Introduction: Definitions of unfaithfulness and its consequences vary across different cultures, religions, and legal jurisdictions; however, having extramarital affairs is associated in most societies with a stigma. Therefore, the study of this sensitive topic is extremely complex, and its prevalence is often underestimated.
Aim: To offer a summary of available data in literature about unfaithfulness.
Method: An extensive Medline search was performed including the following words "unfaithfulness,""extramarital affairs,""infidelity,""men." The search, up to December 4, 2011, was restricted to English-language articles.
Main outcome measures: We reported literature data on the prevalence of unfaithfulness and on related psychobiological, sexual, and risk factors.
Results: Some surveys reported that 1.5-4% of married men had extramarital coitus in any given year, others that 23.2% of men have cheated during their current relationship. Different studies reported a lifetime prevalence of unfaithfulness between 15% and 50%. With respect to factors related to unfaithfulness, several authors reported that men with extramarital affairs more frequently have a dysfunctional primary relationship, in both relational and sexual terms. In addition, parenthood, as well as conflicts within the family, seem to be associated with a higher risk of having an affair. Furthermore, unfaithful men display a higher androgenization, larger testis volume, lower prevalence of hypoactive sexual desire, and better sexual functioning. Only few studies have evaluated the correlation between infidelity and cardiovascular risk, reporting that having an extramarital affair could have a negative impact on cardiac morbidity and mortality.
Conclusions: Several interpersonal, sexual, and biological factors are associated with having extramarital affairs. Unfaithfulness in men seems to be associated with a higher risk of major cardiovascular events.
© 2012 International Society for Sexual Medicine.