Infidelity

Lore & Background

Infidelity has been studied extensively since the Kinsey Reports in the early 1950s, which found that around half of men and a quarter of women studied had committed adultery. The Janus Report later reported that one-third of married men and a quarter of women have had an extramarital affair. Research has found that rates of infidelity among women increase with age, while men's likelihood decreases until the eighteenth year of marriage, then increases. One study found that men are more likely to engage in infidelity while their partner is pregnant, with an estimated 1 in 10 fathers-to-be doing so. Paternal discrepancy, a measure of infidelity, is generally 1–2% among European samples and less than 10% among sampled African populations. Gender differences in infidelity are commonly reported, with men generally showing higher rates. However, recent research suggests that factors such as power, sensation seeking, and financial independence may explain these differences. When tendency to sensation seek was controlled for, no gender differences in likelihood of being unfaithful were found.

Reader's Guide

Infidelity is a significant topic in sociology, psychology, and evolutionary psychology because it touches on fundamental aspects of human relationships, trust, and reproduction. The source article highlights that infidelity can cause severe psychological damage, including post-traumatic stress disorder, and that social consequences depend on gender. The data from the General Social Survey provides a long-term, consistent measure of infidelity rates, showing that approximately 12% of men and 7% of women admit to extramarital relationships. However, rates vary widely by study and methodology, with some finding up to 28% of men and 15% of women. The article also notes a debate in evolutionary psychology about whether an innate sex difference exists in jealousy responses to infidelity, with some studies using forced-choice questionnaires finding differences, while others using different methods do not. This ongoing debate underscores the complexity of infidelity as a human behavior, influenced by evolutionary pressures, social expectations, power dynamics, and individual personality traits. The article's discussion of paternal discrepancy rates (generally 1–2% in European samples) provides a biological measure of infidelity, though media overestimates are common.

Did You Know?

• The Kinsey Reports found that around half of men and a quarter of women studied had committed adultery.
• The General Social Survey has shown approximately 12% of men and 7% of women admit to having had an extramarital relationship.
• One study found that men are more likely to engage in infidelity while their partner is pregnant, with an estimated 1 in 10 fathers-to-be doing so.
• Paternal discrepancy is generally 1–2% among European samples, despite media assumptions of rates as high as 30%.