Psychopaths are a rare breed. They makeup one percent of the general population and are harder to spot than a needle in a haystack. Outwardly, psychopaths can appear charming and normal. Yet their lack of conscience and empathy makes them wolves in sheep’s clothing. In October 2005, neuroscientist James Fallon was studying serial killers’ brain scans. He was looking for patterns in the brain that signify if a person has psychopathic tendencies or not.