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.

You've probably heard the claim that it takes more muscles to frown than to smile. It's usually framed as a feel-good reason to turn your frown upside down—less effort, more joy. But anatomically, the ...

Ever noticed how there are basically two types of smiles: a genuine smile and a fake one? This distinction has been of interest to researchers for quite some time now. In fact, the genuine smile has a ...