Changes in Penile-Vaginal Intercourse Frequency and Sexual Repertoire from 2009 to 2018: Findings from the National Survey of Sexual Health and Behavior

Changes in Penile-Vaginal Intercourse Frequency and Sexual Repertoire from 2009 to 2018: Findings from the National Survey of Sexual Health and Behavior. Debby Herbenick, Molly Rosenberg, Lilian Golzarri-Arroyo, J. Dennis Fortenberry & Tsung-chieh Fu. Archives of Sexual Behavior, Nov 19 2021. https://link.springer.com/article/10.1007/s10508-021-02125-2

Abstract: Solo and partnered sexual behaviors are relevant to health, well-being, and relationships. Recent research shows that sexual frequency has declined in the U.S. and in other countries; however, measurement has been imprecise. We used data from 14- to 49-year-old participants in the 2009 and 2018 waves of the National Survey of Sexual Health and Behavior (NSSHB), a confidential U.S. nationally representative survey that is conducted online. We aimed to: (1) assess changes in frequency of past-year penile-vaginal intercourse and (2) examine combinations of past-year sexual behaviors for each of the two waves. We hypothesized that we would observe lower frequency of penile-vaginal intercourse (PVI) from 2009 to 2018 and that we would observe greater engagement in sexual repertoires involving non-coital partnered behaviors (e.g., partnered masturbation, oral sex) in 2018 as compared to 2009. Participants were 4155 individuals from the 2009 NSSHB (Adolescents: 406 females, 414 males; Adults: 1591 women, 1744 men) and 4547 individuals from the 2018 NSSHB (Adolescents: 416 females, 411 males; Adults: 2007 women, 1713 men). Compared to adult participants in the 2009 NSSHB, adults in the 2018 NSSHB were significantly more likely to report no PVI in the prior year (28% in 2018 vs. 24% in 2009). A similar difference in proportions reporting no PVI in the prior year was observed among 14–17-year-old adolescents (89% in 2018 vs. 79% in 2009). Additionally, for both adolescents and adults, we observed decreases in all modes of partnered sex queried and, for adolescents, decreases in solo masturbation.

Discussion

The present study used data from two waves of US nationally representative survey data to examine changes in sexual frequency and sexual repertoire between 2009 and 2018. Our research adds to the literature by using detailed measures of sexual behaviors beyond oral, vaginal, and anal intercourse; we did this in order to examine whether an explanation for declines in coital frequency might be explained by increases in non-coital behaviors. However, in addition to finding decreased PVI frequency in 2018 as compared to 2009, we found significant decreases across all partnered sexual behaviors assessed and, for adolescents, decreases in the proportion of adolescents reporting solo masturbation in the prior year as well. Overall, our findings are consistent with studies from multiple countries that have documented declines in sexual frequency. Because our sample was limited to individuals ages 14–49, we were unable to examine sexual behavior trends among people aged 50 and older. However, our findings align with studies that have found greater proportions of young people reporting no partnered sexual behaviors in the prior year (e.g., Burghardt et al., 2020; Ghaznavi et al., 2019; Ueda & Mercer, 2019; Ueda et al., 2020).

Other than Natsal and ASHR, most population-representative studies examining sexual frequency trends have not included those under age 18 and thus less has been known at the population level about sexual trends among younger adolescents. Our study extends the literature by including adolescents as young as 14 years old in our analytic sample (the youngest participants in Natsal and ASHR were 16 years old). Findings from our research also align with the US Youth Risk Behavior Survey (YRBS) which has demonstrated declining rates of high school students reporting having ever had sex over a similar period of time (e.g., 46% in 2009 vs. 38% in 2019) (Centers for Disease Control & Prevention, 2020a). The lower rates of adolescents’ reports of solo masturbation and PVI in 2018 are striking and deserve further study. These differences aren’t trivial: for example, the proportion of adolescents reporting neither solo nor partnered sexual behaviors (Latent Class 2) increased from 28.8% of young men and 49.5% of young women in 2009 to 43.3% of young men and 74.0% of young women in 2018.

