A reader submitted the following question: How have researchers operationalized infidelity in the past? What outcomes/predictors are associated with different "types" of infidelity?
Researchers have defined infidelity (known scientifically as “extradyadic behavior”) in many different ways. Some have defined it in very narrow terms (e.g., having sexual intercourse with someone other than your partner), while others have defined it much more broadly (e.g., having any type of physical or emotional intimacy outside of your relationship). To date, the vast majority of studies have focused on sexual (i.e., physical) cheating, with relatively fewer giving consideration to things like flirting, “sexting,” keeping secrets, and/or developing feelings for someone else (things that many people might feel are just as bad, if not worse, in some cases).
Given that scientists tend to ask about infidelity in such different ways, it is very difficult to gauge its true prevalence. For example, recent studies of cheating behavior have found that anywhere from 1.2% to 85.5% of respondents report having cheated at some point!1 If you’re concerned about that 85.5% figure, it may or may not comfort you to know that it refers to the percentage of participants in a college student sample who admitted to ever flirting with someone else while they were in a relationship.2
With that said, let’s address the second part of your question: what are the predictors and consequences of infidelity? Before I get to the answer, let me clarify that there really is no need to break this down by “type” of infidelity because regardless of whether we’re talking about sex or sexting outside of a relationship (or any other type of infidelity), the reasons people have for cheating and the outcomes of those actions tend to be pretty similar.
As far as reasons go, some of the most frequently reported include attraction to someone else, unhappiness or boredom in the current relationship, and simply having an opportunity arise.3 Of course, some people cheat for slightly more self-destructive reasons, such as wanting to retaliate against one’s partner and/or wanting to end a relationship but, fortunately, those tend to be less common motivations.
With respect to outcomes, no matter what form it takes, cheating tends to be bad for relationships. Not only is it frequently associated with breakup and divorce,3 but it is also linked to mental health problems including major depression and anxiety,4 as well as occasional incidents of domestic violence and, sadly, even murder.5 One final note about cheating is that even just the suspicion that one’s partner is cheating can be enough to devastate a relationship; no actual infidelity needs to occur. It is for this reason that I repeat my prior suggestion that you and your partner discuss your “cheating thresholds” up front in an attempt to avoid future misunderstanding and resentment (for more on this idea, see here).
1Luo, A., Cartun, M. A., & Snider, A. G. (2010). Assessing extradyadic behavior: A review, a new measure, and two new models. Personality and Individual Differences, 49, 155-163.
2Yarab, P. E., Sensibaugh, C. C., & Allgeier, E. R. (1998). More than just sex: Gender differences in the incidence of self-defined unfaithful behavior in heterosexual dating relationships. Journal of Psychology and Human Sexuality, 10, 45–57.
3Brand, R. J., Markey, C. M., Mills, A., & Hodges, S. D. (2007). Sex differences in self-reported infidelity and its correlates. Sex Roles, 57, 101-109.
4Cano, A., & Leary, D. (2000). Infidelity and separations precipitate major depressive episodes and symptoms of nonspecific depression and anxiety. Journal of Consulting and Clinical Psychology, 68, 774-781.
5Wilson M. I., & Daly M. (1996). Male sexual proprietariness and violence against wives. Current Directions in Psychological Science 5, 2–7.
Dr. Justin Lehmiller - Science of Relationships articles | Website/CV
Dr. Lehmiller's research program focuses on how secrecy and stigmatization impact relationship quality and physical and psychological health. He also conducts research on commitment, sexuality, and safer-sex practices.
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