SCOTUS to Determine Definition of Intellectual Disability
The United States Supreme Court could soon give greater clarity to how intellectual disability is determined. On December 10, 2025, the Court heard oral arguments in Hamm v. Smith, a case that involves an Alabama death-row inmate who may escape the death sentence depending on whether he is found to be intellectually disabled. At issue is whether IQ test scores alone are sufficient when determining if a person is intellectually disabled — a designation that under U.S. law can make someone ineligible for the death penalty.
What This Case Is About
This case involves Joseph Clifton Smith, who was convicted in Alabama of a 1997 murder and sentenced to death. In postconviction proceedings, Smith’s legal team argued that he is intellectually disabled, which, under the 2002 Supreme Court decision Atkins v. Virginia, means he is not allowed to be executed.
Smith has taken five full-scale IQ tests, with scores ranging from 72 to 78. Because IQ tests are not exact, the lowest of his scores (72) could theoretically reflect a “true” IQ as low as 69, once the standard error of measurement is accounted for. That estimate played a big role in a lower court judge’s decision to vacate Smith’s death sentence.
The U.S. Court of Appeals for the Eleventh Circuit affirmed the lower court’s decision, using what it described as a holistic approach. It considered all five IQ scores plus expert testimony about Smith’s difficulties in self-direction, social and interpersonal skills, independent home living, education, and other adaptive deficits.
Why the Supreme Court Is Involved
When Smith’s case first reached the Supreme Court in 2024, the justices did not immediately rule on it. Instead, they vacated (set aside) the Eleventh Circuit’s ruling and sent it back for clarification, noting that the lower court’s opinion was ambiguous. On one reading, it seemed to treat Smith’s lowest possible IQ score (69) as decisive. On another, it suggested a more balanced, evidence-wide analysis.
After the remand, the Eleventh Circuit made clear it was relying on the holistic approach, which included not just the low-end IQ estimate, but all his test results and expert views on his functioning. Alabama then appealed again, asking the Supreme Court to clarify what standard should apply when someone submits multiple IQ scores in a death-penalty case.
What’s at Stake
This case could determine more than just Smith’s life.
Legal Clarity for Capital Cases
If the Supreme Court endorses a holistic standard, courts would be required to consider the full picture — all IQ scores, not just one number, plus how a person functions in daily life. But if the Court instead rules that the lowest possible score after adjusting for error should decide, it could set a stricter rule that makes it harder for some people to qualify as intellectually disabled.
Effects on People With Intellectual Disabilities
For people with borderline or variable IQ test results, this could be a life-or-death decision. A ruling that supports holistic evaluation would validate expert testimony about adaptive behavior (how someone copes, learns, interacts), not just raw test scores. That matters for fairness and dignity, since intellectual disability is more than just a number.
Broader Implications
Though this case directly concerns the death penalty, how the courts treat IQ testing could influence other areas, such as criminal sentencing, disability benefits, and eligibility for services.
Science Meets Law
The case is also a reminder of the limits of standardized testing. IQ tests have known margins of error. Courts must grapple with statistical uncertainty and decide how much weight to give to that uncertainty when making life-altering decisions.
Why It Matters Now
The Supreme Court has recognized that how intellectual disability is defined affects more areas of life than just who is exempt from the death penalty. The outcome of this case could determine how individuals are classified as disabled and are therefore eligible for Social Security benefits, extra educational services, and other accommodations. A decision in the case is expected by late June or early July.