A number of potentially convergent social and cultural changes may contribute to these substantial shifts in young people’s sexual behaviors. Widespread internet connectivity and emerging new technologies have added a new medium for providing sexual experiences outside of physical sex with a partner (e.g., sexting, easy access to sexually explicit media) (Doring et al., 2017; Twenge et al., 2017; Wright, 2013; Wright et al., 2013). Alcohol use has decreased among adolescents (Miech et al., 2019), and many young people have been engaged in conversations about sexual consent (such as through the #MeToo movement led by Tarana Burke, the Obama/Biden administration’s It’s On Us campaign, and recent high profile rape cases) (e.g., Armstrong & Mahone, 2017; PettyJohn et al., 2019). Also, more contemporary young people identify with non-heterosexual identities—including asexual identities—and more young people identify in gender expansive ways (Newport, 2018; Watson et al., 2020). It is also possible that secular trends reflect a tendency to have over-reported sexual behavior in earlier years, with more accurate reporting now as people become more comfortable with online presentations of themselves. These are among the many potential influences on adolescent sexual development and expression; subsequent research might examine how each of these may be contributing to changing patterns of sexual frequency and repertoire at the population level. Greater investment in understanding adolescent sexual development beyond risk is warranted, including how adolescents form, sustain, and interpret intimate relationships.

In terms of young adults, some research suggests that increasing use of computer games and social media may be implicated in young adults’ declining sexual activity (Lei & South, 2021). A recent analysis of 18–23-year-olds in 2007–2017 waves of the Transition to Adulthood Supplement of the Panel Study of Income Dynamics found that increased use of computer games, decreased alcohol use, decreased earnings, and declines in romantic relationship formation explained 76% of the decline in sexually active young adults in their sample (Lei & South, 2021). The median age at first marriage in the USA has also increased (US Census, 2020). It is worth noting that many published reports of adult sexual behavior (including ours) begin by describing the potential positive contributions of sex to health and quality of life. Media coverage of declining sexual activity tends to be similarly imbued with a sense that—in spite of risks that include unintended or mistimed pregnancy, sexually transmitted infections, and/or sad or lonely feelings connected to sex—partnered sex is generally pleasurable, joyful, connecting, and/or beneficial and thus declines in partnered sex among adults may be concerning (e.g., Feder, 2020; Julian, 2018). The age-old question on how much sex is too much and how little sex is not enough comes to mind. Given the impacts of the COVID-19 pandemic on physical and mental health, sexual behavior, relationships, and (for youth) in-person school and extracurricular activities, ongoing population-level research on sexual development and behaviors will be important (Finnerty et al., 2021; Rosenberg et al., 2021).

Positive aspects of adolescent partnered sex are less often highlighted. For example, in the section of the 2019 YRBS report that shows sexual behavior trends over time, the row that shows declining percentages of high school students who have “ever had sex” also features a green symbol (similar to the US traffic light system) which the legend describes as moving “in right direction” (Centers for Disease Control & Prevention, 2020b). The line between adolescence and adulthood has always been tenuous—perhaps particularly so when it comes to sexual behavior—but we must continue to interrogate how declining adolescent sexual activity is in the “right direction” yet declining adult sexual activity warrants concern. Solo and partnered adolescent sexual exploration are developmentally normative, offer opportunities for learning and joy, and are supportive of adult sexual development (Hensel et al., 2011; Robbins et al., 2011; Tolman & McClelland, 2011). Our findings have implications for those in policy roles, who might consider other helpful metrics of understanding changes in adolescent sexual experience—as an example, tracking the proportion of adolescent sex that is wanted, consensual, and even pleasurable may be illuminating.

Findings from our study also extend the existing literature by including solo masturbation among participants’ sexual behaviors. For both adults and adolescents, we found a latent class that was marked by engaging in solo masturbation. This highlights the important role of masturbation in people’s sexual expression; however, we note that the proportion of adolescents in the solitary masturbation Latent Class 1 decreased in 2018 compared to 2009, while the proportion reporting neither solo nor partnered sex increased. The 2009/2019 NSSHB waves did not ask participants how they feel about their sexual lives or whether they would like to have more sex or less sex than they are having; however, we note that Ueda and Mercer (2019) found that most Natsal participants who reported no prior year partnered sex but who did have prior partnered sexual experience were not dissatisfied with their sexual lives. Subsequent research should include more questions about people’s own subjective assessments of their sexual lives and feelings about their solo and partnered sexual behaviors.

