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. Typically, people are 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 significantly better at it. There are a number of reasons as to this — the average person also does not expect others to lie to them and instinctively believes others are being truthful. 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.