• Psychopath: a person with a collection of interpersonal, affective and behavioural characteristics
including Interpersonal,Affective, Lifestyle andAntisocial deficits (manipulation, lack of remorse
or empathy, impulsivity and antisocial behaviours). These do not necessarily have to be criminals
– can be politicians, judges, etc and they may not even be committing any crimes.
• Base Rate: indication of the prevalence of a specific problem (psychopathy) within a specific
population (serial killers):
• 90% of serial killers are psychopathic (study: overestimate because he applied the tools to people
described in the media – proxy methodology).
• 1% of the general population are psychopaths (reliable estimate).
• 10-25% of the prison population are psychopaths.
• 44% of cop killers are psychopaths.
• 20% of male prisoners score above 30 (mean=22).
• 14% of female prisoners score above 30 (mean=19).
• Antisocial Personality Disorder (APD): (suffers from the lifestyle deficits) characterized by a
history of behaviour in which the rights of others are violated; they have demonstrated conduct
disorder by age 15 and display at least 3 of the following symptoms after 15:
• Repeat criminal acts;
• Impulsivity ;
• Reckless behaviours;
• Irresponsibility, and
• Lack of remorse.
• APD places more emphasis on antisocial behaviours than the PCL-R. Nearly all psychopathic
offenders meet the criteria forAPD but most offenders diagnosed withAPD are not
psychopaths. 60-80% of prisoners haveAPD.
• There are a few:
• Experience Impressions “In my clinical opinion”: based on their experience, training, case-by-
Though used, it’s frowned upon mostly because clinicians are inaccurate.
• Self-Report Inventories: MMPI, MCI, PPI.
Psychopaths can lie on self-report inventories so they’re not great.
• Informant Rating:ASPD. Where you get information about the person via other sources.
(Resolves the self-report problems).
• Structured Clinical: DSM-IV (equated to antisocial personality disorder, though psychopathy and
APD are different), PCL-R, PCL:YV (youth version).
• 2.1 PCL-R: Psychopathy-Checklist Revised
• PCL-R: the most popular method of assessing psychopathy in adults (Dr. Hare); the assessment
instrument is as follows...
• 20 items scored using a semi-structured interview and a review of file information to assess the
following three features:
• Interpersonal Features: glib/superficially charming, grandiose/inflated self-worth, manipulative. • Affective Features: shallow emotions, lack of guilty, callous.
• Behavioural (Lifestyle) Features: impulsivity, antisocial acts, poor anger control, criminal
• 3-point scale to measure psychopaths (2, scoring over 30 to 40), mixed – most criminals (1,
scoring between 20 and 30) and non-psychopaths (0, scoring between 0 and 20).
• 3. Psychopaths... (and why it’s important)
• 3.1And Violence
• Motives for Murder study: examining the relationship between psychopathy and how murders are
committed by dividing them into Reactive (unplanned, crimes of passion, extreme provocation)
and Instrumental (planned, settle a score).
• Results: of the people exhibiting Low PCL-R scores, Reactive murders were more likely; of the
people exhibiting High PCL-R scores, Instrumental murders are more likely.
• Re-offender study: retrospective assessment of male offenders; they examined the release
decision without knowing what the PCL-R score; they looked at parole releases and mandatory
supervision (statutory – after serving ⅔ of sentence) releases.
• Results: people re-offend as PCL-R score increases; statutory releases increase the likelihood of
• Juvenile Death Penalty study: hypothesis – if the person is labelled a psychopath, how does it
affect the jury? Two cases