Smiles are strange things. People use them when they are happy, yes, but also when they are uncomfortable, bored, anxious, or trying to be polite. Sometimes a smile has nothing to do with joy at all.

Many smiles are socially motivated, used to appear polite, reduce tension, or mask discomfort. Scientists have long studied how the human brain distinguishes between real and fake smiles, revealing ...

The horror movie "Smile" has been racking it up at the box office, which got me thinking about how many people hate smiles. I’m not talking about terrifying psychopath smiles or creepy clown smiles.