Can you spot a cheater? Likely not…

Lucia F. O'Sullivan, Ph.D.

We were wondering if there was a good way to test who might be cheaters when it comes to romantic relationship.  That is, are there personality traits that are useful for characterizing who is versus who is not a cheater?  There are studies of personality traits and infidelity before this one, but most have not examined more than 2-3 traits at a time.  Infidelity in this case refers to “the violation of a couple’s assumed or stated agreement concerning romantic and/or sexual exclusivity.” This question is interesting in light of the fact that rates of infidelity (recent and lifetime) are really quite high even though most adults (94-99% in any survey) expect monogamy in both their romantic and sexual relationships (Treas & Giesen, 2000).  Rates range from 23% to 63% (depending on how you ask the question and which behaviours you focus upon) among men and 19% to 45% among women. If rates are so high—can there really be a personality trait, or traits, that capture that many people?

We were also struck by reports from other work that many cases of infidelity actually came out of the blue—or at least, weren’t anticipated, planned, expected by the person engaging in the infidelity. The partner was usually someone that the person saw quite frequently, spent a lot of time with (such as a work colleague), or had a close bond with in some other context.  This suggested to us that circumstances or context might be more important than personality.

With Kirstie Gibson, Lucia O’Sullivan surveyed 474 young adults about their close intimate relationships.  When asking questions about infidelity, it is of course very important to ensure that participants know their responses are completely anonymous and can never be tracked back to them by the researchers or others. Online surveys are really a superior way of ensuring that is the case.  We surveyed participants about their current relationship, infidelity history in their current relationship, and had them complete an array of personality measures.

It was important to establish first that they had an agreement or expectation with their intimate partner that they would be romantically/sexually exclusive.  Only three people did not have such an understanding so we excluded them from our analyses. Almost all others expected romantic (96%) or sexual (94%) exclusivity from a partner “always” or “absolutely always.” Despite the expectation of exclusivity, 9% reported having engaged in romantic infidelity and 13% reported sexual infidelity in their current relationship (the average duration of the relationship was just under 3 years). These are fairly typical rates of infidelity. There were no gender differences in rates.

Most interesting to us, however, was that personality was a really poor predictor of infidelity. (There was a slight effect for extraversion, but that was it). Better predictors was knowing whether the participant had felt any attraction to someone other than their partner (e.g., co-worker, fellow student) and whether the quality of their relationship was less than ideal (not necessarily poor, but not great). These might be viewed as “vulnerability factors” in a sense given that most people report not wanting to violate the exclusivity of their relationships—even if they do. 

Take home message:  If your relationship isn’t doing so well and/or you are getting distracted by someone other than your partner—these might be risk factors for engaging in infidelity.  Another study from our research program (with Charlene Belu) explores infidelity in points of transition to new relationships. Many people start a new relationship (or are “poached” from their old one) before they have fully ended one that just isn’t working…  More about that shortly.