What is in a smile? | Neuro-patch
We distinguish genuine from fake smiles, even though we appreciate the polite sort of fake smile in many cases. I have thought it was a settled matter. Smiles are marked by the raising of the corners of the mouth and pulling them back. A broad smile (fake or real) opens the mouth by lowering the jaw. But only authentic smiles are marked by crow's feet at the corners of the eyes. This is the Duchenne marker. Would you believe that it is just not that simple? The smile is a dynamic thing and research has mostly used static pictures to investigate smiles. A recent paper by Korb (citation below) examines dynamic smiles. Here is the abstract: "The mechanisms through which people perceive different types of smiles and judge their authenticity remain unclear. Here, 19 different types of smiles were created based on the Facial Action Coding System (FACS), using highly controlled, dynamic avatar faces. Participants observed short videos of smiles while their facial mimicry was measured