Rater differences in psychopathy measure scoring and predictive validity.

Area of Science:

• Forensic Psychology
• Psychometrics

Background:

• Field studies indicate variability in forensic evaluators' psychopathy scoring, particularly for sexual offenders.
• The impact of evaluator scoring differences on the predictive validity of psychopathy measures remains under-examined.

Purpose of the Study:

• To investigate rater differences in psychopathy measure scoring within a rigorous research context.
• To examine the predictive effects associated with evaluator scoring variations in psychopathy assessments.

Main Methods:

• Utilized data from the MacArthur Violence Risk Assessment Study.
• Analyzed scoring variance in the Psychopathy Checklist: Screening Version (PCL:SV) attributable to trained raters.
• Assessed the association between PCL:SV scores (including Facet 4) and future violence, considering evaluator scoring tendencies.

Main Results:

• Rater variance was higher for PCL:SV Part 1 (14%) than Part 2 (4%).
• The link between Facet 4 scores and future violence was stronger for evaluators with higher and more variable Facet 4 scores.
• Mean scoring differences influenced risk interpretation, altering the threshold for high-risk classification.

Conclusions:

• Limited evidence suggests an association between PCL:SV scoring tendencies and predictive validity.
• Evaluator scoring tendencies have implications for psychopathy score interpretation and risk assessment.
• Forensic evaluators should be mindful of their scoring patterns and their consistency with normative data.