And then there are the staged smiles: the ones that express politeness, contempt, or restraint. These forced smiles employ a different set of facial muscles than the happy ones.

New research suggests that different types of smiles have different effects. Words in The News: 2 June 2010 ...

What's in a grin? A lot, apparently. Body language Patti Wood breaks down the different types of smiles, and when you may see them.

Researchers have identified three distinct, reliably recognised expressions of smile -- reward, affiliation and dominance -- and the facial muscle combinations that make them. Each smile hinges on ...

A study by UW-Madison defined the facial movements in smiles that we use to navigate different social interactions.

However, more recent findings paint the Duchenne smile in a different light. First, there’s the discovery that, contrary to popular belief, it can be faked.