Lie detection

Lie detection is an assessment of a verbal statement with the goal to reveal a possible intentional deceit. Lie detection may refer to a cognitive process of detecting deception by evaluating message content as well as non-verbal cues. People are generally not as good at detecting lies as they think they are. The average person can only detect lying with chance accuracy, and experts, including law enforcement, are not siginificantly better at it. There are a few reasons as to why we aren't very good at lie detection. Most people are decent liars and we tend to be overconfident in our ability to detect lies and the cues that someone is lying are usually very subtle and we are likely to look in the wrong place. The average person also does not expect others to lie to them, so we instinctively believe people are being truthful towards us.

Lie detection may also refer to questioning techniques used along with technology that record physiological functions to ascertain truth and falsehood in response. The latter is commonly used by law enforcement in the United States, but rarely in other countries because it is based on pseudoscience. There are a wide variety of technologies available for this purpose. The most common and long used measure is the polygraph. A comprehensive 2003 review by the National Academy of Sciences of existing research concluded that there was "little basis for the expectation that a polygraph test could have extremely high accuracy." There is no evidence to substantiate that non-verbal lie detection, such as by looking at body language, is an effective way to detect lies, even if it is widely used by law enforcement.