The Brain of a Liar
We all lie once a day or so, according to most studies. But usually we tell little lies, like "your new haircut looks great!" And most of us can control when we lie or what we lie about. But some people lie repeatedly and compulsively, about things both big and small.In 2005, a study published in The British Journal of Psychiatry provided the first evidence of structural differences in the brains of people with a history of persistent lying. The study was led by Yaling Yang, a doctoral student in psychology at the University of Southern California, and Adrian Raine, an expert on antisocial disorders who is now at University of Pennsylvania.They expected to see some kind of deficit in the brains of these liars, Yang says. But surprisingly, the liars in their study actually had a surplus - specifically, they had more connections in the part of their brains responsible for complex thinking. Radio Lab: Into the Brain of a Liar : NPR
The label "pathological liar" gets used in a variety of ways, and there's no standard psychological definition or test to measure if someone is a pathological liar. So Yang and her team chose to focus their study on people who have a history of repeated lying and seem not to be able to control their lying (hereafter called simply, "liars"). The researchers began by gathering volunteers from temporary employment agencies in the Los Angeles area. The idea was that liars would be over-represented at these agencies; a history of repeated lying would likely make it hard to keep a steady job.Then they ran 108 volunteers through extensive interviews and a battery of tests that measure patterns of deception. In the end, the team found 12 people who showed strong evidence of repeated and compulsive lying. For control groups, they identified 16 people who had antisocial tendencies but no history of lying and 21 people with no history of either lying or antisocial behavior.