How Does The Duration Of A Relationship Affect The Likelihood Of Cheating?

Dr. Justin Lehmiller decided to find out how the likelihood of cheating is related to the duration of the relationship. Basically, he wanted to know if cheating is more or less common when you look at couples who have been together for a very long time.

The first work he relied on was a recent study published in the Journal of Sex Research. A total of 313 Israeli adults (average 32-33 years old) were interviewed, all of whom were heterosexual and had been married for at least one year. Participants were asked about their infidelity, and researchers looked at how this was related to the length of the marriage.

The participants were divided into three groups: short marriages (<5 years), intermediate (6-10 years) and long-term marriages (11+ years). The group that reported the highest likelihood of cheating was the long-term group; the short-term group reported the lowest odds, and the intermediate group fell in between. In other words, the longer a couple has been together, the more likely it is that they will cheat.

However, the picture was slightly different for men and women. Specifically, for men, the chances of cheating increased as the relationship continued (that is, what scientists call the linear effect). For women, however, the effect was curvilinear, with women reporting the highest chances of cheating in intermarriage, but with lower chances of cheating in short and long term marriages. In other words, both men and women seemed to get the so-called "seven-year itch": the pursuit of new sensations after seven years of marriage. True, for women this passed, but for men it only worsened.