LIAR, LIAR

* People tend to broadcast their true feelings through the upper part of the face.

* When a person is being dishonest, certain tissues in the nose swell.

* Liars tend to blink less than those telling the truth.

TRUTH BE TOLD

Police and other law enforcement officials are always looking for reliable ways to separate the Pinocchios from the honest Abes. Traditionally, they've used lie detectors, also called polygraph tests, to measure truth-telling by monitoring a person's physical reaction to a series of questions. Although a polygraph isn't perfect (and not admissible in court because the physical reactions measured can be attributable to other factors), it works on the principle that the body involuntarily reacts to emotion. When you know you're fibbing, you become nervous, stimulating an increase in your sympathetic nervous system's activity and production of a hormone called epinephrine. These changes cause the 2.6 million sweat glands in your skin to start sweating, your lungs to speed up breathing, and your heart to pump blood faster and contract with greater force.

Since polygraphs aren't all that accurate, researchers are always looking for other ways to pinpoint pretenders. They've invented thermal imaging cameras to measure heat around a person's eyes, devices that measure stress level in a person's voice, and more. The American Psychiatric Association compiled a list of 23 physical and verbal signs that a person is lying, including increased leaning forward, touching the nose, and clearing of the throat. Researchers have even discovered a few people they label human lie detectors. These "wizards" use physical cues and nuances to determine truthfulness with amazing accuracy.

WAKE UP CALL

The Torah describes a person with a spiritual illness, called tzara’at, who is afflicted with white splotches on the skin for having spoken improperly. Before coming down with tzara’at, God first afflicted the person’s house and clothing as warnings to the person to change his or her ways. Only if the person ignored these wake-up calls did he or she come down with a full-fledged case of tzara’at. Today, when we lie or speak lashon hara (evil speech, including gossip), no mysterious white patches appear on our skin, our clothes, or our houses, but we do come down with a slew of other physical symptoms, including sweaty palms and stress in our voices. They are very subtle hints, but noticeable enough to serve as a wake-up call that it’s time to cleanse ourselves of the spiritual sicknesses caused by lying.