Judging honesty by story telling.

Benedict Carey summarizes work on detecting lying, not by body language cues, but by what people say. People telling the truth tend to add 20 to 30 percent more external detail than do those who are lying. If you’re telling the truth, this mental reinstatement of contexts triggers more and more external details. Not so if you’ve got a concocted story and you’re sticking to it. “It’s the difference between a tree in full flower in the summer and a barren stick in winter."