Assessing psychopathy in the UK: concerns about cross-cultural generalisability

Background The diagnosis of psychopathy is important for violence risk assessment. Aims To investigate whether the syndromal structure of psychopathy, as measured by the Psychopathy Checklist - Revised (PCL-R), is the same in the UK and North America, and whether this measure yields scores that are equivalent in these two regions. Method Confirmatory factor analytic and item response theory methods were applied to large samples of PCL-R ratings Results The syndromal structure of psychopathy was invariant across cultures, three distinct factors underpinning the superordinate syndrome of psychopathy. However, PCL-R scores were not equivalent across cultures: the same level of psychopathy was associated with lower PCL-R scores in the UK. Items that reflected affective symptoms had the highest cross-cultural stability. Conclusions Scores on the PCL-R obtained in the UK are not directly comparable with those obtained in North America. Care must be exercised when the PCL-R is used to make important clinical decisions in the UK. Declaration of interest None.