microexpressions are not very different from macroexpressions in the muscles that are involved; the main difference is in their speed. Ekman demonstrated, however, that these quick flashes of muscle contraction are so fast that people miss them: ninety-nine percent of people were unable to perceive them. Nevertheless, he also claims that people can be trained to look for microexpressions and in particular learn to detect liars, a classic example of saying one thing and feeling another.
