OCTOBER TERM, 2001

															ATKINS v. VIRGINIA

															CERTIORARI TO THE SUPREME COURT OF VIRGINIA No. 00-8452. Argued
February 20, 2002-Decided June 20, 2002

															JUSTICE STEVENS delivered the opinion of the Court.

															Those mentally retarded persons who meet the law's requirements
for criminal responsibility should be tried and

															punished when they commit crimes. Because of their disabilities
in areas of reasoning, judgment, and control of their impulses,
however, they do not act with the level of moral culpability that
characterizes the most serious adult criminal conduct. Moreover,
their impairments can jeopardize the [307] reliability and fairness of capital proceedings against mentally
retarded defendants. Presumably for these reasons, in the 13 years
since we decided Penry v. Lynaugh , 492 U. S. 302 (1989), the
American public, legislators, scholars, and judges have deliberated
over the question whether the death penalty should ever be imposed
on a mentally retarded criminal. The consensus reflected in those
deliberations informs our answer to the question presented by this
case: whether such executions are "cruel and unusual punishments"
prohibited by the Eighth Amendment to the Federal Constitution.

															I

															Petitioner, Daryl Renard Atkins, was convicted of abduction,
armed robbery, and capital murder, and sentenced to death. At
approximately midnight on August 16, 1996, Atkins and William
Jones, armed with a semiautomatic handgun, abducted Eric Nesbitt,
robbed him of the money on his person, drove him to an automated
teller machine in his pickup truck where cameras recorded their
withdrawal of additional cash, then took him to an isolated
location where he was shot eight times and killed.

															Jones and Atkins both testified in the guilt phase of Atkins'
trial.[ Footnote 1 ] Each confirmed most of the
details in the other's account of the incident, with the important
exception that each stated that the other had actually shot and
killed Nesbitt. Jones' testimony, which was both more coherent and
credible than Atkins', was obviously credited by the jury and was
sufficient to establish Atkins' guilt.[ Footnote
2 ] At the penalty [308] phase of the trial, the State introduced victim impact evidence
and proved two aggravating circumstances: future dangerousness and
"vileness of the offense." To prove future dangerousness, the State
relied on Atkins' prior felony convictions as well as the testimony
of four victims of earlier robberies and assaults. To prove the
second aggravator, the prosecution relied upon the trial record,
including pictures of the deceased's body and the autopsy
report.

															In the penalty phase, the defense relied on one witness, Dr.
Evan Nelson, a forensic psychologist who had evaluated Atkins
before trial and concluded that he was "mildly mentally
retarded."[ Footnote 3 ] His conclusion was based
on interviews with people who knew Atkins,[ Footnote
4 ] a review of school and court [309] records, and the administration of a standard intelligence test
which indicated that Atkins had a full scale IQ of 59.[ Footnote 5 ]

															The jury sentenced Atkins to death, but the Virginia Supreme
Court ordered a second sentencing hearing because the trial court
had used a misleading verdict form. 257 Va. 160,510 S. E. 2d 445
(1999). At the resentencing, Dr. Nelson again testified. The State
presented an expert rebuttal witness, Dr. Stanton Same now, who
expressed the opinion that Atkins was not mentally retarded, but
rather was of "average intelligence, at least," and diagnosable as
having antisocial personality disorder.[ Footnote
6 ] App.476. The jury again sentenced Atkins to death. [310] The Supreme Court of Virginia affirmed the imposition of the
death penalty. 260 Va. 375, 385, 534 S. E. 2d 312, 318 (2000).
Atkins did not argue before the Virginia Supreme Court that his
sentence was disproportionate to penalties imposed for similar
crimes in Virginia, but he did contend "that he is mentally
retarded and thus cannot be sentenced to death." Id. , at
386, 534 S. E. 2d, at 318. The majority of the state court rejected
this contention, relying on our holding in Penry. 260 Va.,
at 387, 534 S. E. 2d, at 319. The court was "not willing to commute
Atkins' sentence of death to life imprisonment merely because of
his IQ score." Id. , at 390, 534 S. E. 2d, at 321.

															Justice Hassell and Justice Koontz dissented. They rejected Dr.
Samenow's opinion that Atkins possesses average intelligence as
"incredulous as a matter of law," and concluded that "the
imposition of the sentence of death upon a criminal defendant who
has the mental age of a child between the ages of 9 and 12 is
excessive." Id. , at 394, 395-396, 534 S. E. 2d, at
323-324. In their opinion, "it is indefensible to conclude that
individuals who are mentally retarded are not to some degree less
culpable for their criminal acts. By definition, such individuals
have substantial limitations not shared by the general population.
A moral and civilized society diminishes itself if its system of
justice does not afford recognition and consideration of those
limitations in a meaningful way." Id. , at 397, 534 S. E.
2d, at 325.

															Because of the gravity of the concerns expressed by the
dissenters, and in light of the dramatic shift in the state
legislative landscape that has occurred in the past 13 years, we
granted certiorari to revisit the issue that we first addressed in
the Penry case. 533 U. S. 976 (2001). [311] II

															The Eighth Amendment succinctly prohibits "[e]xcessive"
sanctions. It provides: "Excessive bail shall not be required, nor
excessive fines imposed, nor cruel and unusual punishments
inflicted." In Weems v. United States , 217 U. S. 349 (1910), we
held that a punishment of 12 years jailed in irons at hard and
painful labor for the crime of falsifying records was excessive. We
explained "that it is a precept of justice that punishment for
crime should be graduated and proportioned to [the] offense." Id. , at 367. We have repeatedly applied this
proportionality precept in later cases interpreting the Eighth
Amendment. See Harmelin v. Michigan , 501 U. S. 957 , 997-998
(1991) (KENNEDY, J., concurring in part and concurring in
judgment); see also id. , at 1009-1011 (White, J.,
dissenting).[ Footnote 7 ] Thus, even though
"imprisonment for ninety days is not, in the abstract, a punishment
which is either cruel or unusual," it may not be imposed as a
penalty for "the 'status' of narcotic addiction," Robinson v.
California , 370
U. S. 660 , 666-667 (1962), because such a sanction would be
excessive. As Justice Stewart explained in Robinson: "Even
one day in prison would be a cruel and unusual punishment for the
'crime' of having a common cold." Id. , at 667.

															A claim that punishment is excessive is judged not by the
standards that prevailed in 1685 when Lord Jeffreys presided over
the "Bloody Assizes" or when the Bill of Rights was adopted, but
rather by those that currently prevail. As Chief Justice Warren
explained in his opinion in Trop v. Dulles , 356 U. S. 86 (1958): "The
basic concept underlying the Eighth Amendment is nothing less than
the dignity of man . . . . The Amendment must draw its meaning from
the [312] evolving standards of decency that mark the progress of a
maturing society." Id. , at 100-101.

															Proportionality review under those evolving standards should be
informed by "'objective factors to the maximum possible extent,'"
see Harmelin , 501 U. S., at 1000 (quoting Rummel v.
Estelle , 445 U.
S. 263 , 274-275 (1980)). We have pinpointed that the "clearest
and most reliable objective evidence of contemporary values is the
legislation enacted by the country's legislatures." Penry ,
492 U. S., at 331. Relying in part on such legislative evidence, we
have held that death is an impermissibly excessive punishment for
the rape of an adult woman, Coker v. Georgia , 433 U. S. 584 , 593-596
(1977), or for a defendant who neither took life, attempted to take
life, nor intended to take life, Enmund v. Florida, 458 U.
S. 782, 789-793 (1982). In Coker , we focused primarily on
the then-recent legislation that had been enacted in response to
our decision 10 years earlier in Furman v. Georgia , 408 U. S. 238 (1972) (per curiam) , to support the conclusion that the
"current judgment," though "not wholly unanimous," weighed very
heavily on the side of rejecting capital punishment as a "suitable
penalty for raping an adult woman." Coker , 433 U. S., at
596. The "current legislative judgment" relevant to our decision in Enmund was less clear than in Coker but
"nevertheless weigh[ed] on the side of rejecting capital punishment
for the crime at issue." Enmund , 458 U. S., at 793.

