Beyond Atkins: how do the prongs perform during sentencing?
In Atkins v. Virginia (2002) the High Court categorically excluded individuals with intellectual disability (ID) from a punishment of death due to the limited judgment, poor reasoning, and reduced levels of impulse control inherent in the disability. This research explored the impact of the diagnostic prongs during sentencing for offenders found guilty of a capital crime and who failed to prove ID during an Atkins hearing. The current study used a mock jury deliberation paradigm with a large sample of undergraduate students divided into four-, five-, or six-person mock juries. Two of the three diagnostic prongs, limited intelligence and deficits in adaptive behavior, were manipulated with the goal of identifying how these deficits (or lack thereof) are interpreted independently, and in conjunction with, one another during capital mitigation. The results indicated that both IQ and AB deficits are considered mitigating by death-qualified mock jurors, and information about deficits in one or both of these areas was associated with a 1.8 times greater likelihood of a sentence of life without the possibility of parole relative to the condition in which neither IQ nor AB deficits were present. Consistent with the High Court’s ruling in Atkins v. Virginia (2002), participants who believed the hypothetical defendant had ID were significantly less likely to sentence him to death as opposed to life in prison without the possibility of parole. More broadly speaking, the current study also provided evidence that perceptions of mitigating factors mediate the relationship between individual attitudes and ultimate sentencing determinations, and perceptions of mitigating factors can be understood through the lens of attribution theory. Implications are discussed with a particular emphasis on how this information can be used in the courtroom. Recommendations for research are offered.