Find Out the Truth - Study the Liar's Body Language

You watch movies where CIA agents are talking to the suspect, and one CIA agent calmly states that the suspect is lying, and that he ought to tell the truth. The suspects eyes widen, shocked, perhaps, and spills his guts. What? you may think to yourself. How did he know?

It's a seemingly superhuman ability. Maybe they can see right through you. Maybe it's the result of some secret government training that is being hidden from the public eye. While I can't say whether or not CIA agents receive top-secret-stolen-Soviet-technology-Cold-War-era training (After all, I'm not a CIA agent. Or am I?), I can definitely tell you that the general public can be taught to discern between truthtellers and liars fairly easily.

You'll want to watch their body language. The old addage that the eyes always tell the truth holds true to the rest of the body as well. Your body will always betray you somehow.

A liar will avoid eye contact. If eye contact is made, the liar will be quick to look away.

The liar's facial expressions will be timed oddly, and will usually not be coordinated with what they are saying. They may say something, and then the facial expression comes after it. In most cases of truthtelling, the facial expression comes first or at the same time the spoken words.

Also, the liar's facial expressions will be shallow; fake smiles will only engage the muscles around the mouth, and none of the muscles aroung the cheeks, eyes, or nose.

As much or more than as with their body language, you will want to pay attention to their words.

A liar will usually avoid referring to themselves as "I".

A liar will probably use your own words directly when responding to the question. For example, when the liar is asked, "Did you take my stapler?" the liar might respond, "Take your stapler? No," or something to that effect.

Excessive and extraneous details are given which may not serve to strengthen the liar's argument, but, instead, act as "filler", detracting from the topic. The liar's speech will be either much slower or much faster than normal, and will usually be monotone, even when expressing emotion.