Once a Cheater, Always a Cheater? Serial Infidelity Across Subsequent Relationships.

Although there is a large body of research addressing predictors of relationship infidelity, no study to our knowledge has specifically addressed infidelity in a previous relationship as a risk factor for infidelity in a subsequent relationship. The current study addressed risk for serial infidelity by following adult participants (N = 484) longitudinally through two mixed-gender romantic relationships. Participants reported their own extra-dyadic sexual involvement (ESI) (i.e., having sexual relations with someone other than their partner) as well as both known and suspected ESI on the part of their partners in each romantic relationship. Findings from logistic regressions showed that those who reported engaging in ESI in the first relationship were three times more likely to report engaging in ESI in their next relationship compared to those who did not report engaging in ESI in the first relationship. Similarly, compared to those who reported that their first-relationship partners did not engage in ESI, those who knew that their partners in the first relationships had engaged in ESI were twice as likely to report the same behavior from their next relationship partners. Those who suspected their first-relationship partners of ESI were four times more likely to report suspicion of partner ESI again in their next relationships. These findings controlled for demographic risk factors for infidelity and held regardless of respondent gender or marital status. Thus, prior infidelity emerged as an important risk factor for infidelity in next relationships. Implications for novel intervention targets for prevention of serial relationship infidelity are discussed.