Whether and how courts may consider the cumulative effect of multiple IQ scores in assessing an *Atkins* claim. The Court specifically addressed whether a "holistic approach" to multiple scores is permissible or if a specific mathematical aggregation is required. This inquiry arises from a dispute over whether a respondent with multiple scores above 70 can still be found intellectually disabled.

Petitioner sought to reverse the lower court's finding that the respondent is intellectually disabled. Petitioner argued that a State can require a claimant to prove an IQ of 70 or less by a preponderance of the evidence. Petitioner further contended that courts must consider the "cumulative effect" of multiple scores using methods such as taking the median, average, or highest score to prove an IQ of 70 or below.

Respondent sought to maintain the lower court's ruling that he is intellectually disabled and cannot be executed. Respondent argued that courts must assess multiple IQ scores "holistically," which includes considering those scores in light of expert testimony and other evidence of intellectual functioning. Respondent contended that this approach is consistent with the medical community's diagnostic framework and existing Eighth Amendment precedents.

The Court dismissed the writ of certiorari as improvidently granted. It declined to provide detailed guidance on how courts should assess multiple IQ scores. The Court noted that the parties agree the Eighth Amendment does not prescribe a single formula for weighing multiple IQ scores. It observed that *Atkins v. Virginia* left States the primary role in "developing appropriate ways to enforce" the prohibition against executing the intellectually disabled. The Court found that the specific issue of how to combine multiple scores was not meaningfully raised or passed upon in the proceedings below. It reasoned that it is not equipped to provide meaningful guidance without an evidentiary record trained on the specific theories now advanced by the parties. The Court highlighted that there is no current split among lower courts on this specific issue. It emphasized that it should not leapfrog state courts and federal lower courts to provide conclusive guidance in the first instance. The Court relied on the principle that the legal determination of intellectual disability is informed by the medical community's diagnostic framework. Consequently, the Court determined that the current case was an inappropriate vehicle for establishing a national rule on the aggregation of IQ scores.

Justice Alito, joined by Justice Thomas (and the Chief Justice and Justice Gorsuch in part), argued that the Court should have provided "much-needed guidance" on evaluating multiple IQ scores to avoid "arbitrary and unpredictable" outcomes. He contended that the lower courts' "holistic" approach contravened psychology and statistics, citing *Hall v. Florida* and *Moore v. Texas* to argue for more objective methods like composite scores or median values. Justice Thomas further argued that *Atkins v. Virginia* is "demonstrably erroneous" and should be overruled entirely as it lacks support in the original meaning of the Eighth Amendment.