Do facial expressions influence our emotional state?

When we’re happy, our bodies become flooded with dopamine and serotonin, two types of neurotransmitters in the brain; our hearts might even beat faster and maybe, we even muster a smile.

But does it work the other way? Can contorting our faces into a smile give us that chemical hit that actually makes us feel good?

Nicholas A. Coles from the Center for the Study of Language and Information at Stanford University joins