Bio-behavioral scientific evidence alters judges' sentencing decision-making: A quantitative analysis

The present study surveyed judges to examine how they consider and apply scientific information during sentencing determinations. Judges in criminal courts are increasingly asked to assess and make decisions based on evidence surrounding psychiatric disorders, with unclear results on sentencing outcomes. We qualitatively interviewed 34 judges who have presided over criminal cases in 16 different states and also administered vignette surveys during the interviews. We asked them to make sentencing decisions for hypothetical defendants in cases presenting evidence of either no psychiatric disorder, an organic brain disorder, or past trauma, as well as to rate the importance of different goals of sentencing for each case. Results indicated that the case presenting no evidence of a mental health condition received significantly more severe sentences as compared to either psychiatric condition. Judges' ratings of sentencing goals showed that the importance of retribution was a significant mediator of this relationship. Trauma was not deemed to be as mitigating as an organic brain disorder. These results provide unique insights into how judges assess cases and consider sentencing outcomes when presented with scientific information to explicate defendants' behavior. We propose ways forward that may help better integrate scientific understandings of behavior into criminal justice decision-making.