Study finds biological cause for some kinds of lies

A preschooler tells her teacher that her parents are dead -- one of the earliest falsehoods of a pathological liar.

 Through the years, the girl's lies have been so profound, so unrelenting, that she has never been able to keep a friend. 



 Along the way, the young woman, now 19, and who asked not to be identified, pretended to have stomach cancer, countless pregnancies and an abusive boyfriend. Again, all lies. Now, scientists at the University of Southern California in Los Angeles may have provided a biological explanation for this kind of lying. 



 Yaling Yang and colleagues have identified structural changes in the prefrontal regions of the brain in pathological liars. Liars showed a 22 percent increase in the white matter in the brain and a 41 percent reduction in the ratio between gray and white matter. Scientists compared brain scans of people with a history of lying to those of normal people and to those with anti-social personality disorders. 



 Other scientists have used brain scans to measure differences in the chemical activity of the brain when people lie, but this is the first evidence that the brains of liars are anatomically different. 



 White matter contains the support cells that allow the neurons in the gray matter to perform complex cognitive tasks. 



 The researchers tested a dozen people with a history of lying, 16 with no signs of pathological lying, but who suffered from anti-social personality disorder, and 21 normal volunteers. All were between 21 and 45 years old. The findings were published recently in the British Journal of Psychiatry. 



 Adrian Raine, a co-author of the study, reported earlier that men with anti-social personality disorder have an 11 percent reduction in the gray matter in the front of the brain. 



 Raine and his colleagues said the new results implicate the prefrontal cortical white matter ``as an important (but not sole) component in the neural circuitry underlying lying, and provide an initial neurobiological correlate of a deceitful personality.'' 



 The scientists speculate that the increased white matter in the prefrontal cortex may leave a person more vulnerable to lying. This idea is derived from what scientists know about children, who are not good at lying. As the white matter expands with age, lying increases, so that by ages 10 to 12, children become better at lying. 



 ``It is so easy to treat these individuals with disdain,'' said Dr. Marc Feldman, a clinical professor of psychiatry at the University of Alabama at Tuscaloosa. ``So many pathological liars describe their lying as compulsive or akin to an addiction. I now conceptualize it as an illness rather than simple misbehavior.'' 



 Feldman called the 19-year-old woman, whom he met in an online counseling group, a classic case of a pathological liar. 



 ``I know that I do this to get attention,'' she said during a recent phone interview. A year ago, her childhood obsession with ``being pregnant'' came true. Throughout her pregnancy, she was obsessed with thoughts about her unborn child and promised that her lies would stop with his birth. 



 When she told an Internet support group that her 7-month-old son had leukemia, she realized it ``was the straw that broke the camel's back. I knew I needed help.'' 



 Anti-depressants worked for three months. She is now trying to find a therapist. ``Eventually, you would think I would just learn. But I don't,'' she said.