The Mask of Sanity: An Attempt to Clarify Some Issues About the So-Called Psychopathic Personality is a book written by American psychiatrist Hervey M. Cleckley, first published in 1941, describing Cleckley’s clinical interviews with patients in a locked institution. The text is considered to be a seminal work and the most influential clinical description of psychopathy in the twentieth century. The basic elements of psychopathy outlined by Cleckley are still relevant today. The title refers to the normal “mask” that conceals the mental disorder of the psychopathic person in Cleckley’s conceptualization.
Cleckley then summarizes the material and provides a ‘clinical profile’, describing 16 behavioral characteristics of a psychopath (reduced from 21 in the first edition): 
- Superficial charm and good intelligence
- Absence of delusions and other signs of irrational thinking
- Absence of nervousness or psychoneurotic manifestations
- Untruthfulness and insincerity
- Lack of remorse and shame
- Inadequately motivated antisocial behavior
- Poor judgment and failure to learn by experience
- Pathologic egocentricity and incapacity for love
- General poverty in major affective reactions
- Specific loss of insight
- Unresponsiveness in general interpersonal relations
- Fantastic and uninviting behavior with drink and sometimes without
- Suicide threats rarely carried out
- Sex life impersonal, trivial, and poorly integrated
- Failure to follow any life plan.
Some of the criteria have obvious psychodynamic implications, such as a lack of remorse, poor judgment, failure to learn from experience, pathological egocentricity, lack of capacity for love, a general poverty in major affective reactions, and lack of insight into his own condition. Starting in 1972, newer editions of the book reflected a closer alliance with Kernberg‘s (1984) borderline level of personality organization, specifically defining the structural criteria of the psychopath’s identity integration, defensive operations and reality testing.