There are nine basic signs that liars exhibit. Not all of these signs may be witnessed, and not all mean that they are lying. They are just guidelines as to the body language that many liars display.
1) A change in the tone and pitch of the person's voice.
2) An increased or decreased rate of speech.
3) Stumbling over sentences, stopping to think during a sentence, increased use of 'um' and 'uh'.
4) A change in the amount of eye contact. Normal people make eye contact between one-fourth and one-half of the time that they are talking to you. Liars tend to make less eye contact.
5) Turning their shoulders away.
6) Looking very far to the left, right, up or down more than twice.
7) Touching their face or scratching their head.
8) Involuntary moving, jiggling, scratching, or other fidgeting of the legs or feat.
9) Crossing of the arms and/or legs.
