Another good reason to sleep uneasily at night. MORE
In fact, Dr. Robert Hare, the author of Without Conscience, estimates that there could be as many as 100,000 psychopaths in New York City alone--and at least 2 million in North America. Given that psychopaths--those without empathy for others who are typically con artists and users--have a higher rate of violent crime--it is very probable that my polygrapher friend would have numerous opportunites to encounter a psychopath in his work.
(Found on Dr. Helen Smith’s blog: drhelen.blogspot.com) If you’re in the mental health field she has a lot of interesting articles.