggest that there is a real global phenomenon of rising sexlessness, likely due to the same factors, though operating over slightly different time-periods.
'Finally, as regards lifetime partner counts, as you show, they have increased in recent decades in all the countries you mention (France, the Scandinavian Countries, and the UK), particularly for women, but they have also increased in the USA'
They had already begun to reverse after the 60s cohort in the study you linked. They've also been dropping among adolescents in the YRBS survey, and among young adult men in other datasets like Monitoring the Future -- for young women there's typically a flat trend, perhaps due to a countervailing trend in reporting bias.
In the UK natsal surveys, men's lifetime partners dropped slightly between the 2000 and 2010. So if by recent decades we mean the last two (the period most relevant to the sex recession), I don't think there's all that much of a paradox in these countries.
Yes, those are all good points. I only considered the overall age-aggregated findings from the descriptive statistics reported in Twenge et al. (2015; Table 2), and the corresponding findings from the French, Scandinavian and UK studies, which on the whole show increases in lifetime partner counts over the periods covered (though as you correctly note, the UK Natsal surveys show a small decline in male lifetime partner counts between the second, 2002, and third, 2012, surveys). But these findings don’t tell you much about changes predominantly affecting recent periods/cohorts, so you’re right to highlight more pertinent findings such as Twenge et al's (2015) model-based estimates (Figure 3), which suggest partner counts are declining in recent cohorts, in line with other changes in sexual behaviour.
>Women have seen the most dramatic changes since the sexual revolution, with substantial increases in lifetime partner counts
Average number of partners can't differ much by gender, because each new sex act increases count by same amount for each gender. It seems that women did grossly underreport number of sexual partners and degree of underreporting is smaller now.