CONCEPT
Microexpressions
The fleeting, sub-second involuntary emotional leakages that
Paul Ekman believed revealed concealed feelings—and the most consequential, most misused, and most carefully caveated concept in the science of the readable face.
A microexpression, as
Paul Ekman defined it, is a facial expression lasting a fraction of a second—too fast for most observers to consciously notice, too fast to fake—that flashes across the face when a person feels an emotion they are motivated to conceal and then suppresses it. Ekman discovered them through slow-motion review of clinical film, and they captured the public imagination as almost nothing in modern psychology had: the idea that the truth of feeling will out, involuntarily, in a flicker the controlled face cannot hold back. They became the conceptual seed of automated deception detection, the intellectual prop of a security screening program, and the premise of the television series
Lie to Me. They also came with a crucial caveat that the industry absorbed the concept without: a microexpression reveals a
concealed emotion, not a lie. A truthful person under suspicion may feel intense fear; that fear may leak as a microexpression indistinguishable from the guilty person's fear of being caught. The signal is