ABSTRACT
Nonverbal behavior, especially facial expression, has been highly significant in the understanding of emotions. For some authors, the association of particular facial movements with particular emotions suggests that they literally express, or provide a 'read-out', of one's inner emotional state. However, it is clear that the people manage their facial behavior in ways which might be called impression management, or deception. It fits better with the analysis of other signals to talk of facial behavior as communicating emotions, rather than as expressing them. It is known that the neural pathways controlling spontaneous facial expressions are different from those that control voluntary facial behavior. It has been suggested that certain signals emitted to mislead another animal can be classed as deception. People share common beliefs about what are the verbal and nonverbal cues that reveal emotion. The idea is that lying causes an increase in physiological arousal which the operator can then identify.
