When I saw an article on smiling, I didn't think there could be much to write about, but I was wrong. In The Untapped Power of Smiling, Ron Gutman reveals quite a few interesting facts about smiling. Among them:
A Wayne State University research project
"examined the baseball cards photos of Major League players in 1952.
The study found that the span of a player’s smile could actually predict
the span of his life!"
"Have you ever wondered why being around children who smile frequently makes you smile more often? Two studies
from 2002 and 2011 at Uppsala University in Sweden confirmed that other
people’s smiles actually suppress the control we usually have over our
facial muscles, compelling us to smile. They also showed that it’s very
difficult to frown when looking at someone who smiles."
a study conducted in the UK (using an electromagnetic brain scan
machine and heart-rate monitor to create “mood-boosting values” for
various stimuli), British researchers found that one smile can provide
the same level of brain stimulation as up to 2,000 chocolate bars; they also found that smiling can be as stimulating as receiving up to 16,000 Pounds Sterling in cash."