															We also acknowledged in Coker that the objective
evidence, though of great importance, did not "wholly determine"
the controversy, "for the Constitution contemplates that in the end
our own judgment will be brought to bear on the question of the
acceptability of the death penalty under the Eighth Amendment." 433
U. S., at 597. For example, in Enmund , we concluded by
expressing our own judgment about the issue: "For purposes of imposing the death penalty, Enmund's criminal culpability must be limited to his participation [313] in the robbery, and his punishment must be tailored to his
personal responsibility and moral guilt. Putting Enmund to death to
avenge two killings that he did not commit and had no intention of
committing or causing does not measurably contribute to the
retributive end of ensuring that the criminal gets his just
deserts. This is the judgment of most of the legislatures that
have recently addressed the matter, and we have no reason to
disagree with that judgment for purposes of construing and
applying the Eighth Amendment." 458 U. S., at 801 (emphasis
added). Thus, in cases involving a consensus, our own judgment is
"brought to bear," Coker , 433 U. S., at 597, by asking
whether there is reason to disagree with the judgment reached by
the citizenry and its legislators.

															Guided by our approach in these cases, we shall first review the
judgment of legislatures that have addressed the suitability of
imposing the death penalty on the mentally retarded and then
consider reasons for agreeing or disagreeing with their
judgment.

															III

															The parties have not called our attention to any state
legislative consideration of the suitability of imposing the death
penalty on mentally retarded offenders prior to 1986. In that year,
the public reaction to the execution of a mentally retarded
murderer in Georgia[ Footnote 8 ] apparently led to
the enact- [314] ment of the first state statute prohibiting such
executions.[ Footnote 9 ] In 1988, when Congress
enacted legislation reinstating the federal death penalty, it
expressly provided that a "sentence of death shall not be carried
out upon a person who is mentally retarded."[ Footnote 10 ] In 1989, Maryland enacted a similar
prohibition.[ Footnote 11 ] It was in that year
that we decided Penry , and concluded that those two state
enactments, "even when added to the 14 States that have rejected
capital punishment completely, do not provide sufficient evidence
at present of a national consensus." 492 U. S., at 334.

															Much has changed since then. Responding to the national
attention received by the Bowden execution and our decision in Penry , state legislatures across the country began to
address the issue. In 1990, Kentucky and Tennessee enacted statutes
similar to those in Georgia and Maryland, as did New Mexico in
1991, and Arkansas, Colorado, Washington, Indiana, and Kansas in
1993 and 1994.[ Footnote 12 ] In 1995, when New
York reinstated its death penalty, it emulated the Federal
Government by expressly exempting the mentally retarded.[ Footnote 13 ] Nebraska followed suit in 1998.[ Footnote 14 ] There appear [315] to have been no similar enactments during the next two years,
but in 2000 and 2001 six more States--South Dakota, Arizona,
Connecticut, Florida, Missouri, and North Carolina--joined the
procession.[ Footnote 15 ] The Texas Legislature
unanimously adopted a similar bill,[ Footnote 16 ]
and bills have passed at least one house in other States, including
Virginia and Nevada.[ Footnote 17 ]

															It is not so much the number of these States that is
significant, but the consistency of the direction of
change.[ Footnote 18 ] Given the well-known fact
that anticrime legislation is far more popular than legislation
providing protections for persons guilty of violent crime, the
large number of States prohibiting the execution of mentally
retarded persons (and the [316] complete absence of States passing legislation reinstating the
power to conduct such executions) provides powerful evidence that
today our society views mentally retarded offenders as
categorically less culpable than the average criminal. The evidence
carries even greater force when it is noted that the legislatures
that have addressed the issue have voted overwhelmingly in favor of
the prohibition.[ Footnote 19 ] Moreover, even in
those States that allow the execution of mentally retarded
offenders, the practice is uncommon. Some States, for example New
Hampshire and New Jersey, continue to authorize executions, but
none have been carried out in decades. Thus there is little need to
pursue legislation barring the execution of the mentally retarded
in those States. And it appears that even among those States that
regularly execute offenders and that have no prohibition with
regard to the mentally retarded, only five have executed offenders
possessing a known IQ less than 70 since we decided Penry .[ Footnote 20 ] The practice,
therefore, has become truly unusual, and it is fair to say that a
national consensus has developed against it.[ Footnote 21 ] [317] To the extent there is serious disagreement about the execution
of mentally retarded offenders, it is in determining which
offenders are in fact retarded. In this case, for instance, the
Commonwealth of Virginia disputes that Atkins suffers from mental
retardation. Not all people who claim to be mentally retarded will
be so impaired as to fall within the range of mentally retarded
offenders about whom there is a national consensus. As was our
approach in Ford v. Wainwright , 477 U. S. 399 (1986),
with regard to insanity, "we leave to the State[s] the task of
developing appropriate ways to enforce the constitutional
restriction upon [their] execution of sentences." Id. , at
405, 416-417.[ Footnote 22 ]

															IV

															This consensus unquestionably reflects widespread judgment about
the relative culpability of mentally retarded offenders, and the
relationship between mental retardation and the penological
purposes served by the death penalty. Additionally, it suggests
that some characteristics of mental retardation undermine the
strength of the procedural protections that our capital
jurisprudence steadfastly guards. [318] As discussed above, clinical definitions of mental retardation
require not only subaverage intellectual functioning, but also
significant limitations in adaptive skills such as communication,
self-care, and self-direction that became manifest before age 18.
Mentally retarded persons frequently know the difference between
right and wrong and are competent to stand trial. Because of their
impairments, however, by definition they have diminished capacities
to understand and process information, to communicate, to abstract
from mistakes and learn from experience, to engage in logical
reasoning, to control impulses, and to understand the reactions of
others.[ Footnote 23 ] There is no evidence that
they are more likely to engage in criminal conduct than others, but
there is abundant evidence that they often act on impulse rather
than pursuant to a premeditated plan, and that in group settings
they are followers rather than leaders.[ Footnote
24 ] Their deficiencies do not warrant an exemption from
criminal sanctions, but they do diminish their personal
culpability.

															In light of these deficiencies, our death penalty jurisprudence
provides two reasons consistent with the legislative consensus that
the mentally retarded should be categorically excluded from
execution. First, there is a serious question as to whether either
justification that we have recognized as [319] a basis for the death penalty applies to mentally retarded
offenders. Gregg v. Georgia , 428 U. S. 153 , 183 (1976)
(joint opinion of Stewart, Powell, and STEVENS, JJ.), identified
"retribution and deterrence of capital crimes by prospective
offenders" as the social purposes served by the death penalty.
Unless the imposition of the death penalty on a mentally retarded
person "measurably contributes to one or both of these goals, it
'is nothing more than the purposeless and needless imposition of
pain and suffering,' and hence an unconstitutional punishment." Enmund , 458 U. S., at 798.

															With respect to retribution--the interest in seeing that the
offender gets his "just deserts"--the severity of the appropriate
punishment necessarily depends on the culpability of the offender.
Since Gregg , our jurisprudence has consistently confined
the imposition of the death penalty to a narrow category of the
most serious crimes. For example, in Godfrey v. Georgia , 446 U. S. 420 (1980), we set aside a death sentence because the petitioner's
crimes did not reflect "a consciousness materially more 'depraved'
than that of any person guilty of murder." Id. , at 433. 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. Thus, pursuant to our narrowing
jurisprudence, which seeks to ensure that only the most deserving
of execution are put to death, an exclusion for the mentally
retarded is appropriate.

															With respect to deterrence--the interest in preventing capital
crimes by prospective offenders--"it seems likely that 'capital
punishment can serve as a deterrent only when murder is the result
of premeditation and deliberation,'" En mund , 458
U. S., at 799. Exempting the mentally retarded from that punishment
will not affect the "cold calculus that precedes the decision" of
other potential murderers. Gregg , 428 U. S., at 186.
Indeed, that sort of calculus is at the opposite end of the
spectrum from behavior of mentally retarded [320] offenders. The theory of deterrence in capital sentencing is
predicated upon the notion that the increased severity of the
punishment will inhibit criminal actors from carrying out murderous
conduct. Yet it is the same cognitive and behavioral impairments
that make these defendants less morally culpable--for example, the
diminished ability to understand and process information, to learn
from experience, to engage in logical reasoning, or to control
impulses--that also make 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. Nor will
exempting the mentally retarded from execution lessen the deterrent
effect of the death penalty with respect to offenders who are not
mentally retarded. Such individuals are unprotected by the
exemption and will continue to face the threat of execution. Thus,
executing the mentally retarded will not measurably further the
goal of deterrence.

