The careful observer can notice clues indicating that someone is telling a lie. People give off these clues because:

Question

Quizplus · Accepted Answer

Nonverbal communication, including facial expressions and body language, is often involuntary and difficult to completely control, even for skilled liars. This can lead to unintentional cues that can indicate deception. Culture does play a role in some gestures associated with lying, but this is not the main reason for the clues. The idea that few people intend to lie is not entirely accurate, as lying can sometimes be intentional. There is also no evidence to support the claim that most criminals want to be caught.

The Careful Observer Can Notice Clues Indicating That Someone Is