The U.S. Supreme Court has ruled in Hall v. Florida, an important (though little followed) case involving the standard for intellectual disability. Florida state law imposes a bright-line threshold test in cases of alleged incapacity. If the person has an IQ of 70 or above, the court will not consider such a disability claim. It is an approach that has been widely ridiculed by experts and now, in a 5-4 decision, Justice Anthony M. Kennedy has ruled that such a rule violated the Eighth Amendment and runs counter to recognized scientific standards. My Supreme Court class reviewed Hall and reached the same conclusion, though the vote was almost unanimous. The class voted 13-1 to reverse lower court. The class however got it wrong on the prediction. In a close 8-6 vote, the class predicted that the Supreme Court would affirm.

The case involves a particularly gruesome crime scene that makes it difficult for most people to have much sympathy for the culprits. On February 21, 1978, Freddie Lee Hall, and his accomplice, Mark Ruffin, kidnaped, beat, raped, and murdered Karol Hurst. Hurst was a pregnant, 21-year-old newlywed. The two men then drove to a convenience store to rob it but encountered Lonnie Coburn, a sheriff’s deputy who attempted to apprehend them was subsequently killed. Hall received the death penalty for both murders, but his sentence for the Coburn murder was later reduced on account of insufficient evidence of premeditation. Hall v. Florida, 403 So. 2d 1319 , 1321 (Fla. 1981) (per curiam).

At the time of the sentence, the Supreme Court had not yet ruled that the Eighth Amendment prohibits States from imposing the death penalty on persons with intellectual disability. See Penry v. Lynaugh, 492 U.S. 302 , 340 (1989). Indeed, Florida law did not even recognize intellectual disability as a statutory mitigating factor.

The opinion is an important return to the area of intellectual disability since the Court’s 2002 decision in Atkins v. Virginia. In that case, the Court ruled that executing the mentally retarded violates the Constitution’s prohibition against cruel and unusual punishment. However, the Court left it to states on defining intellectual disability. In addition to Florida, Virginia and Kentucky also use this type of threshold test.

The majority reaffirmed the bar on executing the intellectually disabled:

No legitimate penological purpose is served by executing a person with intellectual disability. Id., at 317 , 320 . To do so contravenes the Eighth Amendment , for to impose the harshest of punishments on an intellectually disabled person violates his or her inherent dignity as a human being. “[P]unishment is justified under one or more of three principal rationales: rehabilitation, deterrence, and retribution.” Kennedy v. Louisiana, 554 U.S. 407 , 420 (2008). Rehabilitation, it is evident, is not an applicable rationale for the death penalty. See Gregg v. Georgia, 428 U.S. 153 , 183 (1976) (joint opinion of Stewart, Powell, and Stevens, JJ.). As for deterrence, those with intellectual disability are, by reason of their condition, likely unable to make the calculated judgments that are the premise for the deterrence rationale. They have a “diminished ability” to “process information, to learn from experience, to engage in logical reasoning, or to control impulses . . . [which] make[s] it less likely that they can process the information of the possibility of execution as a penalty and, as a result, control their conduct based upon that information.” Atkins, 536 U.S., at 320 . Retributive values are also ill-served by executing those with intellectual disability. The diminished capacity of the intellectually disabled lessens moral culpability and hence the retributive value of the punishment. See id., at 319 (“If the culpability of the average murderer is insufficient to justify the most extreme sanction available to the State, the lesser culpability of the mentally retarded offender surely does not merit that form of retribution”).

A further reason for not imposing the death penalty on a person who is intellectually disabled is to protect the integrity of the trial process. These persons face “a special risk of wrongful execution” because they are more likely to give false confessions, are often poor witnesses, and are less able to give meaningful assistance to their counsel. Id., at 320-321 . This is not to say that under current law persons with intellectual disability who “meet the law’s requirements for criminal responsibility” may not be tried and punished. Id., at 306 . They may not, however, receive the law’s most severe sentence. Id., at 318 .

Kennedy follows with a detailed discussion of the use (and the limits) of the IQ test:

The professionals who design, administer, and interpret IQ tests have agreed, for years now, that IQ test scores should be read not as a single fixed number but as a range. See D. Wechsler, The Measurement of Adult Intelligence 133 (3d ed. 1944) (reporting the range of error on an early IQ test). Each IQ test has a “standard error of measurement,” ibid., often referred to by the abbreviation “SEM.” A test’s SEM is a statistical fact, a reflection of the inherent imprecision of the test itself. See R. Furr & V. Bacharach, Psychometrics 118 (2d ed. 2014) (identifying the SEM as “one of the most important concepts in measurement theory”). An individual’s IQ test score on any given exam may fluctuate for a variety of reasons. These include the test-taker’s health; practice from earlier tests; the environment or location of the test; the examiner’s demeanor; the subjective judgment involved in scoring certain questions on the exam; and simple lucky guessing. See American Association on Intellectual and Developmental Disabilities, R. Schalock et al., User’s Guide To Accompany the 11th Edition of Intellectual Disability: [*9] Definition, Classification, and Systems of Supports 22 (2012) (hereinafter AAIDD Manual); A. Kaufman, IQ Testing 101, pp. 138-139 (2009).

