See prior post regarding Hamm v Smith Atkins ID death penalty case where central issue is how to handle multiple IQ scores. All briefs are at that prior blog post page.
Oral arguments before the SCOTUS justices occurred this past Wednesday, 12-10-25. One can download audio file (arguments lasted 2 hours) or transcript of arguments at this link.
Clinical judgment is a process based on solid scientific knowledge and is characterized as being “systematic (i.e., organized, sequential, and logical), formal (i.e., explicit and reasoned), and transparent (i.e., apparent and communicated clearly)” (Schalock & Luckasson, 2005, p.1). The application of clinical judgment in the evaluation of IQ scores in the diagnosis of intellectual disability includes consideration of multiple factors that might influence the accuracy of an assessment of general intellectual ability (APA: DSM-5, 2013). The “unanimous professional consensus that the diagnosis of intellectual disability requires comprehensive assessment and the application of clinical judgment” (Brief of Amici Curiae American Psychological Association, American Psychiatric Association, American Academy of Psychiatry and the Law, Florida Psychological Association, National Association of Social Workers, and National Association of Social Workers Florida Chapter, in Support of Petitioner; Hall v. Florida; S.Ct., No. 12-10882; 2014; p. 8).
The misuse of clinical judgment in the interpretation of scores from intelligence test batteries should not be used as the basis for “gut instinct” or “seat-of-the-pants” impressions and conclusions of the assessment professional (Macvaugh & Cunningham, 2009), or justification for shortened evaluations, a means to convey stereotypes or prejudices, a substitute for insufficiently explored questions, or an excuse for incomplete testing and missing data (Schalock & Luckasson, 2005). Idiosyncratic methods and intuitive conclusions are not scientifically based and have unknown reliability and validity.
If clinical judgment interpretations and opinions regarding an individual’s level of general intelligence are based on novel or emerging research-based principles, the assessment professional must document the bases for these new interpretations as well as the limitations of these principles and methods. This requirement is consistent with the Standards for Educational and Psychological Testing Standard 9.4 which states:
When a test is to be used for a purpose for which little or no validity evidence is available, the user is responsible for documenting the rationale for the selection of the test and obtaining evidence of the reliability/precision of the test scores and the validity of the interpretations supporting the use of the scores for this purpose (p. 143).
American Educational Research Association, American Psychological Association, & National Council on Measurement in Education (2014). Standards for educational and psychological testing. Washington, DC: Author.
American Psychiatric Association (2013). Diagnostic and statistical manual of mental disorders— Fifth Edition. Washington D.C.: Author.
Brief of Amici Curiae American Psychological Association, American Psychiatric Association, American Academy of Psychiatry and the Law, Florida Psychological Association, National Association of Social Workers, and National Association of Social Workers Florida Chapter, in Support of Petitioner; Hall v. Florida; S.Ct., No. 12-10882; 2014; p. 8.
MacVaugh, G. S. & Cunningham, M. D. (2009). Atkins v. Virginia: Implications and recommendations for forensic practice. The Journal of Psychiatry and Law, 37, 131-187.
Schalock, R. L. & Luckasson, R. (2005). Clinical judgment. Washington, DC: American Association on Intellectual and Developmental Disabilities.
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Kevin S. McGrew, PhD.
Educational Psychologist
Director
Institute for Applied Psychometrics (IAP)
Generated by: Tag Generator
This study used the Woodcock-Johnson Tests of Cognitive Ability-Revised to investigate a wide range of cognitive abilities in people with Williams syndrome (WS). It involved a comparatively large sample of 31 people with WS, but took a case-series approach. The study addressed the widespread claims of a characteristic "WS cognitive profile" by looking for heterogeneity rather than homogeneity. People with WS showed a variety of preserved (significantly above mental age [MA]), expected (at MA), and significantly impaired (significantly below MA) levels of functioning. Such results provide clear evidence for heterogeneity in cognitive functions within WS. We found the most homogeneity on a test of phonological processing and a test of phonological short-term memory, with half of the WS sample performing at MA levels on these tests. Interestingly, no WS individual showed a weakness on a test of nonverbal reasoning, and only one WS individual showed a weakness on a test of verbal comprehension. In addition, we found that strengths on analysis-synthesis and verbal analogies occurred only for WS individuals with an MA less than 5.5 years (our sample median MA); people with an MA greater than 5.5 years performed at MA level on these 2 tests. Results also provided preliminary evidence for distinct subgroups of WS people based on their cognitive strengths and weaknesses on a broad range of cognitive functions. On the basis of the findings, caution should be made in declaring a single cognitive profile that is characteristic of all individuals with WS. Just as there is heterogeneity in genetic and physical anomalies within WS, not all WS individuals share the same cognitive strengths and weaknesses. Also, not all WS individuals show the profile of a strength in verbal abilities and a weakness in spatial functions.
Description of presentation: This presentation traces the evolution of psychometric theories of intelligence from Spearman's g to contemporary CHC. In addition, it simultaneously tracks the evolution of psychometric tests of intelligence as they relate to psychometric theories. Finally, there is a special emphasis on tracking changes in the AAMR/AAIDD intellectual disability (mental retardation) classification manuals over the same period. It is concluded that despite significant advances in psychometric theories of intelligence and contemporary psychometric intelligence tests, the official 2010 AAIDD manual is significantly behind these developments. The 2010 AAIDD manual is "stuck on g" and has failed to incorporate advances in both psychometric theories and tests of intelligence. A significant intelligence theory--AAIDD ID/MR definition gap exists tat has potential serious consequences for individuals with ID/MR.
