Emily V. Shaw (University of California, Irvine, School of Social Sciences, Department of Psychology and Social Behavior, Students), Nicholas Scurich (University of California, Irvine), & David L. Faigman (University of California Hastings College of the Law) have posted Intellectual Disability, The Death Penalty, and Jurors (Jurimetrics, Vol. 58, 2018, forthcoming) on SSRN. Here is the abstract:
In Atkins v. Virginia (2002), the United States Supreme Court held that intellectually disabled defendants cannot be sentenced to death; but since then, the Court has continued to grapple with how intellectual disability should be legally defined. Typ-ically, however, it is jurors who determine whether a defendant is intellectually disabled and therefore categorically ineligible for the death penalty. Very little is known empiri-cally about how jurors reason about and make these decisions. This Article presents the results of a novel experiment in which venire jurors participated in an intellectual disa-bility hearing and a capital sentencing hearing. The diagnosis of a court-appointed expert was experimentally manipulated (defendant is or is not intellectually disabled), as was the provision of information about the crime (present or absent). Jurors were consider-ably more likely to find the defendant not disabled when the expert opined that the de-fendant was not disabled. They were also more likely to find the defendant not disabled when they learned about the details of the crime. Similarly, jurors were more likely to sentence the defendant to death after learning about the details of the crime, which in-creased perceptions of both the defendant’s blameworthiness and his mental ability. These findings highlight the reality that jurors’ assessments of intellectual disability are influenced by crime information, contrary to pronouncements made by the United States Supreme Court, and they support the use of bifurcated disability proceedings, as some states have recently adopted.