Psychiatrists see lying as pathological when it is so persistent as to be destructive to the liar’s life, or to those to whom he lies.
The most blatant lying is found in the condition called ‘‘pseudologia fantastica,’‘ in which a person concocts a stream of fictitious tales about his past, many with a small kernel of truth, all self-aggrandizing.
”Pathological liars seem utterly sincere about their lies, but if confronted with facts to the contrary, will often just as sincerely reverse their story,” Dr. King said. ”Their stories have a believable consistency, but they just do not seem able to monitor whether they are telling the truth or not.”
Research suggests that this most extreme form of lying is associated with a specific neurological pattern: a minor memory deficit combined with impairment in the frontal lobes, which critically evaluate information, Dr. King said. In such cases, the person suffers from the inability to assess the accuracy of what he says, and so can tell lies as though they were true.