Cheating is pretty frowned upon in modern society. We’re one-partner mammals, so the act of being unfaithful should be a slim-to-none occurence, right? But it happens, and it sucks. However, would it be as bad if it were rooted in evolutionary biology? According to a study in Personality and Individual Differences, that might actually be the case.
Switching mates, or having back-up mates, was a way for ancestral women to “pursue the highest value partners she could attract and retain,” according to the study. This stems from the volatile and dangerous environment of that age, such as other species, environmental hazards, and other humans. By having multiple mates, a woman could have more security in protection and resources. There was also the issue of vastly shorter lifespans, meaning a woman’s partner could die almost any day.
David Buss, an author of the study and a professor of evolutionary psychology at the University of Texas, said: “Affairs serve as a form of mate insurance, keeping a backup mate should a switch become warranted in the future. A regular mate may cheat, defect, die, or decline in mate value.”
By having multiple mates, a woman could have more security in protection and resources.
But, while the study does focus on women more than men, men aren’t entirely exempt. Us guys have genetic predispositions to stray from partners, as it increases the chance male genes will be spread.
Surveys have also found that a vast majority (91%) of pollers said that cheating was morally wrong, but about 21% of married men and between 10 and 15% of married women admitted to cheating in the last 20 years. “Lifelong monogamy does not characterize the primary mating patterns of humans,” Buss told the NY Times. “Breaking up with one partner and mating with another may more accurately characterize the common, perhaps the primary, mating strategy of humans.”