Marital Infidelity: How Common Is It?

Marital infidelity is difficult to research because most people are reluctant to admit it. One survey made headlines showing that only a tiny percentage of spouses cheat. But the researchers interviewed respondents with their spouses present. Duh!

Even without spouses, results depend on how questions are asked. University of Colorado researchers surveyed 4,800 married women using face-to-face interviews and an anonymous questionnaire. In the interviews, only 1 percent said they'd cheated during the past year. But the anonymous questionnaire showed 6 percent.

Meanwhile, controversy clouds the definition of "infidelity." Most say it's sex with anyone who isn't your spouse. But what about spouses who are separated but not divorced? What about open marriages? And don't-ask-don't-tell marriages? Is infidelity any sex outside of marriage? Or secret sex? What about people in heterosexual marriages who have homosexual flings? Finally, does cheating require intercourse? What if you have only oral sex? Or handjobs? Or passionate kissing?

Arguably the best research on this subject is the General Social Survey (GSS) conducted annually since 1972 by University of Chicago researchers. For 37 years, they have asked a representative national sample about infidelity. The results have been consistent. Every year, 10 percent of spouses admit cheating--12 percent of men, 7 percent of women.

But in our culture, men with multiple partners are often envied as studs, while similar women are dismissed as sluts. As a result, we would expect men to admit infidelity more freely. In many non-Western cultures, anthropologists have found no gender differences in infidelity rates. Perhaps the same is true for us, but cultural assumptions color admissions.

Recently, the GSS has shown two notable changes--more cheating by spouses over 60 and under 35. These changes have been modest, so it's hard to know if they are real. But many social scientists contend they are, and have proposed explanations.

Among older folks, the reason most often cited is health. Sex tracks health. Today 60 is the new 40, which might explain the rise in cheating among older spouses. However, while many of today's 60-somethings are healthier than their counterparts a generation ago, today we have much more diabetes, a condition that often causes sexual impairment, and substantially more obesity, which may make people feel unattractive, and raises risk of arthritis, heart disease, and cancer, all of which reduce libido and sexual function. In addition, older adults take considerably more medications than they did a generation ago. Many drugs cause sex problems, notably, antidepressants and blood pressure medications. So, does better health in those over 60 explain the increases in infidelity? Maybe, maybe not.

Another oft-cited reason for horny elders is erection medication, which some say has encouraged older men to cheat. But two recent studies show that only 10 percent of men over 50 have even tried these drugs, let alone become regular users. With erection medications used by so few older men, how much of a difference could they make?

Maybe rising infidelity has to do with more working women, particularly women traveling on business, which provides opportunities to dally discreetly. But homemakers of yore had plenty of opportunities for extra-marital sex: the postman, milkman, repairmen, and delivery men of all stripes. Meanwhile, cheating is up only in women over 60 and under 35. If travel explains the increase, why hasn't it risen in women 35 to 59? Most of them work outside the home, and many travel on business.

The fact is, no one knows the true prevalence of marital infidelity and every explanation for supposedly rising rates is open to serious question. What do you think?