Michael Benson

“Murderers with severe personality disorders, police had learned, sometimes could fool a lie detector because they lacked shame and guilt, and didn’t feel the normal stress when lying.”

“Vanderbilt University scientists had discovered chemically testable differences between psychopaths and others. One was the variance in levels of dopamine, a naturally produced chemical that contributed to a person’s motivation and pleasure. Those scientists concluded that the elevated level of dopamine was not an additional symptom to the personality abnormalities already known, but rather responsible for the personality changes.”