The impact of mental health evidence on support for capital punishment: are defendants labeled psychopathic considered more deserving of death?


  • Portions of this research were completed while Dr Edens was a faculty member in the Department of Psychology at Sam Houston State University.


Controversy surrounds the use of the Hare Psychopathy Checklist—Revised (Hare, 1991, 2003) in capital murder cases, where it has been introduced to support prosecution claims that a defendant represents a “continuing threat to society”. Although widely presumed to have a prejudicial impact (e.g., American Psychological Association, 2004), little is known about how the lay public reacts to data derived from ostensibly stigmatizing assessment instruments such as the PCL-R. The present study examined the effect of psychopathy data on layperson attitudes by having 203 undergraduates review a capital murder case where the results of the defendant's psychological evaluation were experimentally manipulated. When expert testimony described the defendant as psychopathic, a much larger percentage of participants supported a death sentence (60%) than when testimony indicated that he was psychotic (30%) or not mentally disordered (38%). Interestingly, participant ratings of how psychopathic they perceived the defendant to be—regardless of the testimony condition to which they had been assigned—also predicted support for a death sentence. Given the limited probative value of the PCL-R in capital cases and the prejudicial nature of the effects noted in this study, we recommend that forensic examiners avoid using it in these trials. Copyright © 2005 John Wiley & Sons, Ltd.