															The reduced capacity of mentally retarded offenders provides a
second justification for a categorical rule making such offenders
ineligible for the death penalty. The risk "that the death penalty
will be imposed in spite of factors which may call for a less
severe penalty," Lockett v. Ohio , 438 U. S. 586 , 605
(1978), is enhanced, not only by the possibility of false
confessions,[ Footnote 25 ] but also by the lesser
ability of mentally retarded defendants to make a persuasive
showing of mitigation in the face of prosecutorial evidence of one
or more aggravating factors. Mentally retarded defendants may be
less able to give meaningful assistance to their counsel and [321] are typically poor witnesses, and their demeanor may create an
unwarranted impression of lack of remorse for their crimes. As Penry demonstrated, moreover, reliance on mental
retardation as a mitigating factor can be a two-edged sword that
may enhance the likelihood that the aggravating factor of future
dangerousness will be found by the jury. 492 U. S., at 323-325.
Mentally retarded defendants in the aggregate face a special risk
of wrongful execution.

															Our independent evaluation of the issue reveals no reason to
disagree with the judgment of "the legislatures that have recently
addressed the matter" and concluded that death is not a suitable
punishment for a mentally retarded criminal. We are not persuaded
that the execution of mentally retarded criminals will measurably
advance the deterrent or the retributive purpose of the death
penalty. Construing and applying the Eighth Amendment in the light
of our "evolving standards of decency," we therefore conclude that
such punishment is excessive and that the Constitution "places a
substantive restriction on the State's power to take the life" of a
mentally retarded offender. Ford , 477 U. S., at 405.

															The judgment of the Virginia Supreme Court is reversed, and the
case is remanded for further proceedings not inconsistent with this
opinion.

															It is so ordered.

															CHIEF JUSTICE REHNQUIST, with whom JUSTICE SCALIA and JUSTICE
THOMAS join, dissenting.

															The question presented by this case is whether a national
consensus deprives Virginia of the constitutional power to impose
the death penalty on capital murder defendants like petitioner, i. e. , those defendants who indisputably are competent to
stand trial, aware of the punishment they are about to suffer and
why, and whose mental retardation has been found an insufficiently
compelling reason to lessen their individual responsibility for the
crime. The Court pronounces [322] the punishment cruel and unusual primarily because 18 States
recently have passed laws limiting the death eligibility of certain
defendants based on mental retardation alone, despite the fact that
the laws of 19 other States besides Virginia continue to leave the
question of proper punishment to the individuated consideration of
sentencing judges or juries familiar with the particular offender
and his or her crime. See ante , at 314-315.

															I agree with JUSTICE SCALIA, post , at 337-338
(dissenting opinion), that the Court's assessment of the current
legislative judgment regarding the execution of defendants like
petitioner more resembles a post hoc rationalization for
the majority's subjectively preferred result rather than any
objective effort to ascertain the content of an evolving standard
of decency. I write separately, however, to call attention to the
defects in the Court's decision to place weight on foreign laws,
the views of professional and religious organizations, and opinion
polls in reaching its conclusion. See ante , at 316-317, n.
21. The Court's suggestion that these sources are relevant to the
constitutional question finds little support in our precedents and,
in my view, is antithetical to considerations of federalism, which
instruct that any "permanent prohibition upon all units of
democratic government must [be apparent] in the operative acts
(laws and the application of laws) that the people have approved." Stanford v. Ken tucky , 492 U. S. 361 , 377 (1989)
(plurality opinion). The Court's uncritical acceptance of the
opinion poll data brought to our attention, moreover, warrants
additional comment, because we lack sufficient information to
conclude that the surveys were conducted in accordance with
generally accepted scientific principles or are capable of
supporting valid empirical inferences about the issue before
us.

															In making determinations about whether a punishment is "cruel
and unusual" under the evolving standards of decency embraced by
the Eighth Amendment, we have emphasized that legislation is the
"clearest and most reliable objective [323] evidence of contemporary values." Penry v. Lynaugh, 492 U. S. 302, 331 (1989). See also McCleskey v. Kemp , 481 U. S. 279 ,
300 (1987). The reason we ascribe primacy to legislative enactments
follows from the constitutional role legislatures play in
expressing policy of a State. "'[I]n a democratic society
legislatures, not courts, are constituted to respond to the will
and consequently the moral values of the people.' " Gregg v.
Georgia , 428 U.
S. 153 , 175-176 (1976) (joint opinion of Stewart, Powell, and
STEVENS, JJ.) (quoting Furman v. Georgia , 408 U. S. 238 , 383 (1972)
(Burger, C. J., dissenting)). And because the specifications of
punishments are "peculiarly questions of legislative policy," Gore v. United States , 357 U. S. 386 , 393
(1958), our cases have cautioned against using" 'the aegis of the
Cruel and Unusual Punishment Clause'" to cut off the normal
democratic processes, Gregg, supra , at 176 (quoting Powell v. Texas , 392 U. S. 514 , 533 (1968)
(plurality opinion)).

															Our opinions have also recognized that data concerning the
actions of sentencing juries, though entitled to less weight than
legislative judgments, "'is a significant and reliable objective
index of contemporary values,'" Coker v. Georgia , 433 U. S. 584 , 596 (1977)
(plurality opinion) (quoting Gregg, supra , at 181),
because of the jury's intimate involvement in the case and its
function of "'maintain[ing] a link between contemporary community
values and the penal system,'" Gregg, supra , at 181
(quoting Witherspoon v. Illinois , 391 U. S. 510 , 519, n. 15
(1968)). In Coker, supra , at 596-597, for example, we
credited data showing that "at least 9 out of 10" juries in Georgia
did not impose the death sentence for rape convictions. And in Enmund v. Florida , 458 U. S. 782 , 793-794
(1982), where evidence of the current legislative judgment was not
as "compelling" as that in Coker (but more so than that
here), we were persuaded by "overwhelming [evidence] that American
juries . . . repudiated imposition of the death penalty" for a
defendant who neither took life nor attempted or intended to take
life. [324] In my view, these two sources--the work product of legislatures
and sentencing jury determinations--ought to be the sole indicators
by which courts ascertain the contemporary American conceptions of
decency for purposes of the Eighth Amendment. They are the only
objective indicia of contemporary values firmly supported by our
precedents. More importantly, however, they can be reconciled with
the undeniable precepts that the democratic branches of government
and individual sentencing juries are, by design, better suited than
courts to evaluating and giving effect to the complex societal and
moral considerations that inform the selection of publicly
acceptable criminal punishments.

															In reaching its conclusion today, the Court does not take notice
of the fact that neither petitioner nor his amici have
adduced any comprehensive statistics that would conclusively prove
(or disprove) whether juries routinely consider death a
disproportionate punishment for mentally retarded offenders like
petitioner.[ Footnote * ] Instead, it adverts to
the fact that other countries have disapproved imposition of the
death penalty for crimes committed by mentally retarded offenders,
see ante , at 316-317, n. 21 (citing the Brief for European
Union as Amicus Curiae 2). I fail to see, how- [325] ever, how the views of other countries regarding the punishment
of their citizens provide any support for the Court's ultimate
determination. While it is true that some of our prior opinions
have looked to "the climate of international opinion," Coker,
supra , at 596, n. 10, to reinforce a conclusion regarding
evolving standards of decency, see Thompson v. Oklahoma , 487 U. S. 815 ,
830 (1988) (plurality opinion); Enmund, supra , at 796-797,
n. 22; Trop v. Dulles , 356 U. S. 86 , 102-103
(1958) (plurality opinion); we have since explicitly rejected the
idea that the sentencing practices of other countries could "serve
to establish the first Eighth Amendment prerequisite, that [a]
practice is accepted among our people." Stanford , 492 U.
S., at 369, n. 1 (emphasizing that "American conceptions
of decency . . . are dispositive" (emphasis in original)). Stanford's reasoning makes perfectly good sense, and
the Court offers no basis to question it. For if it is evidence of
a national consensus for which we are looking, then the
viewpoints of other countries simply are not relevant. And nothing
in Thompson, Enmund, Coker , or Trop suggests
otherwise. Thompson, Enmund , and Coker rely only
on the bare citation of international laws by the Trop plurality as authority to deem other countries' sentencing choices
germane. But the Trop plurality--representing the view of
only a minority of the Court--offered no explanation for its own
citation, and there is no reason to resurrect this view given our
sound rejection of the argument in Stanford. To further buttress its appraisal of contemporary societal
values, the Court marshals public opinion poll results and evidence
that several professional organizations and religious groups have
adopted official positions opposing the imposition of the death
penalty upon mentally retarded offenders. See ante , at
316-317, n. 21 (citing Brief for American Psychological Association
et al. as Amici Curiae; Brief for American Association on
Mental Retardation et al. as Amici Curiae; noting that
"representatives of widely diverse reli- [326] gious communities . . . reflecting Christian, Jewish, Muslim,
and Buddhist traditions . . . 'share a conviction that the
execution of persons with mental retardation cannot be morally
justified' "; and stating that "polling data shows a widespread
consensus among Americans . . . that executing the mentally
retarded is wrong"). In my view, none should be accorded any weight
on the Eighth Amendment scale when the elected representatives of a
State's populace have not deemed them persuasive enough to prompt
legislative action. In Penry , 492 U. S., at 334-335, we
were cited similar data and declined to take them into
consideration where the "public sentiment expressed in [them]" had
yet to find expression in state law. See also Stanford ,
492 U. S., at 377 (plurality opinion) (refusing "the invitation to
rest constitutional law upon such uncertain foundations" as "public
opinion polls, the views of interest groups, and the positions
adopted by various professional associations"). For the Court to
rely on such data today serves only to illustrate its willingness
to proscribe by judicial fiat--at the behest of private
organizations speaking only for themselves--a punishment about
which no across-the-board consensus has developed through the
workings of normal democratic processes in the laboratories of the
States.

