Enshrined in the Ten Commandments, the adultery taboo has persisted throughout human history. According to the past 30 years of the General Social Survey (GSS), three out of every four American adults aver that extramarital sex is always wrong. At the other end of the spectrum, under three percent of the population thinks extramarital sex isn’t wrong at all. The number of Americans who report actually having sex outside the bonds of matrimony has held relatively steady, at around 16 percent. Annual fluctuations have been minor, rarely exceeding more than a percentage point in either direction. At first glace, it seems like America has made up its mind about extramarital sex.
But the broader trend has obscured startling changes: since 2000, older Americans are cheating more, while younger Americans are cheating less. These numbers are derived from GSS responses to this survey item: “Have you ever had sex with someone other than your husband or wife while you were married?” Survey respondents have been asked this question in each survey wave since 1991.
The growing age gap in extramarital sex is depicted in Figure 1, below. For the first few years of the millennium, there were scant age differences. Starting after 2004, Americans over 55 began reporting rates of extramarital sex that were about five or six percentage points higher than were being offered by younger adults. By 2016, 20% of older respondents indicated that their marriages were nominally adulterous, compared to 14% for people under 55. Most married Americans remain committed to monogamy, but the mounting age difference is noteworthy and statistically significant. Additional analysis suggests that the age difference cannot be explained by fundamental sociodemographic differences between respondents, including sex, age, race/ethnicity, or education.