Microexpressions
A microexpression is a brief, involuntary facial expression shown on the face of humans according to emotions experienced. They usually occur in high-stakes situations, where people have something to lose or gain. Microexpressions occur when a person is consciously trying to conceal all signs of how they are feeling, or when a person does not consciously know how they are feeling. Unlike regular facial expressions, it is difficult/impossible to hide microexpression reactions. Microexpressions cannot be controlled as they happen in a fraction of a second, but it is possible to capture someone's expressions with a high speed camera and replay them at much slower speeds. Microexpressions express the seven universal emotions: disgust, anger, fear, sadness, happiness, contempt, and surprise. Nevertheless, in the 1990s, Paul Ekman expanded his list of emotions, including a range of positive and negative emotions not all of which are encoded in facial muscles. These emotions are amusement, embarrassment, anxiety, guilt, pride, relief, contentment, pleasure, and shame. They are very brief in duration, lasting only 1⁄25 to 1⁄15 of a second.
Microexpressions were first discovered by Haggard and Isaacs. In their 1966 study, Haggard and Isaacs outlined how they discovered these "micromomentary" expressions while "scanning motion picture films of psychotherapy hours, searching for indications of non-verbal communication between therapist and patient" Through a series of studies, Paul Ekman found a high agreement across members of diverse Western and Eastern literate cultures on selecting emotional labels that fit facial expressions. Expressions he found to be universal included those indicating anger, disgust, fear, happiness, sadness, and surprise. Findings on contempt are less clear, though there is at least some preliminary evidence that this emotion and its expression are universally recognized. Working with his long-time friend Wallace V. Friesen, Ekman demonstrated that the findings extended to preliterate Fore tribesmen in Papua New Guinea, whose members could not have learned the meaning of expressions from exposure to media depictions of emotion. Ekman and Friesen then demonstrated that certain emotions were exhibited with very specific display rules, culture-specific prescriptions about who can show which emotions to whom and when. These display rules could explain how cultural differences may conceal the universal effect of expression.
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