How To Tell if Someone is Lying

There are a variety of ways to know if someone is lying. Even if you don't have a lie detector/polygraph on hand, there are often indications in a person's body language, facial expression, tone of voice and choice of words that can indicate if they are telling the truth or not.

Body language can be a dead giveaway. If a person has minimal body movement, and is very stiff, it may mean they are lying. There will be minimal movement even when they are talking. They are also less likely to make eye contact with you. If their hands touch their face, throat or mouth it may also be an indication that they're lying.

The display of emotion is delayed. Maybe it will take a few seconds to laugh at something funny. And then it goes on for longer than normal, and stops abruptly. The timing is also off between emotional gestures and expression of words. For example, if someone says "that's great news" but only smiles after saying it that's a sign that they're lying. Also if the gestures don't match the words, for example frowning while saying something positive. If facial expressions are just in the mouth rather than the entire face it can also be a sign that they are faking the emotion.

People who are guilty tend to be defensive. A liar may turn his or her head or body away from an accuser. The liar may even place objects, like a coffee cup between them and you.

A liar will often repeat the words in a question you ask. For example, if you ask "were you with watching the game with "x" last night?" they may answer "yes, I was watching the game with "x" last night". If they say "I wasn't with her" it's more likely to be honest than if they say "I was not with her". Sometimes liars will avoid answering a question directly so as not to lie. Instead they will imply an answer. A guilty person may be very talkative and will often give more information than necessary and is uncomfortable with silence. A liar will often skip over pronouns like "he", "she" or "which". When telling the truth a person will tend to emphasize these words more.

If you think someone is lying about a certain subject then quickly change the subject. The liar will go along with eagerly and become more relaxed. An innocent person may want to go back to the previous subject. Sometimes a liar will also use humor or sarcasm to avoid a subject.