Authorities agree that infidelity is the nation’s leading cause of relationship misery—and divorce. But beyond that, controversy abounds.
Consider the definition. If partners expect monogamy, sexual intercourse with anyone else is clearly infidelity. But what about genital play short of intercourse? Or breast play? Or passionate kissing? Or flirting? What about emotional intimacy with a non-spouse that never becomes sexual? Or sexting? Or watching porn? Or visiting sites that promote affairs? Some people consider all of the above cheating, while others parse distinctions.
Estimates of lifetime risk of infidelity vary considerably. Depending on the study, 20 to 52 percent of spouses admit they’ve cheated. The true prevalence is undoubtedly higher. Infidelity is stigmatized. People are reluctant to admit it.
Meanwhile, infidelity has long fascinated social science researchers. Psychologists, sociologists, and sexologists have published hundreds of studies in an ongoing effort to understand why spouses cheat, and how to undo the relationship damage it causes. They have also identified dozens of supposed risk factors that purportedly increase the likelihood of infidelity, including gender, age, education, health, religion, libido, anxiety, depression, sexual preference, self-esteem, relationship duration, relationship satisfaction, sexual attitudes, sexual satisfaction, and relationship status (dating, cohabiting, married). Findings have often been contradictory. Some studies show that as education increases, so does the likelihood of infidelity. Others show the opposite. And some show no correlation at all.
Unfortunately, most of the studies have considered only a few possible contributors. The reason: As the number of variables increases, statistical analysis becomes increasingly difficult. Recently, a team of researchers from the US, the UK, and Switzerland used the most current—and powerful—statistical tools to simultaneously analyze how 95 possible risk factors contribute to infidelity. The investigators were able to tease out what they call the most important. Their conclusion: Spouses’ demographics and beliefs are considerably less important than a few relationship and sexual issues.
Two Studies Involving 1,295 People
The researchers combined data from two studies. One involved a reasonably representative US sample of 891 adults in ongoing relationships—all genders and sexual preferences, average age 33, most with some college, and most married or cohabiting for an average of 6 years. Surveyed individually and anonymously, 32 percent admitted in-person infidelity—42 percent of the men, 26 percent of the women. Somewhat fewer (27 percent) admitted online infidelity (sexual emails, sexting, self-sexing for another on FaceTime or Zoom)—47 percent of the men, 19 percent of the women.
The other study included 202 couples (404 individuals) average age 33, also surveyed individually and anonymously—89 percent from the US, 11 percent from Canada, with demographics reasonably similar to those above, involved in their relationships for an average of 9 years. Seventeen percent admitted in-person dalliance—19 percent of the men, 16 percent of the women. Fourteen percent admitted online infidelity—17 percent of the men, 11 percent of the women.
Note how the two studies’ findings differ. In the second, the rate of infidelity was only around half of the first. But the researchers’ statistical tools allowed them to amalgamate both sets of findings and analyze them jointly.
The Top Predictors of In-Person Infidelity
The conventional wisdom says gender is key, that men are much more likely than women to be unfaithful. Indeed, that was the case in this report’s two samples. The men cheated more both in-person and online. Gender matters. But the researchers note that over the past several decades, the infidelity gender gap has narrowed as women’s opportunities for cheating have expanded—thanks to greater education, more work choices, and more opportunities to travel. Today the researchers argue, gender is no longer a major infidelity predictor.
The investigators found four major predictors of infidelity. In order of importance:
- Relationship dissatisfaction, Chronic relationship unhappiness substantially increases risk. It’s the single biggest contributor to in-person infidelity. (However, the reverse is not always the case. Infidelity doesn’t automatically mean that something is seriously wrong with the relationship. Plenty of people in good relationships step out.)
- Desire differences, “You’re insatiable!” “You never want to!” When desire differences become chronic and toxic, the more libidinous partner may well seek sex elsewhere.
- Less regard for each other. You may get along. But if couples feel bored with each other, if they feel less inclined to converse, spend time together, and help one another, that loss of caring substantially increases risk.
- sexual satisfaction, Some people become resigned to blah sex, to sex much less frequently than they would like, or to sex that’s less adventurous than they want. Others have affairs.
By itself, each of the above did not predict all that much infidelity. But as a group, they added up to be the most important risk factors.
The Top Predictors of Online Infidelity
As mentioned, beyond genital play with non-spouses, infidelity can be difficult to define. Online infidelity is even more so. For example, some women consider pornography detestable and believe that coupled men who view it are being unfaithful. But if that’s the case, then virtually every coupled, Internet-connected man on Earth cheats. This analysis is defined online infidelity more narrowly, as technological connections that facilitate intimacy with non-spouses—emailing, sexting, and mutual self-sexing by phone or on FaceTime or Zoom.
Like in-person infidelity, the online variety had less to do with demographics than with relationship and sexual issues. The top predictors were the same as for in-person infidelity, but their order of importance was a little different:
- Desire differences.
- Sexual satisfaction.
- Less regard for each other.
- Relationship dissatisfaction.
The researchers note that there’s no sure way to prevent infidelity. But to avoid it, they say the best approach involves couples closely monitoring their relationships and sexual satisfaction. If either deteriorates to the point that one or both partners think the couple has a problem, that signals real risk—and a need for relationship or sex therapy. No guarantees, of course, but if you get help before things go too far south, you just might avoid infidelity.