No Supreme Court Rule on Aggregating Multiple IQ Scores Under Atkins (Certiorari Dismissed as Improvidently Granted)

1. Introduction

Hamm v. Smith arose from Alabama’s effort to reinstate the death sentence of Joseph Clifton Smith, whose federal habeas petition succeeded on the ground that he is intellectually disabled and therefore ineligible for execution under Atkins v. Virginia, 536 U. S. 304 (2002). The litigation presented a recurring and practically important question in post-Atkins capital cases: when a defendant has taken multiple IQ tests with scores clustered above 70 but with standard-error ranges that sometimes extend to 70 or below, what method—if any—does the Eighth Amendment require for considering those multiple scores together?

The parties were John Q. Hamm, Commissioner of the Alabama Department of Corrections (petitioner), and Joseph Clifton Smith (respondent). Alabama sought Supreme Court review after the federal district court, affirmed by the Eleventh Circuit, concluded Smith satisfied Alabama’s three-pronged intellectual-disability definition (adopted after Atkins), despite five IQ scores between 72 and 78.

2. Summary of the Opinion

2.1 The per curiam disposition

The Court’s entire merits disposition is one sentence: “The writ of certiorari is dismissed as improvidently granted.” No constitutional holding was issued; no methodological test was adopted; the Eleventh Circuit’s judgment in favor of Smith remained intact.

2.2 Justice Sotomayor’s concurrence (joined by Justice Jackson)

Justice Sotomayor agreed that the case was a poor vehicle for any general rule about evaluating multiple IQ scores. She emphasized:

• The parties largely agreed the Eighth Amendment does not prescribe a single formula for aggregating multiple scores.
• The issue was not meaningfully litigated below: no expert computed composite/median/mean/overlap analyses; Alabama did not press a legal requirement to aggregate scores in a particular way in the district court or on appeal.
• Given the undeveloped record and absence of lower-court disagreement, the Court should not “leapfrog” experts and lower courts to pick among competing psychometric approaches.

Separately, she defended the district court’s “holistic” approach as consistent with Hall v. Florida, 572 U. S. 701 (2014), Moore v. Texas, 581 U. S. 1 (2017), medical diagnostic frameworks, and Alabama practice.

2.3 Justice Thomas’s dissent

Justice Thomas argued that the Court’s dismissal “rewards” Smith despite scores above 70 and used the case as a platform to urge overruling Atkins v. Virginia. His dissent focused on original meaning, asserting the Eighth Amendment addresses methods of punishment (not categorical offender exemptions) and that historical common-law protections for “idiots” do not support Atkins.

2.4 Justice Alito’s dissent (joined in parts by other Justices)

Justice Alito would have reached the merits to provide guidance on evaluating multiple IQ scores under Atkins. He criticized the lower courts’ reasoning as statistically and legally unsound, advocated “reasonably sound” methods (e.g., composite scores, median scores, central-tendency analyses), and argued that the district court impermissibly “deflated” Smith’s IQ using adaptive-functioning evidence, contrary to Moore v. Texas.

3. Analysis

3.1 Precedents Cited

Although the per curiam DIG adds no doctrinal test, the separate opinions are saturated with precedent. Those citations illuminate three competing jurisprudential instincts: (i) incrementalism/vehicle sensitivity (Sotomayor), (ii) administrability and quantitative rigor (Alito), and (iii) repudiation of the underlying doctrine (Thomas).

A. Foundational intellectual-disability capital cases

• Atkins v. Virginia, 536 U. S. 304 (2002):
  • Role in this case: The constitutional anchor: executing an intellectually disabled person violates the Eighth Amendment.
  • Key influence: Both Sotomayor and Alito stress Atkins “largely left it to the States” to develop enforcement methods, while still requiring courts to use medically informed frameworks. Thomas argues Atkins was wrongly decided and unworkable.
  • Practical tension exposed: Atkins created a constitutional bar but left definitional mechanics unresolved, setting the stage for disputes about IQ scores, standard errors, and evidentiary burdens.
• Penry v. Lynaugh, 492 U. S. 302 (1989):
  • Role in this case: Baseline history: prior to Atkins, intellectual disability was a mitigating factor, not a categorical exemption.
  • Influence: Sotomayor uses Penry to explain Smith’s original sentencing posture; Thomas uses it to underscore that the Court once “acknowledged the opposite” of Atkins.
• Hall v. Florida, 572 U. S. 701 (2014):
  • Role: The most relevant Supreme Court precedent on IQ evidence after Atkins.
  • Sotomayor’s reading: Hall rejects treating a single IQ score as conclusive and requires courts to account for the standard error of measurement; it permits considering other evidence (including adaptive deficits) even when scores are above 70.
  • Alito’s reading: Hall allows a 70 cutoff, but insists on confidence intervals for single scores; however, it does not answer how to treat multiple scores cumulatively—precisely why guidance is needed.
  • Importance in the vehicle debate: Sotomayor highlights Hall’s own observation that “the analysis of multiple IQ scores jointly is a complicated endeavor,” reinforcing that the Court previously avoided prescribing an algorithm.
• Moore v. Texas, 581 U. S. 1 (2017) and Moore v. Texas, 586 U. S. 133 (2019) (per curiam):
  • Role: Constrains state-court discretion by requiring alignment with medical diagnostic frameworks and by policing how courts reason from IQ scores and adaptive functioning.
  • Sotomayor’s use: The district court followed Moore by continuing the inquiry to adaptive functioning when standard-error ranges bring the score within the clinically relevant band; it did not “narrow” SEM based on individual-specific factors.
  • Alito’s use: The lower courts purportedly committed the Moore error in reverse—using adaptive-functioning facts to “deflate” IQ estimates, which he argues Moore prohibits.
• Brumfield v. Cain, 576 U. S. 305 (2015):
  • Role: Sotomayor cites it to support the proposition that Atkins adjudication often proceeds through state definitions, with federal courts applying state-law frameworks to the constitutional question.
  • Thomas’s use: Cited to reinforce his view that Atkins was understood to track an IQ ≤ 70 concept.

