What works:
* Use open questions.
* Employ the element of surprise.
* Watch for small, verifiable details.
* Observe changes in confidence.<p>What people think works (but doesn't):
* Watch for certain body language
* Watch for certain eye movements<p>Just how badly does the old way work: "According to one study, just 50 out of 20,000 people managed to make a correct judgement with more than 80% accuracy. "