Wrinkles should merely indicate where smiles have been.
I have been interested in the art of smiling since my first graduate school paper The Biological and Maturational Development of the Smile in the Neonate. You don’t really want to know how long ago that was, but to give you a rough idea — I wrote it while wearing my bellbottoms.
Back then I learned that infants initially smile as a type of reflex, almost as a way of getting them jump-started, but very soon afterward that grimace emerges into a social smile. They learn how to engage their caretakers, get some attention, be loved and, most importantly, survive. This means that a social smile has Darwinian value. But more than survival, a smile may be the doorway into understanding what brings us the good life.
Researchers LeeAnne Harker and Dacher Keltner (2001) analyzed college yearbook photographs of women displaying what is known as a Duchenne smile — an honest, genuine, bona fide smile — versus a non-Duchenne smile.
The Duchenne smile was named after Guillaume-Benjamin-Amand Duchenne de Boulogne, who, speaking of Darwin, greatly influenced Darwin’s book, The Expression of the Emotions in Man and Animals.
Duchenne was a French neurologist interested in determining how the physiognomy of the face produced facial expressions, which he thought were directly linked to the soul. His investigations involved electricallt stimulating various muscles and identifying corresponding emotions. Along the way he identified a particular type of smile that engages both the zygomatic major and the orbicularis oculi — muscles that raise the corners of the mouth and cheeks, respectively. In other words, a big, genuine smile contracts the corners of our mouth and eyes.
Since we humans can’t voluntarily control the outer contraction of the orbicularis oculi — the muscle that gives us the “crow’s feet” — a smile that produces uplift at the corners of the eyes is considered to be more genuine. If you only produce a smile that turns up the corners of the mouth … well, as Duchenne may have said, the source of pleasure ain’t coming from your soul. In essence, the non-Duchenne smile is contrived, whereas the genuine smile seems to emanate from a deeper connection to one’s joy.
In the longitudinal study of Mills College graduates, Keltner and colleague LeeAnne Harker coded the smiles of 114 women who had their university yearbook photo taken sometime during 1958 and 1960. All but three of the young women smiled. However, 50 had Duchenne smiles and 61 had non-Duchenne, courtesy smiles.
The genuine smile group were more likely to get and stay married, and had higher score evaluations of physical and emotional wellbeing. Remarkably, Keltner’s study was able to find this connection more than 30 years after the college photos were taken. As in the famous Nun Study, where essays written by young women hoping to enter a convent were analyzed for their positive phrases, these early indications of upbeat emotions had predictive validity of future wellbeing.
In both the Nun Study and the Mills College research a measure of early positive expression, one through writing and one through smiling, determined the effect of this positivity over the lifespan. Could it really be that a paragraph or a smile expressed in young adulthood really denotes our outlook on life?
Whether expressed in an essay or a genuine smile, our future wellbeing seems predictable. This in and of itself would be interesting news, but there’s more: How intensely you smile may predict exactly how good of a life you are going to have.
In a 2009 study entitled Smile Intensity in Photographs Predicts Longevity, researchers Ernest L. Abel and Michael L. Kruger were able to demonstrate that people with positive emotions throughout the lifespan are happier, have more stable personalities, more stable marriages, and better cognitive and interpersonal skills than those with negative emotions. But it isn’t even what they were studying was so intriguing, it was whom they studied.
It wasn’t nuns or young women in college — it was Major League Baseball players. Data on their lives and photographs from the Baseball Register from 1952 were available for study. What the researchers found was that of the 230 images and individuals they studied, they identified the Duchenne smile, but with the addition of smile intensity — including a partial smile and no smile — as a factor. The results are in line with hosts of other studies demonstrating that positive emotions correlate with variables including mental and physical health and longevity.
Abel and Kruger concluded that the quality and intensity of the baseball players’ smiles predicted how well they scored on the variables listed above. Most notably, how well they smiled predicted how long they lived.
So the next time you are going to have your picture taken, smile as if your life depends on it. And if you can only give us that non-Duchenne smile of yours, then you may want to follow the wisdom of W. C. Fields, a man who knew a thing or two about making people grin: “Start every day with a smile and get it over with.”