Nonverbal clues can be revealing because liars don’t rehearse gestures, just words. They freeze their upper body, oftentimes look down, lower their voice, slow their breathing and blink rate, slump, and then exhibit relief when the interview is over. Interrogators will often end an interview prematurely just to look for that relief—that shift in posture and relaxation. Pay attention to science and not myths: We think liars won’t look you in the eyes, but it turns out an honest person will only look you in the eyes about 60 percent of the time.
But be careful:
According to a 2002 study conducted by the University of Massachusetts, 60% of adults can’t have a ten minute conversation without lying at least once. But even that number makes it sound better than it really is; those people in the study who did lie actually told an average of 3 lies during their brief chat. And I know you’re sitting there right now insisting you would be part of the 40% that didn’t lie. That’s what the liars in the study thought, too. When they watched the taped conversations back, they were shocked at how many fibs they had told.