"Even the simulation of an emotion tends to arouse it in our minds." Charles Darwin, 1872The facial feedback hypothesis states that facial movement can influence emotional experience. For example, an individual who is forced to smile during a social event will actually come to find the event more of an enjoyable experience.Here's a lab that's dedicated to learning more about human facial expressions and the emotions they connotate.A smile is a facial expression formed by flexing the muscles near both ends of the mouth and by flexing muscles throughout the mouth. Some smiles include contraction of the muscles at the corner of the eyes (also known as 'Duchenne' smiling). Among humans, it is an expression denoting pleasure, sociability, happiness, oramusement. This is not to be confused with a similar but usually involuntary expression of anxiety known as a grimace. Smiling is something that is understood by everyone, regardless of culture, race, or religion; it is internationally known. Cross-cultural studies have shown that smiling is a means of communication throughout the world, but there are large differences between different cultures. A smile can also be spontaneous or artificial.Try to spot the fake smile here.Check out these babies smiling in their ultrasound pictures. Adorable!

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