Describing, diagnosing, and naming psychopathy: how do youth psychopathy labels influence jurors?

Previous studies have reached opposing conclusions regarding how psychopathy assessment influences the court's response to a juvenile defendant. This study sought to clarify the apparent discrepancies across studies by distinguishing among three key variables: history of antisocial behavior (substantial versus minimal), psychopathic personality traits (present versus absent), and diagnostic label (no diagnosis, conduct disorder, psychopathy, or "is a psychopath"). We systematically manipulated these variables in vignettes describing expert testimony, and then distributed these vignettes to 891 jury-pool members. Descriptions of the antisocial behavior and psychopathic personality traits underlying diagnoses tended to have stronger effects than did the diagnostic labels (i.e. psychopathy or conduct disorder). However, labeling juvenile defendants with the colloquial term "psychopath" led jurors to believe that they posed greater risk for future crime and deserved greater punishment compared with juveniles described as meeting diagnostic criteria for psychopathy or conduct disorder. Results should influence the language forensic evaluators use in practice. Results should also inform research that investigates diagnostic labeling effects.