Date Available


Year of Publication


Document Type



Arts and Sciences



First Advisor

David T. R. Berry


The 2002 Supreme Court decision (Atkins vs. Virginia, 536 U. S. 304), prohibiting the execution of mentally retarded persons, may potentially increase malingering of mental retardation (MR). There is limited research addressing the detection of feigned MR. The present study compared results from tests of intelligence, adaptive functioning, legal/courtroom knowledge, and psychiatric and neurocognitive feigning to determine how effectively these instruments discriminate between MR participants and community volunteers asked to either approach the test honestly (CVH group) or feign, or malinger, MR (CVM group). CVMs suppressed their IQ scores sufficiently to appear MR. CVMs overestimated deficits on individuals with genuine MR on tests of adaptive functioning and courtroom knowledge. Psychiatric feigning instruments did not discriminate between MR and CVM groups. Neurocognitive feigning instruments discriminated between groups, however specificity and Positive Predictive Power were unacceptably low. Revising cutting scores to hold specificity at .95 improved PPP significantly, suggesting the potential utility of these instruments to detect feigned mental retardation. Results from this study suggest that applying published decision rules to MR populations on tests commonly used in forensic neuropsychological evaluations will likely result in a high rate of false positive errors. Given the high stakes associated with classification errors in capital cases involving MR defendants, alternative cutting scores appropriate for this population should be determined.