What is a Micro-Expression?
A micro-expression occurs when a person tries to hide their emotions, where a "very brief (1/5th to 1/25th of a second) facial expression often occurs, [and is] invisible to nearly everyone who has not been trained to detect micro-expressions" ("Micro-Expressions"). Micro-expressions are very hard to conceal since the emotion occurs at such a fast rate. Producing a micro-expression is nearly impossible for the same reason. People lie for a wide range of reasons, but the top few reasons include "to avoid being punished for breaking a rule, law, etc." and "to get something more easily or not otherwise obtainable without lying" ("How to", para 1). The consequences of lying has more of a chance to fail when the stakes are higher. As can be seen in Figures 1 and 2, there are seven universal expressions in the face: happiness, surprise, contempt, sadness, fear, disgust, and anger.
These expressions will be explained in more detail later in the paper.
Figure 1. Micro-Expressions with Description Figure 2. Seven Facial Micro-Expressions
The History of Micro-Expressions
Before all of the researchers and studies, Charles Darwin had the most research on facial expressions, saying facial expressions are linked to our emotions. The book on Darwin's study of micro-expressions is The Expression of Emotions in Man and Animals ("Micro-Expressions,"). Matsumoto & Hwang notes that Darwin proposed that people's expressions are universal and biologically instinctive.
The next research done on micro-expressions was made by Haggard and Isaacs in 1966 by "scanning motion picture films of psychotherapy hours, searching for indications of non-verbal communication between patient and therapist," ("Microexpressions," para 2) while calling them "micromomentary expressions" instead of micro-expressions.
According to Matsumoto & Hwang, in 1974, Ekman and Friesen examined hours of frame...