Despite the widespread acceptance and recognition of the contemporary CHC (aka Extended Gf-Gc) theory of intelligence by intelligence scholars, a 2002 national panel of MR/ID experts, and the clear movement in applied IQ test development to test batteries grounded in the CHC framework, AAIDD continues to be “stuck on g”
The AAIDD definition of intelligence is out-of-date. A major intelligence theory—AAIDD ID definition gap exists
Contemporary intelligence scholars, experts, and test developers recognize that although g (general intelligence) may exist at the apex of the CHC taxonomy of human cognitive abilities, there are broad (stratum II) abilities that are important (i.e., have differential validities) that can be assessed and, when interpreted appropriately, can provide a more valid and multidimensional picture of an individuals intellectual functioning.
AAIDD’s continued use of the statement (with regard to measurement of multiple cognitive abilities) that “until such measures of multiple intelligences can be assessed reliably and validly, it is the position of AAIDD that intellectual functioning…is best conceptualized and captured by a general factor of intelligence” is simply wrong! Reliable and valid measures of the broad CHC ability domains exist and have been published in most intelligence batteries published from 1989 to 2008.
The AAIDD g-position is at odds with the known heterogeneity of abilities within the ID (and general) population and fails to recognize that although a g-based total composite score may often represent the best single index of a person’s intellectual functioning, often the g-based composite score may lead to inaccurate conclusions regarding a person’s intellectual functioning and in these cases more attention should be focused on the component part scores. The stuck on g position has the potential to result in serious consequences for individuals, such as denial of special education services; denial of SS benefits, and unjust execution as in “Atkins MR/ID death penalty cases”.
“Two clinical psychologists testified for the Commonwealth in rebuttal to [the defense expert’s] testimony. Dr. Lynda J. Hyatt reported that Green had an I.Q. score of 84 on the ‘Ammons & Ammons quick test,’ which placed Green in the category of ‘low average’ mental functioning. Dr. Thomas A. Pasquale evaluated Green’s personality as well as his intellectual functioning. Dr. Pasquale diagnosed depression, alcohol dependency, drug abuse, anti-social personality disorder, and malingering. According to Dr. Pasquale, Green had a full-scale I.Q. score of 74 on the Weschler Adult Intelligence Scale, placing him in the ‘borderline range’ of intellectual functioning.”[4]
“The experts testifying during the evidentiary hearing disagree on whether Green was malingering when he took his IQ tests, and disagreed on how to determine when a person is malingering. However, there is no indication Green would have been malingering at the age of thirteen when he was administered the WISC-R, and received a score of 71. . . The Court finds that Green had no incentive to malinger on the WISC-R, and his score on that test is the best indication of his intellectual functioning as demonstrated on a measure of intellectual functioning prior to the age of eighteen years.”[7]The magistrate judge went on to add,
“Based on all of the evidence presented, this Court finds that Green has met his burden of proving by a preponderance of the evidence ‘significantly subaverage intellectual functioning [which originated before the age of 18 years] as demonstrated by performance on a standardized measure of intellectual functioning administered in conformity with accepted professional practice’”.[8]The magistrate judge dropped the ball. First, he should have decided the malingering issue. Second, he was wrong when he ruled that the IQ test score from age 13 sufficed to prove “‘significantly subaverage intellectual functioning [which originated before the age of 18 years] as demonstrated by performance on a standardized measure of intellectual functioning administered in conformity with accepted professional practice’”. The court was quoting from the applicable statute, Virginia Code § 19.2-264.3:1.1, which defines mental retardation as, “a disability, originating before the age of 18 years, characterized concurrently by (i) significantly subaverage intellectual functioning as demonstrated by performance on a standardized measure of intellectual functioning administered in conformity with accepted professional practice . . . and (ii) significant limitations in adaptive behavior”. The statute goes on to state that, “ Assessment of intellectual functioning shall include administration of at least one standardized measure generally accepted by the field of psychological testing and appropriate for administration to the particular defendant being assessed . . . Testing of intellectual functioning shall be carried out in conformity with accepted professional practice” (emphasis added). As with the major definitions of mental retardation, the Virginia statute makes it clear that the assessment of mental retardation requires results from current IQ testing, along with a current assessment of adaptive behavior, coupled with evidence showing onset before age 18. The magistrate judge’s quote left out the highlighted words from the statute, and made it appear that the statute only requires an IQ score from before age 18. This is an example of creative judging, but not good judging.
“Additional errors were suggested by Green’s counsel, during cross-examination, based on how [the prosecution expert] scored specific questions on the test. Further, [one of the Green’s experts] testified that based on the raw data from Green’s WAIS-III test, [the defense expert] would have assigned a score of 72. This Court does not condone re-scoring of IQ tests or adjustment of scores based on an interpretation of the raw data after the fact. [The prosecution expert], as well as other psychologists, are trained in the administration and scoring of IQ tests. It is not for the Court to go behind those scores, and question the psychologists’ conclusions. The statute requires that IQ tests be administered and scored ‘in accordance with accepted professional practice’ . . . Green has not alleged that [the prosecution expert’s] administration of the WAIS-III failed this requirement. Therefore, the score will be accepted as assigned by [the prosecution expert].”[10]
