Why Are Fewer Young Adults Having Casual Sex? - Scott J. South, Lei Lei, 2021

The authors find no evidence that trends in young adults’ economic circumstances, internet use, or television watching explain the recent decline in casual sexual activity.The percentage of young adults who engage in sexual intercourse has been declining in recent years. We examine eight potential drivers of the decline in casual sexual behavior among young adults, reflecting trends in employment, earnings, financial debt load, coresidence with parents, use of electronic media, television watching, computer video gaming, and alcohol consumption.Our study builds on a recent analysis by Lei and South (2021) that examined reasons for the recent decline in sexual activity among young adults. These secular changes in the timing of the adoption of adult roles are accompanied by, and perhaps caused by, several critical changes in young adults’ lives that may have implications for their propensity to engage in casual sexual intercourse (Allison and Risman 2017).One change in young adults’ lives that might help explain the decline in casual sex is increasing financial uncertainty. Because there is some evidence that alcohol consumption increases young women’s more than young men’s odds of engaging in casual sex (Owen, Finchan, and Moore 2011), it is possible that the decline in alcohol consumption explains more of the decline in young women’s than in young men’s propensity to have sex outside of a committed romantic relationship.Data for this analysis come from the 2007 through 2017 waves of the PSID-TAS. We believe that these limitations to the measurement of casual sex are at least partially compensated for by the PSID-TAS’s rich measures of potential explanations for the decline in young adult sexual activity.The trend in the probability that the PSID-TAS respondents report having had casual sex is indicated by a continuous variable for the year the survey was taken (2007 = 7, 2009 = 9, 2013 = 13, 2015 = 15, 2017 = 17). Alcohol consumption is measured by a question asking respondents how often they drank alcohol in the past year, with response categories ranging from 1 (never) to 7 (every day).In addition to variables that might help explain the decline in the frequency of casual sex, the models also include several other potential predictors of the likelihood that unpartnered young adults have recently engaged in sexual intercourse. For both women and men, the average frequency of watching television falls between “several times a week” and “almost every day.” Among women, the mean frequency of drinking alcohol during the past year falls between “about once a month” and “several times a month,” while for men the mean falls slightly above “several times a month.”Table 2 begins to shed light on the ability of the hypothesized mediators to explain the trend in young adult casual sexual activity by presenting descriptive statistics for the focal variables for the study frame’s initial year (2007) and final year (2017). Both women and men drank alcohol significantly less often in 2017 than in 2007.Table 3 presents a series of logistic regression models of the odds that young women engaged in casual sex during the four weeks preceding each PSID-TAS interview. Consequently, even though young women’s frequency of computer gaming has increased over time (Table 2), this cannot explain their decline in casual sex. Moreover, controlling for frequency of drinking reduces the coefficient for survey year, which drops from –.065 in model 1 to –.051 in model 7.Model 8 includes as mediators those factors that, in prior models, explained at least some of the decline in young women’s propensity to have casual sex. The odds that young women who report drinking daily (scored 7) engage in casual sex are almost seven times the odds for young women who report never drinking (scored 1) (e[7 − 1][.320] = 6.8).The analysis presented in Table 4 hints at the factors that might explain the recent decline in casual sexual intercourse among young women. As anticipated by the results in Table 3, the trends in Internet use and television watching significantly suppress the decline in young women’s propensity to engage in casual sexual intercourse. Mediation Analysis of Factors Explaining the Decline in Casual Sex among Young Women: Panel Study of Income Dynamics Transition into Adulthood Supplement, 2007 to 2017.Table 4. Mediation Analysis of Factors Explaining the Decline in Casual Sex among Young Women: Panel Study of Income Dynamics Transition into Adulthood Supplement, 2007 to 2017.Tables 5 and 6 present a largely parallel analysis for young men. As shown in model 1 in Table 5, net of the effects of the control variables, the odds that young men engage in casual sex are estimated to have declined by about 7 percent per year ([1 – e–.073] × 100) between 2007 and 2017. Mediation Analysis of Factors Explaining the Decline in Casual Sex among Young Men: Panel Study of Income Dynamics Transition into Adulthood Supplement, 2007 to 2017.Table 6. Mediation Analysis of Factors Explaining the Decline in Casual Sex among Young Men: Panel Study of Income Dynamics Transition into Adulthood Supplement, 2007 to 2017.Although several of the hypothesized mediating factors are significantly associated with the odds that young men have casual sex (Table 5, models 2–7), only three of them appear to explain a nontrivial proportion of the decline in casual sexual activity. Considered together, the mediators that explain at least some portion of the decline (employment and earnings, parental coresidence, computer gaming, and drinking) explain 57 percent of the drop in young men’s casual sexual activity.We performed several additional analyses. Even in this case, however, proportion of the secular decline in the log odds of having casual sex attributable to the rise in parental coresidence, almost 20 percent, is reasonably large.Adolescents and young adults are increasingly less likely to have sexual intercourse outside of a romantic relationship, but the causes of this decline in casual sex have not been rigorously evaluated. Of the various sources of the decline in sexual activity considered in this analysis, the decline in alcohol consumption is the only factor that explains a significant portion of the decline in young women’s probability of engaging in casual sex.A somewhat different story emerges for young men. The factors hypothesized to explain the decline in casual sexual intercourse explain a greater portion of the decline in young men’s than in young women’s propensity to engage in casual sex.We find no evidence that some other transformations in the lives of emerging young adults can explain the decline in their casual sexual activity. And among young women the increase in the use of the Internet appears to actually suppress what would otherwise have been a larger drop in the propensity to engage in sex with someone who is not a romantic partner.We acknowledge that our findings raise questions as to what factors are driving changes in these proximate sources of the decline in young adult casual sexual activity. Trends in the hypothesized mediating factors included in this analysis explain more than half of the decline in young men’s odds of engaging in casual sex but account for only about one quarter of the decline in young women’s probability of having a nonromantic sexual encounter.