STEVENS, J., dissenting reasons for deciding not to impose . . . a death sentence. . ., App. 186. But immediately afterwards, he instructed the jury to "pay careful attention to each of these factors. Any one of them standing alone may support a decision that death is not the appropriate punishment in this case." Ibid. (emphasis added). Since none of "these factors" (save for the age of the defendant) encompassed any mitigating circumstance unrelated to the severity of the crime, the most natural reading of the instruction is that any mitigating factor that lessens the severity of the offense may support a sentence other than death. On this view, any other mitigating circumstance is simply irrelevant to (in the prosecutor's words) the "simple weighing" the jury was tasked with performing. Id., at 150. V Questions asked by at least six different jurors during almost two full days of deliberation gave the judge an ample opportunity to clarify that the testimony offered on behalf of respondent, if credited by the jury, provided a permissible basis for imposing a sentence other than death. Far from eliminating their obvious confusion, his responses cemented the impression that the jurors' lone duty was to weigh specified, limited statutory factors against each other. After a lunch break, the judge reconvened the jury to answer a question that does not appear in the record; in response, the judge merely reread instructions telling the jury that it "must agree, if [it] can," and that it "shall consider, take into account and be guided by the applicable factors of aggravating and mitigating circumstances upon which you have been instructed." Id., at 185, 188-189 (emphasis added). Because all of those factors were traditional sentencing factors, and because none of them permitted consideration of Skipper-type mitigating evidence, the judge's response was the functional equivalent of yet another admonition to disregard most of respondent's evidence. STEVENS, J., dissenting After a colloquy between the judge and four different jurors (Hailstone, Wilson, Norton, and Huckabay) about the likelihood of reaching a unanimous verdict,3 other jurors asked the judge a series of questions reflecting a concern about whether it was proper to consider aggravating or mitigating circumstances other than those specifically listed in his instructions: "JUROR HERN: The statement about the aggravation and mitigation of the circumstances, now, that was the listing? "THE COURT: That was the listing, yes, ma'am. "JUROR HERN: Of those certain factors we were to decide one or the other and then balance the sheet? "THE COURT: That is right. It is a balancing process. Mr. Meyer? "JUROR MEYER: A specific question, would this be an either/or situation, not a one, if you cannot the other? "THE COURT: No. It is not that. "JUROR MEYER: It is an either/or situation? 3“JUROR HAILSTONE: If we can't, Judge, what happens? "THE COURT: I can't tell you that. "JUROR WILSON: That is what we wanted to know. "THE COURT: Okay. I know what will happen, but I can't tell you what will happen. "MR. SCHICK: Maybe we should inquire whether the jury could reach a verdict. "THE COURT: Do you think, Mr. Norton, you will be able to make a decision in this matter? "JUROR HAILSTONE: Not the way it is going. "JUROR NORTON: That is tough, yes. "THE COURT: Do you think if I allow you to continue to discuss the matter and for you to go over the instructions again with one another, that the possibility of making a decision is there? "JUROR NORTON: I believe there is a possibility. "JUROR HUCKABAY: We did need more time. "THE COURT: I think so. I think you need more time." App. 190-191. STEVENS, J., dissenting "THE COURT: Exactly. If you can make that either/or decision. If you cannot, then I will discharge you. "JUROR HAILSTONE: Could I ask a question? I don't know if it is permissible. Is it possible that he could have psychiatric treatment during this time? "THE COURT: That is something you cannot consider in making your decision." App. 191. The judge's responses strongly suggest that the "listing"-the listed statutory factors-was all that the jury could properly consider when "balanc[ing] the sheet." See n. 1, supra. But it is difficult, if not impossible, to see how evidence relating to future conduct even arguably "extenuate[d] the gravity of the crime" under factor (k), and none of those listed factors gave the jury the chance to consider whether respondent might redeem himself in prison. Cf. Brown v. Payton, 544 U. S. 133, 157 (2005) (SOUTER, J., dissenting) ("[I]t would be more than a stretch to say that the seriousness of the crime itself is affected by a defendant's subsequent experience"). And rather than inviting an open-ended review of mitigating factors that would include consideration of the defendant's possible future behavior in prison, the judge's answers emphasized the constraints on the "either/or" decision the jurors had to make.5 4 Skipper v. South Carolina, 476 U. S. 1, 4 (1986), recognized that a defendant's potential good behavior in the future would not relate to his "culpability for the crime he committed." Even the concurrence agreed: "Almost by definition," it reasoned, a prisoner's good behavior "neither excuses the defendant's crime nor reduces his responsibility for its commission." Id., at 12 (Powell, J., concurring in judgment). 