Almost everyone lies occasionally, but for a small percentage of people, lying isn't something that they do every once in a while -- it's a way of life. Drew Curtis, PhD, of Angelo State University, and Christian L. Hart, PhD, of Texas Woman’s University, authors of a new book on pathological lying, talk about what drives “big liars” to lie, why they believe pathological lying should be classified as a mental health disorder, whether liars really are more prevalent in some professions, such as politics and sales, and how you can recognize lies and protect yourself from being duped. For transcripts, links and more information, please visit the Speaking of Psychology Homepage.