Biological Evidence Regarding Psychopathy Does Not Affect Mock Jury Sentencing

Research on the biological factors influencing criminal behavior is increasingly being introduced into court, necessitating research on how such evidence is perceived and influences decision makers. Research on how this evidence influences sentencing recommendations is inconclusive. In this study, we focus on biological evidence related to psychopathy, a construct commonly associated with criminal behavior. Approximately 800 community members were presented with a case vignette detailing an individual who is described as having a high level of psychopathic traits. Participants received either psychological information about psychopathy (i.e., no biological evidence), evidence the defendant had genetic risk factors for psychopathy, or written neuroimaging evidence the defendant had brain deficits associated with psychopathy. Participants then recommended a sentence. Overall, recommended sentence lengths did not differ between evidence conditions. These findings add to a growing body of research suggesting that biological evidence may not have as much of an influence on jurors as previously thought.