5 When Juror Hailstone asked the judge about a particular piece of forward-looking evidence-the possibility that respondent would get psychiatric treatment in prison-the judge told the jury that it could not consider that evidence in making its decision. The judge's answer, while legally correct, lent further support to the conclusion that respondent's future conduct in a structured prison environment was not relevant because it did not fall within any of the listed factors. STEVENS, J., dissenting The arguments of counsel, the actual instructions to the jury, and this colloquy all support the conclusion that the jurors understood their task was to run through the listed statutory factors and weigh them against each other to determine whether respondent should be sentenced to death. Very little of respondent's evidence, however, even arguably "extenuate[d] the gravity of the crime." In my judgment, it is for that reason much more likely than not that the jury believed that the law forbade it from giving that evidence any weight at all. The Court of Appeals therefore correctly set aside respondent's death sentence. See Boyde v. California, 494 U. S. 370, 380 (1990) (plurality opinion) (requiring that a defendant show only that "there is a reasonable likelihood that the jury has applied the challenged instruction in a way that prevents the consideration of constitutionally relevant evidence"). VI Nothing in the Court's opinion in Boyde upsets my view that respondent's death sentence cannot stand. Over the dissent of four Justices, the Court in Boyde both adopted a new "legal standard for reviewing jury instructions claimed to restrict impermissibly a jury's consideration of relevant evidence," id., at 378, and approved a blatantly atextual interpretation of the unadorned factor (k) instruction, id., at 382, and n. 5. Applying its new standard and its dubious reading of factor (k), the Court held that there was "not a reasonable likelihood that Boyde's jurors interpreted the trial court's instructions to prevent consideration of mitigating evidence of background and character." Id., at 381. The Court rejected Boyde's argument that factor (k) made it impossible for the jury to consider testimony that Boyde had won a prize for dance choreography while in prison, which Boyde argued was Skipper-type evidence relating to whether "he could lead a useful life behind bars," 494 U. S., at 382, n. 5. But the Court did not hold or suggest that factor (k) allowed for the consideration of Skipper-type evi STEVENS, J., dissenting dence. Instead, the Court found that the evidence of his dance choreography talents was presented as part of his "overall strategy to portray himself as less culpable than other defendants due to his disadvantaged background and his character strengths," 494 U. S., at 382, n. 5 (emphasis added), and therefore fell within the ambit of factor (k). Thus, although the Boyde opinion does not state so explicitly, it assumes that the factor (k) instruction would not permit the jury to consider Skipper-type "evidence of postcrime good prison behavior to show that [a defendant] would not pose a danger to the prison community if sentenced to life imprisonment rather than death." 494 U. S., at 382, n. 5; see also Skipper, 476 U. S., at 4 (recognizing that inferences regarding a defendant's "probable future conduct if sentenced to life in prison . . . would not relate specifically to [the defendant's] culpability for the crime he committed"); Payton, 544 U. S., at 164 (SOUTER, J., dissenting) (“Boyde did not purport to hold that factor (k) naturally called for consideration of postcrime changes of fundamental views"). Here, respondent contends that there is a reasonable likelihood that the judge's instructions prevented the jury from considering precrime, forward-looking mitigation evidence regarding the possibility that he would lead a constructive life in a prison setting. Not only does the Court's opinion in Boyde fail to support the improbable argument that respondent's mitigating evidence falls within factor (k)'s purview, but its reasoning is entirely consistent with the Court of Appeals' contrary conclusion. Similarly, the Court's recent decision in Payton has little bearing here. In Payton, we granted certiorari to decide whether the Ninth Circuit's decision affirming the District Court's grant of habeas relief "was contrary to the limits on federal habeas review imposed by 28 U. S. C. § 2254(d)." 544 U. S., at 136. In concluding that it was, the Court relied heavily on the deferential standard of habeas review established by the Antiterrorism and Effective Death Penalty Act |