Investigating Presumed Deficits in Atkins v. Virginia: An Evaluation of Specific Functional Limitations

In the past ten years, two United States Supreme Court (USSC) decisions have served to narrow eligibility for capital punishment. Atkins v. Virginia (2002) excluded individuals with intellectual disability (previously mental retardation) and Roper v. Simmons (2005) excluded juveniles. The Court concluded in both cases that individuals in each category were less culpable due to a number of social impairments: communication, judgment, impulsivity, and suggestibility. Individuals with serious mental illness often possess such deficits but are not categorically excluded from capital punishment. This study sought to demonstrate the problematic nature of the Atkins decision with regard to the use of categorical exclusion from capital punishment. Those variables, as identified by the USSC as leading to decreased culpability for a population of individuals with intellectual disability or adolescents, are likely not limited to these groups. Three groups with functionally distinct capabilities were compared. These groups included individuals with intellectual disability, serious mental illness, and college students. These groups were compared on measures of expressive and receptive communication, logic reasoning, suggestibility, and impulse control. These three groups did not significantly differ in regard to each of the dependent measures, indicating the criteria justifying the Atkins decision has considerable overlap with other populations and does not solely apply to those with intellectual disability. Although not excluded from capital punishment, individuals with serious mental illness display similar deficits that exempt groups do