															Even if I were to accept the legitimacy of the Court's decision
to reach beyond the product of legislatures and practices of
sentencing juries to discern a national standard of decency, I
would take issue with the blind-faith credence it accords the
opinion polls brought to our attention. An extensive body of social
science literature describes how methodological and other errors
can affect the reliability and validity of estimates about the
opinions and attitudes of a population derived from various
sampling techniques. Everything from variations in the survey
methodology, such as the choice of the target population, the
sampling design used, the questions asked, and the statistical
analyses used to interpret the data can skew the results. See, e. g. , R. Groves, Survey [327] Errors and Survey Costs (1989); 1 C. Turner & E. Martin,
Surveying Subjective Phenomena (1984).

															The Federal Judicial Center's Reference Manual on Scientific
Evidence 221-271 (1994) and its Manual for Complex Litigation
21.493, pp. 101-103 (3d ed. 1995), offer helpful suggestions to
judges called upon to assess the weight and admissibility of survey
evidence on a factual issue before a court. Looking at the polling
data (reproduced in the Appendix to this opinion) in light of these
factors, one cannot help but observe how unlikely it is that the
data could support a valid inference about the question presented
by this case. For example, the questions reported to have been
asked in the various polls do not appear designed to gauge whether
the respondents might find the death penalty an acceptable
punishment for mentally retarded offenders in rare cases. Most are
categorical (e. g. , "Do you think that persons convicted
of murder who are mentally retarded should or should not receive
the death penalty?"), and, as such, would not elicit whether the
respondent might agree or disagree that all mentally retarded
people by definition can never act with the level of culpability
associated with the death penalty, regardless of the severity of
their impairment or the individual circumstances of their crime.
Second, none of the 27 polls cited disclose the targeted survey
population or the sampling techniques used by those who conducted
the research. Thus, even if one accepts that the survey instruments
were adequately designed to address a relevant question, it is
impossible to know whether the sample was representative enough or
the methodology sufficiently sound to tell us anything about the
opinions of the citizens of a particular State or the American
public at large. Finally, the information provided to us does not
indicate why a particular survey was conducted or, in a few cases,
by whom, factors which also can bear on the objectivity of the
results. In order to be credited here, such surveys should be
offered as [328] Appendix to opinion of REHNQUIST, C. J.

															evidence at trial, where their sponsors can be examined and
cross-examined about these matters.

