It's an old chestnut that you're only as old as you feel, but recent science has shown this cliche is also literally true. Our attitudes and expectations about aging play an important role in how fast our bodies age. Those who retain a youthful frame of mind have strong bodies and sharp minds for longer than those who feel their years more.

That means thinking like a young person can make you actually age more slowly. So how do you keep yourself feeling youthful?

The smarter you were then, the younger you feel now.

French researchers recently found a surprising answer to that question -- be more intelligent. The smarter you were as an adolescent and young person, their new study found, the younger your "subjective age" (a.k.a., how young you feel) when you're in your 70s. Intelligence seems to slow down aging.

Oh great, you might respond. That's fabulous for young geniuses. But exactly how can it help those of us who have passed beyond youthful and/or could never boast an above- average IQ? As an interesting recent British Psychological Science post from writer David Robinson explains, these findings actually suggest ways all of us can try to hold on to youth a bit longer.

Insight for the rest of us.

After establishing this somewhat odd correlation, the French researchers, led by Yannick Stephan of the University of Montpellier, wanted to figure out why. What about intelligent young people turns them into slower-aging older folks?

Lots of factors are likely in play. Smarter people might simply make better health decisions, for instance, so more study is needed to untangle causation. But the researchers also "found that greater 'openness to experience,' which is associated with having a higher IQ, seemed to be important. Perhaps a higher IQ, which helps us to process complex information more easily, also increases our curiosity about the world, and it's that sense of wonder and excitement that can make us feel more youthful," writes Robinson.

Let's break that down a little: smarter people tend, on average, to also be more open to new experiences. And it's not a huge shock that having new experiences and feeling wonder at the world are associated with a youthful outlook. That curiosity and playfulness, in turn, may actually slow physical aging. Or to put it bluntly, thinking like a kid actually helps you feel like a kid. That's not nearly as counterintuitive a statement as "smart people age more slowly," but it's also a far more useful one.

Openness to new experiences is one of the "Big Five" personality traits and, as such, is pretty stable over your lifetime, but personality is actually more malleable than many people realize. Those who crave stability and routine will probably never become wild and crazy adventurers, but it is very possible to nudge yourself to try more new things and keep your mind open to new ideas, no matter what your IQ score or personality type.

The other impressive benefits of openness to new experience.

This new science suggests this incredibly simple intervention can help you feel younger not only mentally, but also physically. And that's just the start of the benefits of retaining a thirst for novelty as you get older. Other science shows the more new experiences we have, the slower time seems to flow by. So if you want to stop the years passing in a flash, breaking out of your routine and seeking out novelty is key.

Openness is also the personality trait most closely associated with creative genius. So while trying a new lunch joint or opting for an unexpected vacation destination won't turn you into Picasso, it will almost certainly boost your creativity and help you see the world and solve problems in fresh, new ways.

Let's run through all that again. Simply by consciously choosing to bring more openness and new experiences into your life, you can slow aging, keep time from flying by, and significantly increase your creativity. Those are some pretty powerful effects for a painless (if not downright fun) intervention.

When was the last you tried something completely new and original?