Universal facial expressions
Research suggests the existence of seven universal emotions, each of which is associated with a distinct facial expressions: happiness, surprise, sadness, fright, disgust, contempt, and anger.
Source
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"CNX Psychology, Psychology. July 27, 2015."
http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:58/Psychology
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