B. Vehicle, standard-of-review, and procedural posture authorities

• Hamm v. Smith, 604 U. S. 1 (2024) (per curiam):
  • Role: The Court’s earlier vacatur for clarification.
  • Influence: The 2024 decision frames the central ambiguity the Court ultimately declined to resolve in 2026—whether the Eleventh Circuit used a “per se rule” (lowest score’s SEM-bound) or a “holistic approach.” Sotomayor relies on the Eleventh Circuit’s clarification on remand to emphasize there was no per se rule.
  • Doctrinal takeaway: The Court reiterated in 2024—and Sotomayor repeats—that it “has not specified how courts should evaluate multiple IQ scores.” The 2026 DIG leaves that statement operative.
• Anderson v. Bessemer City, 470 U. S. 564 (1985):
  • Role: Sotomayor uses it to defend deference to trial-level factfinding (clear-error review), especially on credibility determinations among experts.
  • Influence: Reinforces her view that the dissent’s quarrel is essentially factual reweighing, not a clean legal question.
• Lebron v. National Railroad Passenger Corporation, 513 U. S. 374 (1995) and Hawk v. Olson, 326 U. S. 271 (1945):
  • Role: Alito cites them for party-presentation/preservation principles and burden allocation on habeas, arguing Alabama could advance supporting arguments at the Supreme Court stage and that Smith bore the burden of proving IQ ≤ 70.

C. Illustrative lower-court decisions (no split)

• Black v. Carpenter, 866 F. 3d 734 (CA6 2017) and Jackson v. Payne, 9 F. 4th 646 (CA8 2021):
  • Role: Sotomayor cites these to show federal appellate courts have managed multi-score records without evident confusion and without demanding a single aggregating formula.

D. Originalist and Eighth Amendment methodology disputes (Thomas dissent)

• Trop v. Dulles, 356 U. S. 86 (1958):
  • Role: Thomas uses it to criticize the “evolving standards of decency” method deployed in Atkins.
• Grants Pass v. Johnson, 603 U. S. 520 (2024), Bucklew v. Precythe, 587 U. S. 119 (2019), In re Kemmler, 136 U. S. 436 (1890), Baze v. Rees, 553 U. S. 35 (2008):
  • Role: Thomas relies on these to argue the Eighth Amendment concerns methods of punishment and does not support categorical offender exclusions like Atkins.
• Gamble v. United States, 587 U. S. 678 (2019), Ramos v. Louisiana, 590 U. S. 83 (2020), Dobbs v. Jackson Women's Health Organization, 597 U. S. 215 (2022), Glossip v. Gross, 576 U. S. 863 (2015):
  • Role: Used to argue stare decisis should not protect Atkins and to situate Atkins among “egregious” Eighth Amendment rulings.

3.2 Legal Reasoning

A. What the Court actually did (and did not do)

The per curiam order did not adopt any IQ aggregation standard, did not interpret Hall v. Florida or Moore v. Texas, and did not resolve whether adaptive-functioning evidence may inform intellectual-functioning determinations in multi-score cases. A DIG is, functionally, a decision not to decide.

The controlling “reasoning” is therefore best understood as institutional: the Court concluded that granting review was a mistake given the posture and presentation of the question, and it left the lower-court judgment undisturbed without endorsing its rationale.

B. Sotomayor’s vehicle-based justification for the DIG

C. Alito’s administrability critique (and proposed guidance)

Justice Alito’s dissent treats the Court’s avoidance as a failure of stewardship in death penalty doctrine. He argues that Atkins created doctrinal ambiguity; Hall and Moore constitutionalized some IQ-score rules; and the remaining gap—how to treat multiple scores—predictably recurs. In his view, the Court should either:

• Reverse because the lower courts used an invalid approach (either a “one-low-score” logic or impermissible “deflation” of IQ using adaptive-functioning evidence), or
• At minimum, remand for reanalysis under any “sound method,” offering examples such as composite scoring, median scoring, or expert central-tendency assessment.

