Fifty-six percent of men who had affairs were happy in their marriage, according to a study by Helen Fisher, PhD, a biological anthropologist at Rutgers University and the author of
Why Him? Why Her?
Why We Love.
By comparison, only 34% of women who had affairs were happy or very happy in their marriage.
Men are more likely to give sexual motivations for infidelity and less likely to fall in love with an extramarital partner, Fisher tells WebMD. "Women are more interested in supplementing their marriage or jumping ship than men are. For men, it is a secondary strategy as opposed to an alternate."