Psychopathy is characterized above all by lack of empathy and other emotions. That lack enables psychopaths to be highly manipulative of others. Nevertheless, psychopathy is among the most difficult disorders to spot. Psychopaths can appear normal, even charming. Underneath, they lack any semblance of conscience. Their antisocial nature inclines them often (but by no means always) to criminality.
Psychopaths are objects of popular fascination and clinical anguish: Adult psychopathy is largely impervious to treatment, though programs exist to treat callous, unemotional youth in hopes of preventing them from maturing into psychopaths.
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 thought to be more innate, though a chaotic or violent upbringing may tip the scales for those already predisposed to meanness and remorselessness of psychopathy.
Both constructs are most closely represented in the Diagnostic and Statistical Manual of Mental Disorders (DSM) as Antisocial Personality Disorder. The DSM uses neither "psychopathy" nor "sociopathy," though these terms are widely used in clinical and common parlance.
Brain anatomy, genetics, and a person’s environment may all contribute to the development of psychopathic traits. For more on causes, symptoms and treatments of antisocial personality disorder, see our Diagnosis Dictionary.