When I was a child, I always wanted to be a superhero. I wantedto save the world and then make everyone happy. But I knew that I'd needsuperpowers to make my dreams come true. So I used to embark on these imaginaryjourneys to find intergalactic objects from planet Krypton, which was a lot offun, but didn't get much result. When I grew up, and realized thatscience-fiction was not a good source for superpowers, I decided instead toembark on a journey of real science, to find a more useful truth.
I started my journey in California with a UC Berkley 30-year longitudinal studythat examined the photos of students in an old yearbook and tried to measuretheir success and well-being throughout their life.
By measuring their studentsmiles, researchers were able to predict how fulfilling and long-lasting asubject's marriage will be, how well she would score on standardized tests ofwell-being and how inspiring she would be to others. In another yearbook, Istumbled upon Barry Obama's picture. When I first saw his picture, I thoughtthat these superpowers came from his super collar. But now I know it was all inhis smile.
Another aha! moment came from a 2010 Wayne State University research projectthat looked into pre-1950s baseball cards of Major League players. Theresearchers found that the span of a players smile could actually predict thespan of his life. Players who didn't smile in their pictures lived an averageof only 72.9 years, where players with beaming smiles lived an average ofalmost 80 years.
The good news is that we're actually born smiling. Using 3Dultrasound technology, we can now see that developing babies appear to smile,even in the womb. When they're born, babies continue to smile -- initially,mostly in their sleep. And even blind babies smile to the sound of the humanvoice.
好消息是，我们天生就会微笑 通过三维超声波技术 我们可以看到，即使在子宫中，正在成形的胎儿 似乎也是面带微笑的 出生之后 他们还是带着微笑——他们大多在睡梦中微笑 失明的婴儿 听到人声时也会微笑。
Smiling is one of the most basic, biologically-uniform expressions ofall humans.
In studies conducted in Papua New Guinea, Paul Ekman, the world's most renownedresearcher on facial expressions, found that even members of the Fore tribe,who were completely disconnected from Western culture, and also known for theirunusual cannibalism rituals, attributed smiles to descriptions of situationsthe same way you and I would.
微笑是全人类生理上最统一、 最基本的表情。在巴布亚新几内亚进行的研究中，Paul Ekman，世界上最知名的脸部表情研究者发现，即使是Fore部落中的成员，他们完全与西方文化隔绝，也因他们不寻常的吃人仪式而众所皆知，他们就像你我一样，也会在某些情况下微笑。
So from Papau New Guinea to Hollywood all the wayto modern art in Beijing, we smile often, and you smile to express joy andsatisfaction.
How many people here in this room smile more than 20 times perday? Raise your hand if you do. Oh, wow. Outside of this room, more than athird of us smile more than 20 times per day, whereas less than 14 percent ofus smile less than five. In fact, those with the most amazing superpowers areactually children who smile as many as 400 times per day.
Have you ever wondered why being around children who smile sofrequently makes you smile very often? A recent study at Uppsala University inSweden found that it's very difficult to frown when looking at someone whosmiles. You ask, why? Because smiling is evolutionarily contagious, and itsuppresses the control we usually have on our facial muscles. Mimicking a smileand experiencing it physically help us understand whether our smile is fake orreal, so we can understand the emotional state of the smiler.
In a recent mimicking study at the University of Clermont-Ferrand in France,subjects were asked to determine whether a smile was real or fake while holdinga pencil in their mouth to repress smiling muscles. Without the pencil,subjects were excellent judges, But with the pencil in their mouth, when theycould not mimic the smile they saw, their judgment was impaired.
In addition to theorizing on evolution in "The Origin ofSpecies", Charles Darwin also wrote the facial feedback response theory.His theory states that the act of smiling itself actually makes us feel better-- rather than smiling being merely a result of feeling good. In his study,Darwin actually cited a French neurologist, Guillaume Duchenne, who usedelectric jolts to facial muscles to induce and stimulate smiles. Please, don'ttry this at home.
In a related German study, researchers used fMRI imaging tomeasure brain activity before and after injecting Botox to suppress smilingmuscles. The finding supported Darwin's theory by showing that facial feedbackmodifies the neural processing of emotional content in the brain in a way that helpsus feel better when we smile. Smiling stimulates our brain reward mechanism ina way that even chocolate -- a well-regarded pleasure inducer -- cannot match.
British researchers found that one smile can generate the samelevel of brain stimulation as up to 2,000 bars of chocolate. (Laughter) Wait.The same study found that smiling is as stimulating as receiving up to 16,000pounds Sterling in cash. That's like 25 grand a smile. It's not bad. And thinkabout it this way: 25,000 times 400 -- quite a few kids out there feel likemark Zuckerberg every day.
And, unlike lots of chocolate, lots of smiling can actually makeyou healthier. Smiling can help reduce the level of stress-enhancing hormoneslike cortisol, adrenaline and dopamine, increase the level of mood-enhancinghormones like endorphin and reduce overall blood pressure.
And if that's not enough, smiling can actually look good in the eyes of others.A recent study at Penn State University found that when you smile you don'tonly appear to be more likable and courteous, but you actually appear to bemore competent.
So whenever you want to look great and competent, reduce your stress or improveyour marriage, or feel as if you just had a whole stack of high-qualitychocolate -- without incurring the caloric cost -- or as if you found 25 grandin a pocket of an old jacket you hadn't worn for ages, or whenever you want totap into a superpower that will help you and everyone around you live a longer,healthier, happier life, smile.