The Kinsey Institute: Infidelity & Affair Statistics
The Kinsey Institute offers the following information about infidelity and affairs:
- Infidelity has been found to be the single most cited cause of divorce in over 150 cultures. (Betzig, 1989)
- In western countries, between 25 and 50% of divorcees cite a spouse’s infidelity as the primary cause of the divorce. (Kelly, 1987; Amato, 1997)
- Approximately 20-25% of men and 10-15% of women engage in extramarital sex at least once during their marriage. (Laumann, 1994; Wiederman, 1997)
- Pregnancy appears to be a time of increased risk of extramarital sex. (Allen, 2005; White, 1982)
- Women are less approving than men of sexual justifications for extramarital affairs, preferring emotional reasons such as “falling in love”. (Glass, 1992).
- Approximately 50% of divorced men and women reported that their former spouse had engaged in extra-marital sex. For divorced couples, previous participation in extramarital sex showed no effect on post-marital adjustment. (Spanier, 1982).
- 11% of adults who have ever been married or cohabited have been unfaithful to their partner (Treas & Giesen, 2000).
- Infidelity is influenced by many social and demographic factors. All of the following were associated with an increased risk of infidelity: having been part of a couple for a long time; having had a high number of prior sex partners; being male or black; living in a central city; and thinking about sex several times a day (Treas & Giesen, 2000).
- Respondents who reported that their relationships were “pretty happy” and “not too happy” were two and four times more likely, respectively, to have reported extramarital sex than respondents who reported that they were “very happy” with their relationships (Atkins et al., 2001).
- More than 80% of women and 65 to 85% of men report that they had no partners other than their spouse while they were married (Laumann, Gagnon, Michael, Michaels, 1994).
- 94% of married men and women had only one sex partner (their spouse) in the past 12 months, 4% had 2-4 partners, and 1% had over 5 partners (Laumann, Gagnon, Michael, Michaels, 1994).