Sex Differences in Self-reported Infidelity and its Correlates

We examined sex differences in the prevalence, incidence, reasons for, and consequences of infidelity. Participants (Study 1, 543 undergraduates in the Northwestern US; Study 2, 313 undergraduates and 233 community members in the Mid-Atlantic US), reported on infidelity by questionnaire. Using a broad definition of cheating, women reported being as unfaithful or more unfaithful than men. Men were more suspicious about cheating and more likely to discover the cheating than women. Women were more likely to break up with their partners, to begin new relationships after cheating, and to report reasons for cheating that may indicate a desire to switch long-term mates, such as being unhappy in the current relationship. Results are discussed in the context of evolutionary theory.