															***

															There are strong reasons for limiting our inquiry into what
constitutes an evolving standard of decency under the Eighth
Amendment to the laws passed by legislatures and the practices of
sentencing juries in America. Here, the Court goes beyond these
well-established objective indicators of contemporary values. It
finds "further support to [its] conclusion" that a national
consensus has developed against imposing the death penalty on all
mentally retarded defendants in international opinion, the views of
professional and religious organizations, and opinion polls not
demonstrated to be reliable. Ante , at 317, n. 21.
Believing this view to be seriously mistaken, I dissent. APPENDIX TO OPINION OF REHNQUIST, C. J. Poll and survey results reported in Brief for American
Association on Mental Retardation et al. as Amici Curiae 3a-7a, and cited by the Court, ante , at 317, n. 21: STATE POLL DATE RESPONSE QUESTION AR Arkansans? Opinion on the Death Penalty, Opinion Research
Associates, Inc., Q. 13 (July 1992) John DiPippa, Will Fairchild s
Death Violate the Constitution, or Simply Our Morality?, Arkansas
Forum, Sept. 1993 1992 61% never appropriate 17% is appropriate 5% opposed to all
executions 17% undecided "Some people say that there is nothing wrong with executing a
person who is mentally retarded. Others say that the death penalty
should never be imposed on a person who is mentally retarded. Which
of these positions comes closest to your own" [329] Appendix to opinion of Rehnquist, C. J. STATE POLL DATE RESPONSE QUESTION AZ Behavior Research Center, Survey 2000, Q. 3 (July 2000) 2000 71% oppose 12% favor 11% depends 6% ref/unsure "For persons convicted of murder, do you favor or oppose use of
the death penalty when the defendant is mentally retarded" CA Field Research Corp., California Death Penalty Survey, Q. 22
(Dec. 1989) Frank Hill, Death Penalty For The Retarded, San Diego
Union-Tribune, Mar. 28, 1993, at G3 1989 64.8% not all right 25.7% is all right 9.5% no opinion "Some people feel there is nothing wrong with imposing the
death penalty on persons who are mentally retarded depending on the
circum- stances. Others feel the death penalty should never be
imposed on persons who are mentally retarded under any
circumstance. The death penalty on a mentally retarded person is .
. . " CA Field Research Corp., California Death Penalty Survey, Q. 62D
(Feb. 1997) Paul Van Slambrouck, Execution and a Convict's Mental
State, The Christian Science Monitor, Apr. 27, 1998, at 1 1997 74% disagree 17% agree 9% no opinion "Mentally retarded defendants should be given the death penalty
when they commit capital crimes." CT Quinnipac University 2001 77% no 12% yes "Do you think that persons convicted of [330] Appendix to opinion of REHNQUIST, C. J. STATE POLL DATE RESPONSE QUESTION Polling Institute, Death Penalty Survey Info., Q. 35 (Apr. 23,
2001) 11% don't know murder who are mentally retarded should or should not receive
the death penalty?" FL Amnesty International Martin Dyckman, Death Penalty's High
Price, St. Petersburg Times, Apr. 19, 1992, at 3D 1986 71% opposed [not provided] GA Georgia State University Tracy Thompson, Executions of Retarded
Opposed, Atlanta Journal, Jan. 6, 1987, at 1B 1987 66% opposed 17% favor 16% depends [not provided] LA Marketing Research Inst., Loyola Death Penalty Survey, Q. 7
(Feb. 1993) 1993 77.7% no 9.2% yes 13% uncertain "Would you vote for the death penalty if the convicted person
is mentally retarded?" LA Louisiana Poll, Poll 104, Q. 9 (Apr. 2001) 2001 68% no 19% yes 11% no opinion 2% won t say "Do you believe mentally retarded people, who are convicted of
capital murder, should be executed?" MD Survey Research Center, University of Maryland (Nov. 1988) 1988 82% opposed 8% favor 10% other "Would you favor or oppose the death penalty for a person
convicted of murder if he or she is mentally retarded?" [331] Appendix to opinion of Rehnquist, C. J. STATE POLL DATE RESPONSE QUESTION MO Missouri Mental Retardation and Death Penalty Survey, Q. 5
(Oct. 1993) 1993 61.3% not all right 23.7% is all right 15% don't know "Some people feel there is nothing wrong with imposing the
death penalty on persons who are mentally retarded depending on the
circum- stances. Others feel that the death penalty should never be
imposed on persons who are mentally retarded under any circum-
stances. Do you think it IS or IS NOT all right to impose the death
penalty on a mentally retarded person?" NC/SC Charlotte Observer- WMTV News Poll (Sept. 2000) Diane Suchetka,
Carolinas Join Emotional Debate Over Executing Mentally Retarded,
Charlotte Observer, Sept. 13, 2000 2000 64% yes 21% no 14% not sure "Should the Carolinas ban the execution of people with mental
retardation?" NM Research & Polling Inc., Use of the Death Penalty Public
Opinion Poll, Q. 2 (Dec. 1990) 1990 57.1% oppose 10.5% support 26.2% depends 6.1% don't know 62% support the death penalty. Asked of those that support it,
"for which of the following do you support use of the [332] Appendix to opinion of REHNQUIST, C. J. STATE POLL DATE RESPONSE QUESTION death penalty . . . when the convicted person is mentally
retarded?" NY Patrick Caddell Enterprises, NY Public Opinion Poll, The Death
Penalty: An Executive Summary, Q. 27 (May 1989) Ronald Tabak &
J. Mark Lane, The Execution of Injustice: A Cost and
Lack-of-Benefit Analysis of the Death Penalty, 23 Loyola (LA) L.
Rev. 59, 93 (1989) 1989 82% oppose 10% favor 9% don't know "I'd like you to imagine you are a member of a jury. The jury
has found the defendant guilty of murder beyond a reasonable doubt
and now needs to decide about sentencing. You are the last juror to
decide and your decision will determine whether or not the offender
will receive the death penalty. Would you favor or oppose
sentencing the offender to the death penalty if . . . the convicted
person were mentally retarded?" OK Survey of Oklahoma Attitudes Regarding Capital Punishment:
Survey Conducted for Oklahoma Indigent Defense System, Q. C (July
1999) 1999 83.5% should not be executed 10.8% should be executed 5.7%
depends "Some people think that persons convicted of murder who are
mentally retarded (or have a mental age of between 5 and 10 years)
should not be executed. Other people think that 'retarded' persons
should be subject to the death penalty like anyone else. Which is
closer to [333] STATE POLL DATE RESPONSE QUESTION the way you feel, that 'retarded' persons should not be
executed, or that 'retarded' persons should be subject to the death
penalty like everyone else?" TX Austin American Statesman, Nov. 15, 1988, at B3 1988 73% opposed [not provided] TX Sam Houston State University, College of Criminal Justice,
Texas Crime Poll On-line (1995) Domingo Ramirez, Jr., Murder Trial
May Hinge on Defendant's IQ, The Fort Worth Star-Telegram, Oct. 6,
1997, at 1 1995 61% more likely to oppose "For each of the following items that have been found to affect
people's attitude about the death penalty, please state if you
would be more likely to favor or more likely to oppose the death
penalty, or wouldn't it matter . . . if the murderer is severely
mentally retarded?" TX Scripps-Howard Texas Poll: Death Penalty (Mar. 2001) Dan
Parker, Most Texans Support Death Penalty, Corpus Christi
Caller-Times, Mar. 2, 2001, at A1 2001 66% no 17% yes 17% don't know/no answer "Should the state use the death penalty when the inmate is
considered mentally retarded?" [334] Appendix to opinion of REHNQUIST, C. J. STATE POLL DATE RESPONSE QUESTION TX Houston Chronicle (Feb. 2001) Stephen Brewer & Mike Tolson,
A Deadly Distinction: Part III, Debate Fervent in Mental Cases,
Johnny Paul Penry Illustrates a Lingering Capital Conundrum, The
Houston Chronicle, Feb. 6, 2001, at A6 2001 59.9% no support 19.3% support 20.7% not sure/ no answer "Would you support the death penalty if you were convinced the
defendant were guilty, but the defendant is mentally
impaired?" US Harris Poll, Unfinished Agenda on Race, Q. 32 (Sept. 1988)
Saundra Torry, High Court to Hear Case on Retarded Slayer, The
Washington Post, Jan. 11, 1989, at A6 1988 71% should not be executed 21% should be executed 4% depends 3%
not sure/ refused "Some people think that persons convicted of murder who have a
mental age of less than 18 (or the 'retarded') should not be
executed. Other people think that 'retarded' persons should be
subject to the death penalty like anyone else. Which is closer to
the way you feel, that 'retarded' persons should not be executed,
or that 'retarded' persons should be subject to the death penalty
like anyone else?" [335] Appendix to opinion of Rehnquist, C. J. STATE POLL DATE RESPONSE QUESTION US Yankelovich Clancy Shulman, Time/CNN Poll, Q. 14 (July 7, 1989)
Samuel R. Gross, Second Thoughts: Americans' Views on the Death
Penalty at the Turn of the Century, Capital Punishment and the
American Future (Feb. 2001) 1989 61% oppose 27% favor 12% not sure "Do you favor or oppose the death penalty for mentally retarded
individuals convicted of serious crimes, such as murder?" US The Tarrance Group, Death Penalty Poll, Q. 9 (Mar. 1993) Samuel
R. Gross, Update: American Public Opinion on the Death
Penalty--It's Getting Personal, 83 Cornell L. Rev. 1448, 1467
(1998) 1993 56% not all right 32% is all right 11% unsure "Some people feel that there is nothing wrong with imposing the
death penalty on persons who are mentally retarded, depending on
the circumstances. Others feel that the death penalty should never
be imposed on persons who are mentally retarded under any
circumstances. Which of these views comes closest to your
own?" US Public Policy Research, Crime in America, Q. 72 (July
1995) 1995 67% likely to oppose 7% likely to favor 26% wouldn't
matter "For each item please tell me if you would be more likely to
favor the death penalty, more likely to oppose the death [336] Appendix to opinion of REHNQUIST, C. J. STATE POLL DATE RESPONSE QUESTION penalty or it wouldn't matter . . . if it is true that the
murderer is severely mentally retarded?" US Princeton Research, Newsweek Poll, Q. 16 (Nov. 1995) Samuel R.
Gross, Update: American Public Opinion on the Death Penalty--It's
Getting Personal, 83 Cornell L. Rev. 1448, 1468 (1998) 1995 83% oppose 9% favor 8% don't know refused "If the convicted person was . . . mentally retarded, would you
favor or oppose the death penalty?" US Peter Hart Research Associates, Inc., Innocence Survey, Q. 12
(Dec. 1999) 1999 58% strongly/ somewhat favor 26% strongly/ somewhat oppose 12%
mixed/ neutral 4% not sure ". . . [F]or each proposal I read, please tell me whether you
strongly favor, somewhat favor, have mixed or neutral feelings,
somewhat oppose, or strongly oppose that proposal . . . .
[P]rohibit the death penalty for defendants who are mentally
retarded." US Peter Hart Research Associates, Inc., Innocence Survey, Q. 9
(Dec. 1999) 1999 72% much/ somewhat less likely 19% no difference 9% not sure
47% much less likely Suppose you were on a jury and a defendant was convicted of
murder. Now it is time to determine the sentence. If you knew that
the [337] STATE POLL DATE RESPONSE QUESTION 25% somewhat less likely defendant was mentally retarded or otherwise mentally impaired
in a serious way, would you be much less likely to support the use
of the death penalty in this specific case, somewhat less likely,
or would it make no difference to you?" US Houston Chronicle (Feb. 2001) Stephen Brewer & Mike Tolson,
A Deadly Distinction: Part III, Debate Fervent in Mental Cases,
Johnny Paul Penry Illustrates a Lingering Capital Conundrum, The
Houston Chronicle, Feb. 6, 2001, at A6 2001 63.8% no support 16.4% support 19.8% not sure/ no answer "Would you support the death penalty if you were convinced the
defendant were guilty, but the defendant is mentally
impaired?" JUSTICE SCALIA, with whom THE CHIEF JUSTICE and JUSTICE THOMAS
join, dissenting.

															Today's decision is the pinnacle of our Eighth Amendment
death-is-different jurisprudence. Not only does it, like all of
that jurisprudence, find no support in the text or history of the
Eighth Amendment; it does not even have support in current social
attitudes regarding the conditions that render [338] an otherwise just death penalty inappropriate. Seldom has an
opinion of this Court rested so obviously upon nothing but the
personal views of its Members.

															I

															I begin with a brief restatement of facts that are abridged by
the Court but important to understanding this case. After spending
the day drinking alcohol and smoking marijuana, petitioner Daryl
Renard Atkins and a partner in crime drove to a convenience store,
intending to rob a customer. Their victim was Eric Nesbitt, an
airman from Langley Air Force Base, whom they abducted, drove to a
nearby automated teller machine, and forced to withdraw $200. They
then drove him to a deserted area, ignoring his pleas to leave him
unharmed. According to the co-conspirator, whose testimony the jury
evidently credited, Atkins ordered Nesbitt out of the vehicle and,
after he had taken only a few steps, shot him one, two, three,
four, five, six, seven, eight times in the thorax, chest, abdomen,
arms, and legs.

