I wonder how valid these 19 tips really are, given the differences in smiles between nationalities. http://www.slate.com/articles/health_and_science/science/20

I wonder how valid these 19 tips really are, given the differences in smiles between nationalities. http://www.slate.com/articles/health_and_science/science/2012/07/olympic_smiles_how_to_identify_athletes_nationalities_based_on_their_facial_expressions_.html http://www.slate.com/articles/health_and_science/science/201...