Despite the fact that the condition called “pathological liar” has been on the books for 100 years, very little research has been done on it. Pathologies are a defect in the mind or body, such as cancer. There is no proof that pathological liars are, in fact, suffering from pathologies. There are other mental and emotional disorders that have lying as a symptom, but no disease or disorder is shown to be the “pathological” part of pathological liars. There are also studies showing that liars tend to learn this behavior, rather than having something wrong in their head.
Read the full article here: A Pathological Liar Is Made, Not Born: When Telling The Truth Is Nearly Impossible