Along with hair color and eye color, some scientists believe that it could be possible to inherit a genetic predisposition to lie. A study conducted at the University of Southern California found that chronic liars had 22 percent more white matter in the prefrontal cortex of their brains and 14.2 percent less grey matter than generally honest people. Think of gray matter, or neurons, as the cells that do the thinking, and white matter as the cells that connect them. The lack of grey matter, which scientists believe controls moral behavior, is what they think may predispose an individual to lie, while the increased white matter makes it easier for them to do it. Read the full report in the print version of the October 2005 "British Journal of Psychiatry" (abstract available online).
Related: Nature vs. Nurture: Are We Really Born That Way?