An old saying goes “once a cheater, always a cheater” — and new research from the University of Denver suggests that there may be a grain of truth to that statement.

Kayla Knopp and colleagues found that partners in romantic relationships were three times more likely to cheat on their next partner if they did so in their first relationship. The study was published in Archives of Sexual Behavior.

“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,” the researchers explained.

“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.”

Participants (N=1294) were recruited using a targeted-listed telephone sampling strategy. Data collection occurred through surveys by mail, spanning a total of eleven waves of data during a 5-year period.

The sample of the current study (N=484) that completed 10.0 of 11 survey waves included 329 women (68%) and 155 men. Participants in this sample reported at least two romantic relationships over the course of the study (total range = 1-7 relationships, M= 1.6, SD = 0.95).

The ethnic demographic included White 76%, Black or African American 15.3%, American Indian or Alaskan Native 0.8%, Asian 2.9%, Native Hawaiian or Pacific Islander 0.3%. Sample ages ranged from 18 to 35 years old (M=24.8, SD=4.73).

The researchers also found that those who suspected ESI of their partner in their first relationship were four times more likely to suspect ESI again in their next relationship. The researchers controlled for demographic risk factors for infidelity.

The researchers conclude: “Results from this study indicated that people who engaged in infidelity themselves, knew about a partner’s infidelity, or suspected a partner of infidelity had a higher risk of having those same infidelity experiences again in their next romantic relationships.”

“The current study provides novel contributions to established notions of infidelity across serial relationships, including that personal engagement in ESI and perceptions of partner engagement in ESI predict increased risk of serial infidelity in subsequent relationships.”

“Infidelity can harm individuals and relationships, and these results can inform prevention or intervention efforts by targeting risk factors based on previous relationship patterns in addition to the various individual, relational, and contextual factors demonstrated to predict infidelity in previous work.”

The study, “Once a Cheater, Always a Cheater? Serial Infidelity Across Subsequent Relationships”, was authored by Kayla Knopp, Shelby Scott, Lane Ritchie, Galena K. Rhoades, Howard J. Markman and Scott M. Stanley.