Is 49 the Age Guys Are Most Likely to Cheat?

Photo: Sigrid Gombert/Westend61/Corbis

In a new paper that does nothing to quell the myth of the midlife crisis, two researchers argue that men are most likely to cheat in their marriages the year before they begin a brand-new decade: ages 29, 39, 49, and 59. And, as you can see from the accompanying chart, the wandering-eye urge seems to spike at age 49. (There's a bump at 33, too, incidentally.)

The researchers used data from Ashley Madison, the site that caters to people seeking affairs, and found that of the more than 8 million male users ages 25 to 64, more than 950,000 were in their last year of a decade, which is about 18 percent more than chance would dictate. They also examined data from women who used the site, and although they found a similar trend, the effect wasn't as strong. In other words, this is mostly a dude thing. It’s an interesting attempt to quantify a feeling most of us can identify with — that search for existential meaning before a big birthday. (We covered the full paper over at Science of Us earlier this week, if you're curious to read more about it.)