Alito’s deeper jurisprudential concern is the perceived drift toward “holistic” standards that, he argues, risk turning IQ cutoffs into a “perfunctory formality,” producing expert-driven, less predictable outcomes.

D. Thomas’s call to overrule Atkins

Justice Thomas uses the case to argue that Atkins is textually and historically unfounded and practically unworkable. His reasoning is not about multi-score aggregation; it is about undoing the entire constitutional category. The DIG, in his telling, exemplifies doctrinal “confusion and absurdity.”

3.3 Impact

A. Immediate legal effect

• No new Supreme Court standard governs how courts must consider “the cumulative effect of multiple IQ scores” under Atkins v. Virginia.
• The Eleventh Circuit’s affirmance of federal habeas relief for Smith remains in place, but without Supreme Court endorsement of its reasoning.

B. Practical effects on litigation strategy

• Record development becomes decisive. Justice Sotomayor’s concurrence signals that if parties want a Supreme Court rule on score aggregation, they must litigate that question explicitly below—introducing expert testimony and calculations (composites, overlap analyses, medians, etc.) and preserving objections.
• “Holistic” assessment remains the safe harbor. In the absence of a mandated algorithm, trial courts will likely continue to (i) apply the SEM to each score, (ii) consider expert interpretation of score validity, and (iii) consider adaptive functioning and developmental history—especially in borderline-score cases.
• Continued doctrinal pressure. Alito predicts recurring petitions; Thomas invites direct challenges seeking to overrule Atkins. The DIG delays resolution but does not defuse the conflict among methodological preferences.

C. Federalism and state-law definitions

Sotomayor underscores that Atkins left substantial room for state definitions (here, Alabama’s three-prong definition from Ex parte Perkins, 851 So. 2d 453 (2002)). The DIG leaves states free to legislate or adjudicate aggregation methods, subject to the outer constraints of Hall v. Florida and Moore v. Texas (SEM must be respected; courts must not apply criteria in ways that contradict medical frameworks or artificially narrow statistical uncertainty).

4. Complex Concepts Simplified

• Certiorari “dismissed as improvidently granted” (DIG): The Supreme Court initially agreed to hear the case but later decided it should not have taken it (often because the issue is not cleanly presented, was not preserved, or the record is inadequate). A DIG decides nothing on the merits.
• Atkins claim: A postconviction claim that the Eighth Amendment bars executing the defendant because the defendant is intellectually disabled.
• IQ score vs. “true” IQ: A test score is an estimate. A person’s “true” IQ (as used in psychometrics) is a statistical concept: roughly, the average score the person would get over many valid administrations.
• Standard error of measurement (SEM): The built-in uncertainty of an IQ test. Courts use SEM to create a range around a score rather than treating the score as exact.
• Confidence interval: A range derived from the SEM that reflects where the person’s true score is likely to fall (e.g., a score of 72 might correspond to a range that includes values below and above 70).
• “Holistic” approach (in this context): Looking at all IQ scores with their error ranges, plus expert testimony about validity and meaning, and other evidence bearing on intellectual functioning and adaptive deficits—rather than applying a single mechanical aggregation formula.
• Adaptive functioning: Real-world skills (conceptual, social, practical) such as communication, self-direction, and everyday independence. Under most clinical and legal definitions, intellectual disability requires both intellectual deficits (often operationalized with IQ) and adaptive deficits.
• 28 U. S. C. §2254(d) deference vs. de novo review: Federal habeas courts typically must defer to reasonable state-court adjudications under §2254(d). Here, earlier proceedings led to a de novo federal determination under Alabama’s definition after the Eleventh Circuit found improper deference.
• Clear-error review: Appellate courts usually do not reweigh factfinding from trial courts, especially when credibility of experts is central. Sotomayor invokes this to argue the dissents are effectively seeking forbidden reweighing.

5. Conclusion

Hamm v. Smith establishes no new merits precedent because the Court dismissed certiorari as improvidently granted. Nonetheless, the decision is significant for what it leaves unresolved: the Supreme Court still “has not specified how courts should evaluate multiple IQ scores” in Atkins litigation.

Justice Sotomayor’s concurrence frames the DIG as a vehicle-and-record decision, warning against premature constitutionalization of disputed psychometric methodology and implicitly encouraging percolation in lower courts with properly developed expert evidence. Justice Alito’s dissent, by contrast, treats the lack of guidance as a threat to administrability and consistency in capital cases and urges acceptance of recognized aggregation tools. Justice Thomas uses the case to renew a direct attack on Atkins itself.

The key takeaway for practitioners and courts is practical rather than doctrinal: unless and until the Supreme Court takes a cleaner case, the governing constraints remain Atkins v. Virginia, Hall v. Florida, and Moore v. Texas, while the specific method for synthesizing multiple IQ scores will continue to be litigated—and will likely turn on record development, expert proof, and trial-level factfinding.