Psychopathy and moral reasoning: Comparison of two classifications

Forty Special Hospital patients were assessed using two different measures of psychopathic personality—the Special Hospitals Assessment of Personality and Socialization (SHAPS) and the Psychopathy Check List-Revised (PCL-R). Subjects completed the Defining Issues Test (DIT), an assessment of moral reasoning ability. There was little agreement on classification between the two measures of psychopathy, or between either of the measures and Mental Health Act classification of psychopathic disorder. A negative correlation was found between PCL-R scores and IQ scores. Scores on the PCL-R were negatively related to moral reasoning, but the relationship did not hold when IQ was partialled out. A modest negative relationship was observed between moral reasoning and the SHAPS factor of antisocial aggression.