Only one-third of us smile more than 20 times a day. Unbelievable. And yet smiling reduces stress and helps us live a longer, happier life – amongst other things. It’s time to get smiling people!

Ron Gutman reviews a raft of studies about smiling, and reveals some surprising results. Did you know your smile can be a predictor of how long you’ll live — and that a simple smile has a measurable effect on your overall well-being? Prepare to flex a few facial muscles as you learn more about this evolutionarily contagious behavior. See more: TED.