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Turning 30, 40, or 50 Next Year? Read This

By Carol Church, Writer, Family Album
Reviewed by Heidi Radunovich, PhD, Department of Family, Youth, and Community Sciences, University of Florida

Do you know anyone who’s training to run a marathon? I certainly do. Lately, in fact, it seems like almost everyone I know has taken up running. Some are just hoping to get through their first 5K, but many are aiming for that 26.2-mile marker.

Running for fitness has definitely become more popular in the past few years, but according to a recent article in the Proceedings of the National Academy of Science, I may also know a lot of marathoners due to my age. You see, many of my friends are either just about to turn 40, or just over that hill. In this paper, researchers found that so-called “9-enders”—people going from one decade to the next, as from 30 to 40—do seem to act differently from the rest of us in various ways. And yes, that includes their behavior around marathons.

9-Enders: Not The Same as the Rest of Us

First, the scientists considered a huge sample of more than 40,000 adults from over 100 countries. They were asked how often they thought about their “meaning and purpose” in life. Nine-enders reported thinking about these topics significantly more often than those whose ages ended in another digit.

As for the runners, the scientists hypothesized that people would be more likely to enter their first marathons during a 9-ender year, and to run faster in marathons during those years (an indication of training harder). When they looked at data from various publicly accessible databases, this did indeed turn out to be true.

There’s a Dark Side

Both of these activities seem quite innocent—even productive. But the researchers also looked at two other behaviors that are far less positive. In one case, they obtained data from an online dating website whose target market is people who are already dating or married–and looking to “cheat.” Once again, “9-enders” were statistically overrepresented.

And in the darkest finding of all, researchers also pulled national data from the CDC on people who committed suicide from 2000 through 2011. As before, 9-enders were more common than they should have been by mathematical chance.

Decade Shifts May be in the Mind, But They Matter

What should we make of these indicators that people on the cusp of a new decade act differently from the rest of us? In many ways, this information probably doesn’t come as a surprise. Although there is, of course, no real difference between turning 39 or 41 and turning 40, humans tend to invest “round numbers” with more meaning, prompting us to examine our lives. For some, dissatisfaction leads to a generally productive response, like training for a marathon. For others, destructive impulses may follow.

This research may serve as a reminder to keep an eye on friends, loved ones, and even ourselves as we approach those milestone birthdays we often like to joke about. If you or someone you know is responding to an upcoming birthday with despair, depression, or anxiety, it may be time to speak to a physician or consult a therapist. For assistance in locating a therapist, try the American Psychological Association’s Therapist Locator, or search for licensed psychologists in your area of Florida using the Florida Department of Health’s search service. (If you do not live in Florida, search for your state’s Department of Health website, which likely has a similar feature to help consumers locate licensed psychologists.)

(Photo credit: Cake by Dave HaygarthCC BY 2.0. Cropped.)

References:

Alter, A. L., & Hershfield, H. E. People search for meaning when they approach a new decade in chronological age. Proceedings of the National Academy of Science, 111(48), 17066-17070. http://www.pnas.org/cgi/doi/10.1073/pnas.1415086111