The SEM reflects the reality that an individual’s intellectual functioning cannot be reduced to a single numerical score. For purposes of most IQ tests, the SEM means that an individual’s score is best understood as a range of scores on either side of the recorded score. The SEM allows clinicians to calculate a range within which one may say an individual’s true IQ score lies. See APA Brief 23 (“SEM is a unit of measurement: 1 SEM equates to a confidence of 68% that the measured score falls within a given score range, while 2 SEM provides a 95% confidence level that the measured score is within a broader range”). A score of 71, for instance, is generally considered to reflect a range between 66 and 76 with 95% confidence and a range of 68.5 and 73.5 with a 68% confidence. See DSM-5, at 37 (“Individuals with intellectual disability have scores of approximately two standard deviations or more below the population mean, including a margin for measurement error (generally +5 points). . . . [T]his involves a score of 65-75 (70 ± 5)”); APA Brief 23 (“For example, the average SEM for the WAIS-IV is 2.16 IQ test points and the average SEM for the Stanford-Binet 5 is 2.30 IQ test points (test manuals report SEMs by different age groupings; these scores are similar, but not identical, often due to sampling error)”). Even when a person has taken multiple tests, each separate score must be assessed using the SEM, and the analysis of multiple IQ scores jointly is a complicated endeavor. See Schneider, Principles of Assessment of Aptitude and Achievement, in The Oxford Handbook of Child Psychological Assessment 286, 289-291, 318 (D. Saklofske, C. Reynolds, V. Schwean, eds. 2013). In addition, because the test itself may be flawed, or administered in a consistently flawed manner, multiple examinations may result in repeated similar scores, so that even a consistent score is not conclusive evidence of intellectual functioning.

Despite these professional explanations, Florida law used the test score as a fixed number, thus barring further consideration of other evidence bearing on the question of intellectual disability. For professionals to diagnose-and for the law then to determine-whether an intellectual disability exists once the SEM applies and the individual’s IQ score is 75 or below the inquiry would consider factors indicating whether the person had deficits in adaptive functioning. These include evidence of past performance, environment, and upbringing.

The decision obviously curtails the right of the states to set such standards, something that Justice Samuel A. Alito Jr., called a “sea change” in the court’s approach. What is interesting is that Alito takes a shot at the experts in this field in calling them elitist and calls for the law to follow the view of the common people on such questions: “What counts are our society’s standards — which is to say, the standards of the American people — not the standards of professional associations, which at best represent the views of a small professional elite.” Of course, mental and intellectual disability is capable of objective testing and measurement. While it is hardly precise and not without controversy, the suggestion that we should reject the view of experts as “elitists” sounds like something you would hear on cable news from commentators like Sarah Palin.

Writing for Chief Justice Roberts and Associate Justices Scalia, and Thomas, Alito wrote:

First, because the views of professional associations often change, 7 tying Eighth Amendment law to these views will lead to instability and continue to fuel pro-tracted litigation. This danger is dramatically illustrated by the most recent publication of the APA, on which the Court relies. This publication fundamentally alters the first prong of the longstanding, two-pronged definition of intellectual disability that was embraced by Atkins and has been adopted by most States. In this new publication, the APA discards “significantly subaverage intellectual functioning” as an element of the intellectual-disability test. 8 Elevating the APA’s current views to constitutional significance therefore throws into question the basic approach that Atkins approved and that most of the States have followed.

It is also noteworthy that changes adopted by professional associations are sometimes rescinded. For example, in 1992 the AAIDD extended the baseline “intellectual functioning cutoff” from an “IQ of 70 or below” to a “score of approximately 70 to 75 or below.” AAIDD 11th ed. 10 (Table 1.3) (boldface deleted); see 2 Kaplan & Sadock’s Comprehensive Textbook of Psychiatry 3449 (B. Sadock, V. Sadock, & P. Ruiz eds., 9th ed. 2009) (hereinafter Kaplan & Sadock’s). That change “generated much controversy’; by 2000, “only 4 states used the 1992 AAIDD definition, with 44 states continuing to use the 1983 definition.” Ibid. And in the 2002 AAIDD, the baseline “IQ cut-off was changed” back to approximately “70 or less.” Ibid.

Second, the Court’s approach implicitly calls upon the Judiciary either to follow every new change in the thinking of these professional organizations or to judge the validity of each new change. Here, for example, the Court tacitly makes the judgment that the diagnostic criteria for intellectual disability that prevailed at the time when Atkins was decided are no longer legitimate. The publications that Atkins cited differ markedly from more recent editions now endorsed by the Court. See 536 U.S., at 308 , n. 3.

Third, the Court’s approach requires the Judiciary to determine which professional organizations are entitled to special deference. And what if professional organizations disagree? The Court provides no guidance for deciding which organizations’ views should govern.

Fourth, the Court binds Eighth Amendment law to definitions of intellectual disability that are promulgated for use in making a variety of decisions that are quite different from the decision whether the imposition of a death sentence in a particular case would serve a valid penological end. In a death-penalty case, intellectual functioning is important because of its correlation with the ability to understand the gravity of the crime and the purpose of the penalty, as well as the ability to resist a momentary impulse or the influence of others. See id., at 318 , 320. By contrast, in determining eligibility [*21] for social services, adaptive functioning may be much more important. Cf. DSM-IV-TR, at xxxvii (clinical “considerations” may not be “relevant to legal judgments” that turn on “individual responsibility”); DSM-5, at 20 (similar). Practical problems like these call for legislative judgments, not judicial resolution.

In our class, we discussed the need to get beyond the anger and disgust over the crime committed by Hall to focus on this question of the standard for intellectual disability. In the end, the class was virtually unanimous that the test applied by Florida was arbitrary and would deny the use of the defense to some defendants who were clearly disabled. While it is true that this is a difficult question, the Florida law was not viewed as a close question. By barring the ability of the defendant to submit evidence of disability because he received a 71 seemed entirely without medical or logical basis. As Kennedy notes, “Intellectual disability is a condition, not a number.”

Kennedy was joined by Justices Ruth Bader Ginsburg, Stephen G. Breyer, Sonia Sotomayor and Elena Kagan.

Here is the opinion.