The PCL-R is a clinical rating scale (rated by a psychologist or other professional) of 20 items. Each of the items in the PCL-R is scored on a three-point scale according to specific criteria through file information and a semi-structured interview. A value of 0 is assigned if the item does not apply, 1 if it applies somewhat, and 2 if it fully applies. In addition to lifestyle and criminal behavior the checklist assesses glib andsuperficial charm, grandiosity, need for stimulation, pathological lying, conning and manipulating, lack of remorse, callousness, poor behavioral controls, impulsivity, irresponsibility, failure to accept responsibility for one's own actions and so forth. The scores are used to predict risk for criminal re-offence and probability of rehabilitation.
The current edition of the PCL-R officially lists three factors (1.a, 1.b,, and 2.a), which summarize the 20 assessed areas via factor analysis. The previous edition of the PCL-R listed two factors. Factor 1 is labelled "selfish, callous and remorseless use of others". Factor 2 is labelled as "chronically unstable, antisocial and socially deviant lifestyle". There is a high risk of recidivism and currently small likelihood of rehabilitation for those who are labelled as having "psychopathy" on the basis of the PCL-R ratings in the manual for the test, although treatment research is ongoing.
PCL-R Factors 1a and 1b are correlated with narcissistic personality disorder and histrionic personality disorder. They are associated with extraversion and positive affect. Factor 1, the so-called core personality traits of psychopathy, may even be beneficial for the psychopath (in terms of nondeviant social functioning).
PCL-R Factors 2a and 2b are particularly strongly correlated to antisocial personality disorder and criminality and are associated with reactive anger, criminality, and impulsive violence. The target group for the PCL-R is convicted criminals. The quality of ratings may depend on how much background information is available and whether the person rated is honest and forthright.
Factor 1: Personality "Aggressive narcissism"
- Glibness/superficial charm
- Grandiose sense of self-worth
- Pathological lying
- Lack of remorse or guilt
- Shallow affect (genuine emotion is short-lived and egocentric)
- Callousness; lack of empathy
- Failure to accept responsibility for own actions
Factor 2: Case history "Socially deviant lifestyle".
- Need for stimulation/proneness to boredom
- Parasitic lifestyle
- Poor behavioral control
- Lack of realistic long-term goals
- Juvenile delinquency
- Early behavior problems
- Revocation of conditional release
Traits not correlated with either factor
- Promiscuous sexual behavior
- Many short-term marital relationships
- Criminal versatility
- Acquired behavioural sociopathy/sociological conditioning (Item 21: a newly identified trait i.e. a person relying on sociological strategies and tricks to deceive)
Early factor analysis of the PCL-R indicated it consisted of two factors. Factor 1 captures traits dealing with the interpersonal and affective deficits of psychopathy (e.g. shallow affect, superficial charm, manipulativeness, lack of empathy) whereas Factor 2 dealt with symptoms relating to antisocial behaviour (e.g. criminal versatility, impulsiveness, irresponsibility, poor behaviour controls, juvenile delinquency).
The two factors have been found by those following this theory to display different correlates. Factor 1 has been correlated with narcissistic personality disorder, low anxiety, low empathy, low stress reaction and low suicide risk but high scores on scales of achievement and social potency. In addition, the use of item response theory analysis of female offender PCL-R scores indicates factor 1 items are more important in measuring and generalizing the construct of psychopathy in women than factor 2 items.
In contrast, Factor 2 was found to be related to antisocial personality disorder, social deviance, sensation seeking, low socio-economic status and high risk of suicide. The two factors are nonetheless highly correlated and there are strong indications they do result from a single underlying disorder. However, research has failed to replicate the two-factor model in female samples.
Recent statistical analysis using confirmatory factor analysis by Cooke and Michie indicated a three-factor structure, with those items from factor 2 strictly relating to antisocial behaviour (criminal versatility, juvenile delinquency, revocation of conditional release, early behavioural problems and poor behavioural controls) removed from the final model. The remaining items are divided into three factors: Arrogant and Deceitful Interpersonal Style, Deficient Affective Experience and Impulsive and Irresponsible Behavioural Style.
In the most recent edition of the PCL-R, Hare adds a fourth antisocial behaviour factor, consisting of those Factor 2 items excluded in the previous model. Again, these models are presumed to be hierarchical with a single unified psychopathy disorder underlying the distinct but correlated factors.
The Cooke & Michie hierarchical ‘three’-factor model has severe statistical problems—i.e., it actually contains ten factors and results in impossible parameters (negative variances)—as well as conceptual problems. Hare and colleagues have published detailed critiques of the Cooke & Michie model. New evidence, across a range of samples and diverse measures, now supports a four-factor model of the psychopathy construct, which represents the Interpersonal, Affective, Lifestyle, and overt Antisocial features of the personality disorder.