Entering a New Decade in Life Makes People Want to Cheat

If your current age ends in eight, prepare to freak out. A new study published in Proceedings of the National Academy of Sciences has found that people when they’re 29, 39, 49, or 59, tend to be more likely to cheat on their significant others or pick up jogging.

Called “nine-enders” (those whose age ends in a nine), research shows that this 12-month transition period in one’s life is, put simply, incredibly intimidating. When someone is nearing the end of decade it’s more probable that they’ll make a large purchase, buy life insurance, invest in retirement savings, or even go under the knife for cosmetic enhancements.

These individuals are more likely to engage in extremely productive behavior before their birthdays such as running a marathon, going back to school. But things tend to skew to the other side of the spectrum as well with those about to cross into their 30s, 40s, 50s or 60s are more prone to picking up socially destructive habits as well.

Most interesting, looking at the extramarital dating site Ashley Madison, lead study authors Adam Alter and Hal Hershfield discovered that there were more than 950,000 men aged 29, 39, 49, or 59 using the service. Interestingly, that’s about 18 percent more than would be users just by happenstance.

“People are more apt to evaluate their lives as a chronological decade ends, and, as a result, more likely to make life-altering decisions,” explain the authors. “As we age, it’s good to understand this propensity so we’re more likely to make constructive rather than destructive choices.”

The midlife crisis is real people — it just needs a new definition.