After surveying 423 people, the researchers discovered that women who were married between six to 10 years were most likely to consider engaging in an extramarital affair. The picture was pretty different for dudes: As the time they were married increased, so did the likelihood that they would entertain the option to stray. In fact, men who had been married 11 or more years reported the greatest willingness to allow an intimate encounter to develop with someone other than their spouse.
So what did men and women consider as cheating anyway? The least likely behaviour the participants counted as cheating was viewing porn, followed by a one-time instance of flirting with an unfamiliar person, and then multiple instances of flirting with that person.
The more physical and continuous the behaviours got, the more likely they were to be considered infidelity. For instance, the participants rated “multiple instances of intimate physical content with the same extramarital companion” as the behaviour most indicative of cheating—slightly ahead of a single sexual incident, and multiple instances but with different companions.
So why are women more likely to cheat in that 6 to 10 year window? It may be because when the marriage is in its early states, it’s likely that any children are still young and vulnerable, the study authors believe. So at this stage, investment in the family still serves as a strong barrier against straying.
But as time goes on, the evolutionary drive to seek out more partners—as a possible way to produce more children—outweighs the desire to invest in rearing the kids who already exist. Factor that in with looming menopause, and that may help explain why women are tempted to cheat during that time.
Still, that’s a very evolutionary explanation—what about real life? Turns out, there are a number of reasons why women admit they cheat. One big reason that can play a role is ageing. She begins to reflect on the things she has or hasn’t achieved over the past decade or so, which can lead to bleak thoughts, quality-of-life researcher Michael Steger, Ph.D. told us in the past.
Additional reporting by Mike Darling
This article originally appeared on Men's Health.