Similarly, we need to understand more about how people’s subjective feelings about the sex they’ve experienced may shape their subsequent choices about sex. At the population level, the 2009 NSSHB demonstrated that anal intercourse had nearly doubled in lifetime prevalence since the National Health and Social Life Survey of the early 1990s. However, anal sex remained infrequent overall in any given year (though much more frequent among gay and bisexual men) (Dodge et al., 2016; Herbenick et al., 2010a). Anal sex has generally been rated as unappealing among US adults (Herbenick et al., 2017), and several qualitative studies examining anal intercourse between women and men found that—although anal sex behaviors were pleasurable to some—anal sex was often marked by pressure, coercion, lack of communication, fear, and pain among women (e.g., Fahs & Gonzalez, 2014; Fahs et al., 2015; Herbenick et al., 2015, 2019a, 2019b; Jozkowski et al., 2014). Given these experiences, it is perhaps not surprising to have observed a decrease in anal intercourse between the 2009 and 2018 NSSHB, but that does not explain other decreases across all partnered sexual behaviors queried.

Recent research suggests that some sexual behaviors sometimes described as aggressive or as “rough sex” may have grown in prevalence in the USA, including choking during sex (which is technically a form of strangulation) (Herbenick et al., 2020; Herbenick et al., 2021a). Like anal sex behaviors, choking/strangulation is often wanted, asked for, and/or perceived as pleasurable (Herbenick et al., 2021a, 2021b). However, being choked/strangled has also been identified by many women as an example of something a partner has done during sex that made them feel scared (Herbenick et al., 2019a, 2019b), which is not surprising given that choking/strangulation is a common feature of sexual assault, intimate partner violence, and (in rare cases) is lethal even as part of consensual sex (e.g., Mcquown et al., 2016; Roma et al., 2013; Sendler, 2018). Subsequent research might examine the extent to which partnered sex may be declining, at least for some subset of the population, as a result of experiencing unpleasant or frightening experiences during otherwise consensual sex (e.g., being hit, punched, slapped, or choked without consent, or as a form of sexual compliance).

Strengths and Limitations

Our study was subject to several strengths and limitations. Among our strengths, we used data from the 2009 and 2018 waves of the NSSHB, a US nationally representative probability survey. The NSSHB is unique in that it includes items related to both sexual frequency and repertoire as well as a detailed assessment of solo and partnered sexual behaviors, which allowed for an examination of specific behavioral trends over two time periods. Other US national surveys, such as the GSS, YRBS, National Survey of Family Growth, and the National Longitudinal Study of Adolescent to Adult Health, are more limited in the scope of sexual behavior items assessed (Centers for Disease Control & Prevention, 2020a, 2020b; Harris et al., 2009; NORC at the University of Chicago, 2016). Both the 2009 and 2018 NSSHB waves were conducted through online, confidential surveys which has been shown to facilitate the reporting of sensitive behaviors. Among our limitations is that—in terms of frequency of sex—we were limited to comparisons of PVI (i.e., frequency of other sexual behaviors had not been assessed in both waves). Also, neither wave included an oversample of individuals who identify as lesbian, gay, bisexual, or asexual and thus—being a general population survey—findings largely reflect majority groups (e.g., heterosexual identified people). This becomes particularly apparent in examining the LCA classes, for which PVI loaded heavily on three of the four adult classes and two of the four adolescent classes. This is likely a fair representation of sex between males and females, given prior research showing the prevalence of PVI in many combinations of sex between women and men, and other research describing the intercourse imperative (Herbenick et al., 2010b; Richters et al., 2006). However, it does mean that these LCA classes do not reflect the rich diversity of all US adolescents and adults. Subsequent research might investigate similar constellations of intimate and/or sexual behaviors among dedicated samples of LGBTQ + individuals and/or among general population samples with sufficiently sized oversamples of LGBTQ + individuals.

Similarly, although the 2009/2018 NSSHB waves included a broad range of sexual behaviors for comparison, we would have liked to have been able to compare additional behaviors across waves but did not have additional items common among the two waves (e.g., kissing, cuddling, sex toy use, sexting, reading erotica, and/or watching pornography). As the NSSHB is focused on sexuality, we also did not have measures of more general behaviors (e.g., media use, substance use, mental health, physical health, perceived racism, political stress, etc.) that could have shed light on potential changes in sexual behaviors from 2009 to 2018. Finally, although our findings may help clinicians contextualize questions or concerns their clients have about how often people have sex, it is left to the client–clinician relationship, and to people themselves, to examine contexts of pleasure and satisfaction.