Psychopathy is among the most difficult disorders to spot. The psychopath can appear normal, even charming. Underneath, he lacks conscience and empathy, making him manipulative, volatile and often (but by no means always) criminal. She is an object of popular fascination and clinical anguish: adult psychopathy is largely impervious to treatment, though programs are in place to treat callous, unemotional youth in hopes of preventing them from maturing into psychopaths.

Psychopathy is a spectrum disorder and can be diagnosed only using the 20-item Hare Psychopathy Checklist. (The bar for clinical psychopathy is a score of 30 or more). Brain anatomy, genetics, and a person’s environment may all contribute to the development of psychopathic traits.

The terms “psychopath” and “sociopath” are often used interchangeably, but in correct parlance a “sociopath” refers to a person with antisocial tendencies that are ascribed to social or environmental factors, whereas psychopathic traits are more innate, though a chaotic or violent upbringing may tip the scales for those already predisposed to behave psychopathically. Both constructs are most closely represented in the Diagnostic and Statistical Manual of Mental Disorders (DSM) as Antisocial Personality Disorder.