															The jury convicted Atkins of capital murder. At resentencing
(the Virginia Supreme Court affirmed his conviction but remanded
for resentencing because the trial court had used an improper
verdict form, 257 Va. 160, 179,510 S. E. 2d 445, 457 (1999)), the
jury heard extensive evidence of petitioner's alleged mental
retardation. A psychologist testified that petitioner was mildly
mentally retarded with an IQ of 59, that he was a "slow learner,"
App. 444, who showed a "lack of success in pretty much every domain
of his life," id. , at 442, and that he had an "impaired"
capacity to appreciate the criminality of his conduct and to
conform his conduct to the law, id. , at 453. Petitioner's
family members offered additional evidence in support of his mental
retardation claim (e. g. , that petitioner is a "follower," id. , at 421). The Commonwealth contested the evidence of
retardation and presented testimony of a psychologist who found
"absolutely no evidence other than the IQ score . . . indicating
that [peti- [339] tioner] was in the least bit mentally retarded" and concluded
that petitioner was "of average intelligence, at least." Id. , at 476.

															The jury also heard testimony about petitioner's 16 prior felony
convictions for robbery, attempted robbery, abduction, use of a
firearm, and maiming. Id. , at 491-522. The victims of
these offenses provided graphic depictions of petitioner's violent
tendencies: He hit one over the head with a beer bottle, id. , at 406; he slapped a gun across another victim's
face, clubbed her in the head with it, knocked her to the ground,
and then helped her up, only to shoot her in the stomach, id. , at 411-413. The jury sentenced petitioner to death.
The Supreme Court of Virginia affirmed petitioner's sentence. 260
Va. 375, 534 S. E. 2d 312 (2000).

															II

															As the foregoing history demonstrates, petitioner's mental
retardation was a central issue at sentencing. The jury
concluded, however, that his alleged retardation was not a
compelling reason to exempt him from the death penalty in light of
the brutality of his crime and his long demonstrated propensity for
violence. "In upsetting this particularized judgment on the basis
of a constitutional absolute," the Court concludes that no one who
is even slightly mentally retarded can have sufficient "moral
responsibility to be subjected to capital punishment for any crime.
As a sociological and moral conclusion that is implausible; and it
is doubly implausible as an interpretation of the United States
Constitution." Thompson v. Oklahoma , 487 U. S. 815 , 863-864
(1988) (SCALIA, J., dissenting).

															Under our Eighth Amendment jurisprudence, a punishment is "cruel
and unusual" if it falls within one of two categories: "those modes
or acts of punishment that had been considered cruel and unusual at
the time that the Bill of Rights was adopted," Ford v.
Wainwright , 477
U. S. 399 , 405 (1986), and modes of punishment that are
inconsistent with [340] modern "'standards of decency,'" as evinced by objective
indicia, the most important of which is "legislation enacted by the
country's legislatures," Penry v. Lynaugh , 492 U. S. 302 , 330-331
(1989).

															The Court makes no pretense that execution of the mildly
mentally retarded would have been considered "cruel and unusual" in
1791. Only the severely or profoundly mentally
retarded, commonly known as "idiots," enjoyed any special status
under the law at that time. They, like lunatics, suffered a
"deficiency in will" rendering them unable to tell right from
wrong. 4 W. Blackstone, Commentaries on the Laws of England 24
(1769) (hereinafter Blackstone); see also Penry , 492 U.
S., at 331-332 ("[T]he term 'idiot' was generally used to describe
persons who had a total lack of reason or understanding, or an
inability to distinguish between good and evil"); id. , at
333 (citing sources indicating that idiots generally had an IQ of
25 or below, which would place them within the "profound" or
"severe" range of mental retardation under modern standards); 2 A.
Fitz-Herbert, Natura Brevium 233B (9th ed. 1794)
(originally published 1534) (An idiot is "such a person who cannot
account or number twenty pence, nor can tell who was his father or
mother, nor how old he is, etc., so as it may appear that he hath
no understanding of reason what shall be for his profit, or what
for his loss"). Due to their incompetence, idiots were "excuse[d]
from the guilt, and of course from the punishment, of any criminal
action committed under such deprivation of the senses." 4
Blackstone 25; see also Penry, supra , at 331. Instead,
they were often committed to civil confinement or made wards of the
State, thereby preventing them from "go[ing] loose, to the terror
of the king's subjects." 4 Blackstone 25; see also S. Brakel, J.
Parry, & B. Weiner, The Mentally Disabled and the Law 12-14 (3d
ed. 1985); 1 Blackstone 292-296; 1 M. Hale, Pleas of the Crown 33
(1st Am. ed. 1847). Mentally retarded offenders with less severe
impairments--those who were not "idiots"--suffered criminal
prosecution [341] and punishment, including capital punishment. See, e. g. , I. Ray, Medical Jurisprudence of Insanity 65, 87-92
(W. Overholser ed. 1962) (recounting the 1834 trial and execution
in Concord, New Hampshire, of an apparent "imbecile"--imbecility
being a less severe form of retardation which "differs from idiocy
in the circumstance that while in [the idiot] there is an utter
destitution of every thing like reason, [imbeciles] possess some
intellectual capacity, though infinitely less than is possessed by
the great mass of mankind"); A. Highmore, Law of Idiocy and Lunacy
200 (1807) ("The great difficulty in all these cases, is to
determine where a person shall be said to be so far deprived of his
sense and memory as not to have any of his actions imputed to him:
or where notwithstanding some defects of this kind he still appears
to have so much reason and understanding as will make him
accountable for his actions . . . ").

															The Court is left to argue, therefore, that execution of the
mildly retarded is inconsistent with the "evolving standards of
decency that mark the progress of a maturing society." Trop v.
Dulles , 356 U. S.
86 , 101 (1958) (plurality opinion) (Warren, C. J.). Before
today, our opinions consistently emphasized that Eighth Amendment
judgments regarding the existence of social "standards" "should be
informed by objective factors to the maximum possible extent" and
"should not be, or appear to be, merely the subjective views of
individual Justices." Coker v. Georgia , 433 U. S. 584 , 592 (1977)
(plurality opinion); see also Stanford v. Kentucky , 492 U. S. 361 ,
369 (1989); McCleskey v. Kemp , 481 U. S. 279 , 300
(1987); Enmund v. Florida , 458 U. S. 782 , 788
(1982). "First" among these objective factors are the "statutes
passed by society's elected representatives," Stanford,
supra , at 370; because it "will rarely if ever be the case
that the Members of this Court will have a better sense of the
evolution in views of the American people than do their elected
representatives," Thompson, supra , at 865 (SCALIA, J.,
dissenting). [342] The Court pays lipservice to these precedents as it miraculously
extracts a "national consensus" forbidding execution of the
mentally retarded, ante , at 316, from the fact that 18
States--less than half (47%) of the 38 States that permit
capital punishment (for whom the issue exists)--have very recently
enacted legislation barring execution of the mentally retarded.
Even that 47% figure is a distorted one. If one is to say, as the
Court does today, that all executions of the mentally
retarded are so morally repugnant as to violate our national
"standards of decency," surely the "consensus" it points to must be
one that has set its righteous face against all such
executions. Not 18 States, but only 7--18% of death penalty
jurisdictions--have legislation of that scope. Eleven of those that
the Court counts enacted statutes prohibiting execution of mentally
retarded defendants convicted after, or convicted of crimes
committed after, the effective date of the
legislation;[ Footnote 1 ] those already on death
row, or consigned there before the statute's effective date, or
even (in those States using the date of the crime as the criterion
of retroactivity) tried in the future for murders committed many
years ago, could be put to death. That is not a statement of
absolute moral repugnance, but one of current preference between
two tolerable approaches. Two of these States permit execution of
the mentally retarded in other situations as well: Kansas
apparently permits execution of all [343] except the severely mentally retarded;[ Footnote 2 ] New York permits execution of the mentally
retarded who commit murder in a correctional facility. N. Y. Crim.
Proc. Law 400.27. 12(d) (McKinney 2001); N. Y. Penal Law 125.27
(McKinney 2002).

