Dr. Bruce Frumkin presents a comprehensive overview of the strengths and weaknesses of intellectual assessment tools and offers a practical guide for forensic clinicians and attorneys faced with criminal cases involving mental retardation claims. Such a defense has implications for rulings regarding competency to stand trial and the extent to which a defendant can be found criminally responsible for an offense.
For starters, it is important to understand the meaning of “intelligence” and the way many assessment tools, such as IQ tests (i.e., WAIS-III, WIAS-III, MMPI-2, etc.) or adaptive behavior testing, can impact the findings of a clinician. Frumkin explores the definition of mental retardation and cautions that a low IQ score should never be deemed to be the cause of mental retardation. In addition, he offers that IQ scores and even behavioral assessment tools are often flawed, limited, outdated, and lack solid sample comparisons due to a lack of norms. For example, many behavior assessment tools ask for details that cannot be gathered if the defendant has been incarcerated for many years or the third party providing feedback has not had recent contact with the individual. Many assessment tools use checklists where answers can be easily distorted. The author argues that both performance and verbal measurements should be taken into consideration for best results (Frumkin, 2006).
Practice effects (familiarity with certain testing models over time) and also the Flynn effect (general/random IQ increases over time) are also discussed. According to Frumkin, many attorneys prefer older IQ tests to be used when a mental retardation defense is being used. This can be problematic because the training of the administrator and conditions under which the former exam was given are often unknown. Finally, issues of cross-cultural and linguistic misunderstandings and defendant malingering (exaggeration of intellectual limitations) are discussed. The over-arching theme of the article is that there are myriad intellectual tests available and each allows for the inference of many different meanings. Clinicians and lawyers alike should exercise care when determining the best way to approach expert testimony and assessments of intellectual functioning, particularly mental retardation.
Frumkin, I. (2006). Challenging expert testimony on intelligence and mental retardation. Journal Of Psychiatry & Law, 34(1), 51-71.