Derren Brown - Someone's lying - How's it done?

Derren Brown - Someone's lying - How's it done?:

"Classic signs of lying include bringing the hand up to the face – for example, to stroke the chin or touching the nose. The speaker makes these movements almost as if he wants to 'hide' the words coming out of his mouth.

You should also look out for eye movements. Generally, if people are thinking of visual information to answer a question, their eyes will move up: this is how they retrieve mental pictures. They do this unconsciously, but they will also tend to do it reliably. Once you know that, you can look for the instance when they don't look up in the same way, or when they look up but perhaps to the other side, or when they maintain eye contact with you when they would normally do otherwise.

This last is an interesting point. Most people imagine that we maintain eye contact when we tell the truth and break it when we lie. Not so. The majority of people will maintain eye contact when lying, because they don't need to retrieve information from their minds and, therefore, don't need to move their eyes. At another level, they are eager to appear sincere, and so consciously decide to keep looking at you.

But the point is not that such-and-such behaviour means a lie. The secret is to watch people closely and, keeping your wits about you, follow their mental processes in your own mind. Look for their patterns and see where they fall down. Watch for an answer that breaks the rules – the odd one out will be the lie."