															But let us accept, for the sake of argument, the Court's faulty
count. That bare number of States alone--18--should be enough to
convince any reasonable person that no "national consensus" exists.
How is it possible that agreement among 47% of the death penalty
jurisdictions amounts to "consensus"? Our prior cases have
generally required a much higher degree of agreement before finding
a punishment cruel and unusual on "evolving standards" grounds. In Coker, supra , at 595-596, we proscribed the death penalty
for rape of an adult woman after finding that only one
jurisdiction, Georgia, authorized such a punishment. In En mund, supra , at 789, we invalidated the death
penalty for mere participation in a robbery in which an accomplice
took a life, a punishment not permitted in 28 of the death penalty
States (78%). In Ford , 477 U. S., at 408, we supported the
common-law prohibition of execution of the insane with the
observation that "[t]his ancestral legacy has not outlived its
time," since not a single State authorizes such punishment. In Solem v. Helm , 463 U. S. 277 ,300 (1983),
we invalidated a life sentence without parole under a recidivist
statute by which the criminal "was treated more severely than he
would have been in any other State." What the Court calls evidence
of "consensus" in the present case (a fudged 47%) more closely
resembles evidence that we found inadequate [344] to establish consensus in earlier cases. Tison v.
Arizona , 481 U.
S. 137 , 154, 158 (1987), upheld a state law authorizing capital
punishment for major participation in a felony with reckless
indifference to life where only 11 of the 37 death penalty States
(30%) prohibited such punishment. Stanford , 492 U. S., at
372, upheld a state law permitting execution of defendants who
committed a capital crime at age 16 where only 15 of the 36 death
penalty States (42%) prohibited death for such offenders.

															Moreover, a major factor that the Court entirely disregards is
that the legislation of all 18 States it relies on is still in its
infancy. The oldest of the statutes is only 14 years old;[ Footnote 3 ] five were enacted last year;[ Footnote 4 ] over half were enacted within the past
eight years.[ Footnote 5 ] Few, if any, of the
States have had sufficient experience with these laws to know
whether they are sensible in the long term. It is "myopic to base
sweeping constitutional principles upon the narrow experience of [a
few] years." Coker , 433 U. S., at 614 (Burger, C. J.,
dissenting); see also Thompson , 487 U. S., at 854-855
(O'CONNOR, J., concurring in judgment).

															The Court attempts to bolster its embarrassingly feeble evidence
of "consensus" with the following: "It is not so much the number of
these States that is significant, but the consistency of
the direction of change." Ante , at 315 (emphasis added).
But in what other direction could we possibly see
change? Given that 14 years ago all the death penalty
statutes included the mentally retarded, any change
(except precipitate undoing of what had just been done) was bound [345] to be in the one direction the Court finds significant
enough to overcome the lack of real consensus. That is to say, to
be accurate the Court's "consistency-of-the-direction-of-change"
point should be recast into the following unimpressive observation:
"No State has yet undone its exemption of the mentally retarded,
one for as long as 14 whole years." In any event, reliance upon
"trends," even those of much longer duration than a mere 14 years,
is a perilous basis for constitutional adjudication, as JUSTICE
O'CONNOR eloquently explained in Thompson: "In 1846, Michigan became the first State to abolish the death
penalty . . . . In succeeding decades, other American States
continued the trend towards abolition . . . . Later, and
particularly after World War II, there ensued a steady and dramatic
decline in executions . . . . In the 1950's and 1960's, more States
abolished or radically restricted capital punishment, and
executions ceased completely for several years beginning in 1968 .
. . .

															"In 1972, when this Court heard arguments on the
constitutionality of the death penalty, such statistics might have
suggested that the practice had become a relic, implicitly rejected
by a new societal consensus . . . . We now know that any inference
of a societal consensus rejecting the death penalty would have been
mistaken. But had this Court then declared the existence of such a
consensus, and outlawed capital punishment, legislatures would very
likely not have been able to revive it. The mistaken premise of the
decision would have been frozen into constitutional law, making it
difficult to refute and even more difficult to reject." 487 U. S.,
at 854-855. Her words demonstrate, of course, not merely the peril of riding
a trend, but also the peril of discerning a consensus where there
is none. [346] The Court's thrashing about for evidence of "consensus" includes
reliance upon the margins by which state legislatures have
enacted bans on execution of the retarded. Ante , at 316.
Presumably, in applying our Eighth Amendment
"evolving-standards-of-decency" jurisprudence, we will henceforth
weigh not only how many States have agreed, but how many States
have agreed by how much. Of course if the percentage of
legislators voting for the bill is significant, surely the number
of people represented by the legislators voting for the
bill is also significant: the fact that 49% of the legislators in a
State with a population of 60 million voted against the
bill should be more impressive than the fact that 90% of the
legislators in a State with a population of 2 million voted for it. (By the way, the population of the death penalty
States that exclude the mentally retarded is only 44% of the
population of all death penalty States. U. S. Dept. of Commerce,
Bureau of Census, Statistical Abstract of the United States 21
(121st ed. 2001).) This is quite absurd. What we have looked for in
the past to "evolve" the Eighth Amendment is a consensus of the
same sort as the consensus that adopted the Eighth
Amendment: a consensus of the sovereign States that form the Union,
not a nose count of Americans for and against.

															Even less compelling (if possible) is the Court's argument, ante , at 316, that evidence of "national consensus" is to
be found in the infrequency with which retarded persons are
executed in States that do not bar their execution. To begin with,
what the Court takes as true is in fact quite doubtful. It is not
at all clear that execution of the mentally retarded is "uncommon," ibid. , as even the sources cited by the Court suggest, see ante , at 316, n. 20 (citing D. Keyes, W. Edwards, & R.
Perske, People with Mental Retardation are Dying Legally, 35 Mental
Retardation (Feb. 1997) (updated by Death Penalty Information
Center, available at http://www.advocacyone.org/deathpenalty.html
(as visited [347] June 12,2002) (showing that 12 States executed 35 allegedly
mentally retarded offenders during the period 1984-2000)). See also
Bonner & Rimer, Executing the Mentally Retarded Even as Laws
Begin to Shift, N. Y. Times, Aug. 7, 2000, p. Ai (reporting that
10% of death row inmates are retarded). If , however,
execution of the mentally retarded is "uncommon"; and if
it is not a sufficient explanation of this that the retarded
constitute a tiny fraction of society (1% to 3%), Brief for
American Psychological Association et al. as Amici Curiae 7; then surely the explanation is that mental retardation is a
constitutionally mandated mitigating factor at sentencing, Penry , 492 U. S., at 328. For that reason, even if there
were uniform national sentiment in favor of executing the
retarded in appropriate cases, one would still expect execution of
the mentally retarded to be "uncommon." To adapt to the present
case what the Court itself said in Stanford , 492 U. S., at
374: "[I]t is not only possible, but overwhelmingly probable, that
the very considerations which induce [today's majority] to believe
that death should never be imposed on [mentally retarded]
offenders . . . cause prosecutors and juries to believe that it
should rarely be imposed."

															But the Prize for the Court's Most Feeble Effort to fabricate
"national consensus" must go to its appeal (deservedly relegated to
a footnote) to the views of assorted professional and religious
organizations, members of the so-called "world community," and
respondents to opinion polls. Ante , at 316-317, n. 21. I
agree with THE CHIEF JUSTICE, ante , at 325-328 (dissenting
opinion), that the views of professional and religious
organizations and the results of opinion polls are
irrelevant.[ Footnote 6 ] Equally irrelevant are
the practices of the [348] "world community," whose notions of justice are (thankfully) not
always those of our people. "We must never forget that it is a
Constitution for the United States of America that we are
expounding . . . . [W]here there is not first a settled consensus
among our own people, the views of other nations, however
enlightened the Justices of this Court may think them to be, cannot
be imposed upon Americans through the Constitution." Thompson , 487 U. S., at 868-869, n. 4 (SCALIA, J.,
dissenting).

															III

															Beyond the empty talk of a "national consensus," the Court gives
us a brief glimpse of what really underlies today's decision:
pretension to a power confined neither by the moral
sentiments originally enshrined in the Eighth Amendment (its
original meaning) nor even by the current moral sentiments
of the American people. "'[T]he Constitution,'" the Court says,
"contemplates that in the end our own judgment will be
brought to bear on the question of the acceptability of the death
penalty under the Eighth Amendment.'" Ante , at 312
(quoting Coker , 433 U. S., at 597) (emphasis added). (The
unexpressed reason for this unexpressed "contemplation" of the
Constitution is presumably that really good lawyers have moral
sentiments superior to those of the common herd, whether in 1791 or
today.) The arrogance of this assumption of power takes one's
breath away. And it explains, of course, why the Court can be so
cavalier about the evidence of consensus. It is just a game, after
all. "'[I]n the end,'" Thompson, supra , at 823, n. 8
(plurality opinion (quoting Coker, supra , at 597
(plurality opinion))), it is the feelings and intuition of a majority of the Justices that count-"the
perceptions of decency, or of penology, or of mercy, entertained .
. . by a majority of the small and [349] unrepresentative segment of our society that sits on this
Court." Thompson, supra , at 873 (SCALIA, J.,
dissenting).

