Is There a Way to Tell When Someone Is Lying?

Judges, defense attorneys, wronged spouses and suspicious parents would love to be able to definitively know if a certain person is lying. The polygraph, or lie detector, is one machine that purports to tell testers whether the test subject is lying or not. However, depending on whom you ask, the machine's accuracy ranges from about 70 to 90 percent, which is why polygraph results are rarely admissible in court. However, as we learned from Pinocchio, an individual's nose may hold the key to whether he or she is speaking the truth.

So, is there any foolproof way to tell when someone is lying? The answers are as varied as the opinions on polygraph accuracy. The Department of Experimental Psychology at the University of Granada think they know of a pretty accurate test. Dubbed the "Pinocchio Effect," the test involves a thermographic camera that shows body heat variations. Their results indicate that when a person lies, the area around his or her nose and eyes gets warmer. The thermographic camera can detect when the area around the nose gets warmer, potentially revealing when people lie about their feelings. Most courtrooms, however, don't have these cameras for their witnesses, so methods to determine whether a person is lying will continue to develop.

Some ways to tell whether a person is lying:

• Inconsistent story. Someone who is lying may tell a story with unsolvable inconsistencies. This is a good indication the person is not telling the truth.
• Look for emotions that seem insincere. For example, look at a person who is smiling and see if the smile matches the rest of the face. Another false emotional display involves "crocodile tears," where someone may be crying, but the emotions aren't real.
• Too much detail is as telling as too little. Someone who has an extremely detailed story to tell about a potentially fictitious event may have put a great deal of thought into it, and so will include many unimportant details.