Psychopathy is a spectrum disorder and can be diagnosed using the 20-item Hare Psychopathy Checklist, which features traits such as lack of empathy, pathological lying, and impulsivity, each scored on a three-point scale based on whether the item does not apply (0), applies to a certain extent (1), or fully applies (2) to the individual. The bar for clinical psychopathy is a score of 30 or higher; serial killer Ted Bundy scored 39.
The checklist was developed in the 1970s by the Canadian researcher Robert Hare. A true assessment should be conducted by a mental health professional.
The revised version of the checklist includes the following characteristics:
Glibness/superficial charm
Grandiose sense of self-worth
Need for stimulation/proneness to boredom
Pathological lying
Conning/manipulative
Lack of remorse or guilt
Shallow affect (i.e., reduced emotional responses)
Callous/lack of empathy
Parasitic lifestyle
Poor behavioral controls
Promiscuous sexual behavior
Early behavioral problems
Lack of realistic, long-term goals
Impulsivity
Irresponsibility
Failure to accept responsibility for one's own actions
Many short-term marital relationships
Juvenile delinquency
Revocation of conditional release (from prison)
Criminal versatility (i.e., commits diverse types of crimes)
