Whether the Bright-line Cut-off Rule and the Adversarial Expert Explanation of Adaptive Functioning Exacerbates Capital Juror Comprehension of the Intellectual Disability
54 Pages Posted: 16 Jun 2018
Date Written: May 30, 2018
This paper examines a sample of Capital Jury Project (CJP 1) cases with available trial transcripts in which jurors were presented with mitigating intellectual disability evidence and may have been confused by issues of proof, definitions, and extralegal factors. It tests the hypothesis that jurors’ receptivity to mitigating intellectual disability (ID) was limited by their difficulties with the adversarial mental proof and clinical definitions needed to establish it. Further the juror decision-making may have been obscured by distractions from extralegal factors, unrelated to the evidence like premature decision-making and heuristic shortcuts, pro-death bias, and racial prejudice. It also examines whether the bright line cut-off rule, followed in some sample states prior to the Supreme Court decision in Hall v. Florida (2014), exacerbated jurors’ understanding of the disability, and encouraged popular stereotypes and misconceptions about intellectual disability. In Kentucky, a state with the bright line cut-off rule, at the time these cases were decided, jurors were confused about a range of IQ scores and intellectual declines during developmental years. “IQ was perhaps not above what we consider a moron? I think they were contending that he had an IQ of 70 or 76 or so, had been tested as high as the 80s I recall.” (CJP KY death case #531, juror #725). Even in non-bright line sample States like South Carolina, with no ID exemption at the time, jurors misunderstood the range of numerical IQ evidence. The study concludes that juror assessment of intellectual disability (ID) is variable. Some jurors view ID as a more “organic” sympathetic disorder than other mental disorders, and they seem to understand it in practical, lay terms. Yet, capital juror decision making is marred by extra-legal factors that impair consideration of the mitigating evidence. The study concludes that juror misunderstanding regarding mitigating evidence has stubbornly persisted throughout the history of the Capital Jury Project and arises from shortcomings in human cognition which impede jurors’ moral consideration of intellectual disability evidence. In light of these flaws, it may be impossible to avoid the unacceptable risk that persons with intellectual disability will be executed. This study suggests that mildly intellectually disabled persons were indeed executed because jurors misunderstood the ID evidence and were persuaded by extralegal racial biases and premature decision making.
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