I am always so astounded at TED talks. Every person that shares has added to my knowledge of the world around me and my added to my understanding of life and all its many facets.
The fact that a smile has so much power is rudimentary, it is so hardwired into us that as Ron points out, Even unborn babies smile and you can't help but smile back.
It's interesting to note that many of the animal species react very differently to exposed teeth (regardless of intent lol) as it is seen as a predatory or hostile in nature, but amongst humanity it is sign of happiness, of exceptance and understanding, of an emotion shared, an emotion of joy.
What is it about us that we can find such comfort, happiness, closeness from so simple a thing as an upward turn of the lips, a gleam in the eyes, a warmth that radiates from this simple gesture?
I don't think I really want to know.
I'm happy just knowing how much power a single smile can have, to change a heart, to share in a joy, to save a life.
A smile, is in fact, everything that makes us so unique, and so Human.