Scientists have pinpointed more than 50 types of smiles, and research suggests that the sincerest smile of all is the Duchenne smile--a smile that pushes up into the eyes.[1] The reason it's more genuine is because the muscles needed to smile with our eyes are involuntary; they only become engaged in an authentic smile, not in a "courtesy" smile.[2] Since you can't force a genuine smile (after all, that's what makes them genuine!) this article will suggest some ways you can smile from within

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