There are many ways in which a person’s body language can give you clues as to whether or not they are lying. Research has shown that people lie every four minutes of every day, and they may not even be aware that they are doing it. People who are lying often avoid eye contact, have a stiff facial expression, and exhibit closed off body language. They often try to distract the people they are speaking with, and may add too many details to their stories. Members of police departments and security experts use these clues to catch out criminals during interrogation.
One of the biggest signs that a person is telling lies is that he avoids eye contact during conversation. He may also touch his face continuously, very often covering his mouth with his hand. Touching or scratching the nose is also said to be a sign of distraction to cover up falsehoods. A person who is not telling the truth may be trying to make you focus on his actions rather than his words.
When a person tells lies, his physical expression is often very stiff and limited. If he is smiling as he speaks, only the mouth will move. A real smile involuntarily causes movement of the mouth, eyes, forehead, cheeks, and jaw.
The liar's hand, leg and arm movements are toward his own body; he takes up little space. The person’s body language is closed off. Liars do not look relaxed, even though they may be trying to give the impression that they are.
When a person lies, he has a variety of ways to distract you from the untrue statement. Liars may move around the room and place objects between you and them, such as a book or coffee cup. They will feel uncomfortable facing and looking directly at you when talking and may turn their head and body away. An innocent person will typically go on the offensive, while a guilty person will get defensive.
When explaining something, a liar may put into the conversation more detail than is necessary. He will usually be uncomfortable with pauses or silences. The person may speak softly or in garbled words. A very accomplished liar is able to speak directly and with confidence, however; salespeople are great at this technique.
If you suspect someone of lying, change the topic of conversation abruptly. The liar will willingly change topics with you and become more relaxed. A person who is telling the truth will typically become confused by this sudden change. Another sign of someone telling a lie is yawning — the person may try and look as relaxed as possible, and yawing and stretching are ways of achieving this.