Deception

Everyone has experienced deception. It would be nearly impossible to find someone who has neither lied nor been lied to. Although it has negative connotations, deception constitutes a major portion of communication. In fact, depending on which survey you consult, most people will admit that they have lied in the last few months. Several nonverbal behaviors have been identified with deception. A change in the amount of eye contact is one indication of deception. You are usually aware of how much someone you know makes eye contact with you while talking. If the acquaintance's eye behavior changes, it could he an indication of deception. Deceivers engage in more leg and foot movements and shift posture more than honest people. Liars tend to tap their feet nervously, swing their legs, or squirm in their chairs. Stress-related behaviors are another indication of deception.

One of the best identifiers of a liar is voice pitch; vocal pitch has a tendency to rise when one is telling a lie, and it is not easily controlled by the deceiver. Another physical characteristic that the deceiver cannot control is pupil dilation; the pupils have been found to dilate during lying. Other nonverbal cues that have been consistently linked with deceivers are blinking, speech errors and hesitations (stammering, problems with pronunciation, unusually long pauses between words or sentences), and channel discrepancies. A channel discrepancy is the use of two or more channels to send contradictory or inconsistent messages. Examples including saying "I'm not nervous" while one's hands are shaking, and saying "I love you" with a smirk on one's face. When faced with channel discrepancies, most people believe the nonverbal rather than the verbal cues.

The deceiver's cues are affected by his or her personality, motivation, planning and age. Nonverbal behaviors vary according to whether the deceiver has prepared a lie or is relating a spontaneous lie. The deceiver who is delivering prepared lies will show greater anxiety, arousal, and stress because the deceiver has had time to worry about the outcome of the lie. Spontaneous lies, produced on short notice, will solicit nonverbal behaviors such as rubbing and scratching.