According to NBC News, 22 percent of men and 15 percent of women in monogamous relationships have committed adultery. This statistic was taken from the "American Sexual Behavior" study, which involved 10,000 people over a 20-year period.
In 1992, the National Opinion Research Center in Chicago conducted face-to-face interviews with 3,432 U.S. adults between the ages of 18 and 59 and asked if they had ever committed adultery. One quarter of the men and a sixth of the women admitted to cheating at least once. However, nearly 90 percent of men and 94 percent of the women surveyed believed that adultery was "always" or "almost always" wrong.