The Art of Deception

Do tiny changes of facial expression show whether someone is telling lies? A Forty years ago, the research psychologist Dr. Paul Ekman was addressing a group of young psychiatrists in training when he was asked a question, the answer to which has kept him busy ever since. Suppose the group wanted to know: a particular patient swears they are telling the truth. They look and sound sincere. So here is the question: is there any way you can be sure they are telling the truth? Ekman did no...