'The Psychopath Whisperer' by Kent A. Kiehl - The Boston Globe

: Kiehl’s research highlights that psychopathy is primarily a biological condition rather than just a social one. Psychopaths show significantly reduced gray matter density (5–10% less) in the paralimbic system , a network responsible for emotion, self-control, and moral decision-making.

: While they make up less than 1% of the population, psychopaths are responsible for a disproportionate amount of violent crime.