The following 2002 literature review attempted to answer the above (and more) questions. Whether the findings of this 7 year old survey hold true today is not known. If I can find relevant information I will post it.
- Cunningham, M. D. and Vigen, M. P. (2002). Death Row Inmate Characteristics, Adjustment, and Confinement: A Critical Review of the Literature. Behavioral Sciences and the Law, 20, 191–210 (click here to view).
[note: Italics are direct quotes. Underline is emphasis added by the blogmaster]
This article reviews and summarizes research on death row inmates. The contributions and weaknesses of death row demographic data, clinical studies, and research based on institutional records are critiqued. Our analysis shows that death row inmates are overwhelmingly male and disproportionately Southern. Racial representation remains controversial. Frequently death row inmates are intellectually limited and academically deficient. Histories of significant neurological insult are common, as are developmental histories of trauma, family disruption, and substance abuse. Rates of psychological disorder among death row inmates are high, with conditions of confinement appearing to precipitate or aggravate these disorders. Contrary to expectation, the extant research indicates that the majority of death row inmates do not exhibit violence in prison even in more open institutional settings. These findings have implications for forensic mental health sentencing evaluations, competent attorney representation, provision of mental health services, racial disparity in death sentences, death row security and confinement policies, and moral culpability considerations. Future research directions on death row populations are suggested.
According to Cunningham and Vigen (hereafter referred to as the "authors"), the research "literature on death row inmates has not been comprehensively summarized and reviewed. This article attempts to fill that void by reviewing the extant literature on the characteristics of death row inmates, their adjustment to prison, and their conditions of confinement."
The scope of coverage of this review article is impossible to summarize in a single blog post. More importantly, the focus of this blog is on the mental retardation/intellectual competence characteristics of this population. As thus, this post will only summarize the information in this survey article related to this focus. Other topics discussed (methodological review of prior research; woman, race, psychological disorders, neurological disorders, drug use, etc. issues) will not be covered (readers can view the original article for this information)
According to the authors:
- Eleven of the 13 clinical studies reported data on the intellectual capability of death row samples. Mean IQ scores were in the average to low average range, generally consistent with the intellectual capabilities of general prison population inmates (Panton, 1976). A significant minority of death row inmates, though, exhibited marked intellectual limitations. For example, 27% of the Mississippi death row sample investigated by Cunningham and Vigen (1999) had WAIS-R Verbal IQ scores below 74.
- Similarly, Frierson et al. (1998) reported that 28% of their death row sample obtained IQ scores in the borderline or mentally retarded classifications.
- National demographic data (Snell, 2001) indicate that 52.3% of death row inmates did not finish high school and 12.7% attended only to the eighth grade or less. Median formal education was 11th grade. These rates of educational attainment are similar to or only modestly lower than those observed in the general state prison population nationwide
- Clinical studies on death row inmates found a somewhat lower level of formal education, typically reporting a mean of ninth grade schooling.
While much of the research on death row inmates has limitations in specificity, sampling, methodology, and reporting, there are a number of recurrent findings. To summarize these, death row inmates are overwhelmingly male and disproportionately Southern. Over half of death row inmates are non-whites. A majority did not graduate from high school. Mean IQ scores of death row inmates are in the low average-to-average range, but a disturbingly large minority exhibits IQ scores in the borderline and mental retardation ranges. Functional literacy capabilities are well below what would be expected from the years of schooling attended. Whether these literacy deficits are the result of learning disabilities or other factors cannot be determined from the current data. There is also a significant incidence of neurological and neuropsychological abnormalities among death row inmates. Psychological disorders are quite frequent among death row inmates. The particularly adverse conditions of death row confinement in some jurisdictions appear to not only undermine efforts to adaptively cope, but also act to aggravate psychological symptoms. Current prison mental health interventions are insufficient.
Policy Implications (as per authors)
given the conclusions of the clinical studies, mental health experts performing forensic evaluations at capital sentencing should be attentive to the presence of neurological abnormalities, learning disabilities, psychiatric disorders, and traumatic developmental histories. These vulnerabilities were more frequently identified in studies that undertook broader and more time intensive evaluations. This speaks to the need for comprehensive examinations as well as sufficient interview duration for reasonable self-disclosure to occur. Adequate forensic evaluation at sentencing, therefore, requires particularly careful assessment of the vulnerabilities of this population, as well as knowledge of the current literature regarding the behavioral implications of these deficiencies and underlying adverse developmental factors.
the intellectual, literacy, and psychological deficits of most death row inmates render them incapable of responding to the demands of direct appeals or postconviction proceedings without the assistance and representation of qualified legal counsel
the significant percentage of racial minorities, and particularly African– Americans, on death row nationwide has varying interpretations—the most disturbing of these asserting that racial bias in the application of the death penalty, whether by race of offender or race of victim, is both a historical legacy and a continuing social policy problem.
the incidence of psychological symptoms and mental health problems among death row inmates calls for comprehensive mental health services. Effective treatment of psychological symptoms and disorders among death row inmates is not only humane, but likely to facilitate institutional management and reduce disciplinary misconduct.
it is disturbing that so many inmates on death row are so obviously damaged—developmentally, intellectually, educationally, neurologically, and psychologically. To the extent that the death penalty is intended to punish those murderers who are most morally culpable, there would seem to be some miscarriage of that intent when it is visited upon individuals who are manifestly damaged, deficient, or disturbed in their psychological development and functioning.
Technorati Tags: psychology, forensic psychology, neuropsychology, educational psychology, developmental, IQ, intelligence, IQ scores, death penalty, capital punishment, mental retardation, MR, Atkins cases, U. S. Supreme Court