Abstracted quotes from Salekin et al. (2010). Emphasis added by ICDP blogmaster.
- Before the ruling in Atkins v. Virginia (2002), there was a virtual absence of discussion of the possibility of feigned ID in forensic evaluations.
- In recent years, the question of whether the condition of ID can be feigned has been argued in the literature (Baroff, 2003; Ellis, 2003; Mossman, 2003; Stevens & Price, 2006), with empirical data demonstrating the limited utility of effort tests and other measures of cognitive malingering (for reviews see Dean, Victor, Boone, & Arnold, 2008; Graue et al., 2007; Salekin & Doane, 2009). Only one empirical study has been conducted on the ability to feign deficits in adaptive behavior (Doane & Salekin, 2009).
- One of the arguments against successful feigning of the disorder is that the diagnosis requires the presence of deficits in ID and adaptive behavior that were evident before the age of 18 years. It would follow then that a person who asserts a claim of ID in a criminal proceeding would have documentation of impaired cognitive and adaptive functioning before the age of 18 years (e.g., special education records; disability documents; prior psychological evaluations) and/or would be able to provide collateral sources to support this assertion. In short, those who challenge the idea that ID can be feigned in the criminal justice system base their belief on the notion that people do not feign this disorder during a time in which there is no incentive to do so.
- Research on the use of existing measures of malingering has produced disappointing results and overall has demonstrated that existing measures and methods, when used according to the current standards of practice, often misclassify people with bona fide ID as malingerers. The reader is directed to an article by Graue et al. (2007) in which the findings of prior research are detailed and the results are presented regarding malingering on tests of intelligence, malingered mental illness, and neurocognitive measures.
- In short, Graue and colleagues documented the questionable validity of existing measures of malingering when used with an ID population.
- Although additional research is needed regarding the ability to malinger ID successfully, the malingering of ID, no matter how poorly done, will be attempted in some criminal cases. The authors further believe that individuals who would attempt to feign ID are limited to those who have true scores that fall between one and two standard deviations below the mean on either or both prongs of the ID diagnostic criteria. Offenders who fall in the average range of cognitive ability and/or adaptive behavior would not have demonstrated the requisite level of deficits in adaptive behavior in the community to meet the criteria for the diagnosis (this would be true even if they successfully reduced their score on an IQ test). Nevertheless, in light of the possibility that a person can successfully feign the disorder, it has become important to find ways to evaluate this response style while maintaining a very low rate of false positives.