															The genuinely operative portion of the opinion, then, is the
Court's statement of the reasons why it agrees with the contrived
consensus it has found, that the "diminished capacities" of the
mentally retarded render the death penalty excessive. Ante , at 317-321. The Court's analysis rests on two
fundamental assumptions: (1) that the Eighth Amendment prohibits
excessive punishments, and (2) that sentencing juries or judges are
unable to account properly for the "diminished capacities" of the
retarded. The first assumption is wrong, as I explained at length
in Harmelin v. Michigan , 501 U. S. 957 , 966-990
(1991) (opinion of SCALIA, J.). The Eighth Amendment is addressed
to always-andeverywhere "cruel" punishments, such as the rack and
the thumbscrew. But where the punishment is in itself permissible,
"[t]he Eighth Amendment is not a ratchet, whereby a temporary
consensus on leniency for a particular crime fixes a permanent
constitutional maximum, disabling the States from giving effect to
altered beliefs and responding to changed social conditions." Id. , at 990. The second assumption--inability of judges or
juries to take proper account of mental retardation--is not only
unsubstantiated, but contradicts the immemorial belief, here and in
England, that they play an indispensable role in such
matters: "[I]t is very difficult to define the indivisible line that
divides perfect and partial insanity; but it must rest upon
circumstances duly to be weighed and considered both by the judge
and jury, lest on the one side there be a kind of inhumanity
towards the defects of human nature, or on the other side too great
an indulgence given to great crimes . . . . " 1 Hale, Pleas of the
Crown, at 30. Proceeding from these faulty assumptions, the Court gives two
reasons why the death penalty is an excessive punishment for all
mentally retarded offenders. First, the "dimin- [350] ished capacities" of the mentally retarded raise a "serious
question" whether their execution contributes to the "social
purposes" of the death penalty, viz., retribution and deterrence. Ante , at 318-319. (The Court conveniently ignores a third
"social purpose" of the death penalty--"incapacitation of dangerous
criminals and the consequent prevention of crimes that they may
otherwise commit in the future," Gregg v. Georgia , 428 U. S. 153 ,
183, n. 28 (1976) (joint opinion of Stewart, Powell, and STEVENS,
JJ.). But never mind; its discussion of even the other two does not
bear analysis.) Retribution is not advanced, the argument goes,
because the mentally retarded are no more culpable than
the average murderer, whom we have already held lacks sufficient
culpability to warrant the death penalty, see Godfrey v.
Georgia , 446 U.
S. 420 , 433 (1980) (plurality opinion). Ante , at 319.
Who says so? Is there an established correlation between mental
acuity and the ability to conform one's conduct to the law in such
a rudimentary matter as murder? Are the mentally retarded really
more disposed (and hence more likely) to commit willfully cruel and
serious crime than others? In my experience, the opposite is true:
being childlike generally suggests innocence rather than
brutality.

															Assuming, however, that there is a direct connection between
diminished intelligence and the inability to refrain from murder,
what scientific analysis can possibly show that a mildly retarded
individual who commits an exquisite torture-killing is "no more
culpable" than the "average" murderer in a holdup-gone-wrong or a
domestic dispute? Or a moderately retarded individual who commits a
series of 20 exquisite torture-killings? Surely culpability, and
deservedness of the most severe retribution, depends not merely (if
at all) upon the mental capacity of the criminal (above the level
where he is able to distinguish right from wrong) but also upon the
depravity of the crime--which is precisely why this sort of
question has traditionally been thought answerable not by a
categorical rule of the sort the Court today [351] imposes upon all trials, but rather by the sentencer's weighing
of the circumstances (both degree of retardation and depravity of
crime) in the particular case. The fact that juries continue to
sentence mentally retarded offenders to death for extreme crimes
shows that society's moral outrage sometimes demands execution of
retarded offenders. By what principle of law, science, or logic can
the Court pronounce that this is wrong? There is none. Once the
Court admits (as it does) that mental retardation does not render
the offender morally blameless, ante , at 318, there is no
basis for saying that the death penalty is never appropriate retribution, no matter how heinous the crime.
As long as a mentally retarded offender knows "the difference
between right and wrong," ibid. , only the sentencer can
assess whether his retardation reduces his culpability enough to
exempt him from the death penalty for the particular murder in
question.

															As for the other social purpose of the death penalty that the
Court discusses, deterrence: That is not advanced, the Court tells
us, because the mentally retarded are "less likely" than their
nonretarded counterparts to "process the information of the
possibility of execution as a penalty and . . . control their
conduct based upon that information." Ante , at 320. Of
course this leads to the same conclusion discussed earlier--that
the mentally retarded (because they are less deterred) are more
likely to kill--which neither I nor the society at large believes.
In any event, even the Court does not say that all mentally retarded individuals cannot "process the information of
the possibility of execution as a penalty and . . . control their
conduct based upon that information"; it merely asserts that they
are "less likely" to be able to do so. But surely the deterrent
effect of a penalty is adequately vindicated if it successfully
deters many, but not all, of the target class. Virginia's death
penalty, for example, does not fail of its deterrent effect simply
because some criminals are unaware that Virginia has the death penalty. In other words, the supposed fact
that some [352] retarded criminals cannot fully appreciate the death penalty has
nothing to do with the deterrence rationale, but is simply an echo
of the arguments denying a retribution rationale, discussed and
rejected above. I am not sure that a murderer is somehow less
blameworthy if (though he knew his act was wrong) he did not fully
appreciate that he could die for it; but if so, we should treat a
mentally retarded murderer the way we treat an offender who may be
"less likely" to respond to the death penalty because he was abused
as a child. We do not hold him immune from capital punishment, but
require his background to be considered by the sentencer as a
mitigating factor. Eddings v. Oklahoma , 455 U. S. 104 , 113-117
(1982).

															The Court throws one last factor into its grab bag of reasons
why execution of the retarded is "excessive" in all cases:

															Mentally retarded offenders "face a special risk of wrongful
execution" because they are less able "to make a persuasive showing
of mitigation," "to give meaningful assistance to their counsel,"
and to be effective witnesses. Ante , at 320-321. "Special
risk" is pretty flabby language (even flabbier than "less
likely")--and I suppose a similar "special risk" could be said to
exist for just plain stupid people, inarticulate people, even ugly
people. If this unsupported claim has any substance to it (which I
doubt), it might support a due process claim in all criminal
prosecutions of the mentally retarded; but it is hard to see how it
has anything to do with an Eighth Amendment claim that
execution of the mentally retarded is cruel and unusual. We have
never before held it to be cruel and unusual punishment to impose a
sentence in violation of some other constitutional
imperative.

															* * *

															Today's opinion adds one more to the long list of substantive
and procedural requirements impeding imposition of the death
penalty imposed under this Court's assumed power to invent a
death-is-different jurisprudence. None of those [353] requirements existed when the Eighth Amendment was adopted, and
some of them were not even supported by current moral consensus.
They include prohibition of the death penalty for "ordinary"
murder, Godfrey , 446 U. S., at 433, for rape of an adult
woman, Coker , 433 U. S., at 592, and for felony murder
absent a showing that the defendant possessed a sufficiently
culpable state of mind, Enmund, 458 U. S., at 801;
prohibition of the death penalty for any person under the age of 16
at the time of the crime, Thompson , 487 U. S., at 838
(plurality opinion); prohibition of the death penalty as the
mandatory punishment for any crime, Woodson v. North
Carolina , 428 U.
S. 280 , 305 (1976) (plurality opinion), Sumner v.
Shuman , 483 U. S.
66 , 77-78 (1987); a requirement that the sentencer not be given
unguided discretion, Furman v. Georgia , 408 U. S. 238 (1972) (per curiam) , a requirement that the sentencer be
empowered to take into account all mitigating circumstances, Lockett v. Ohio , 438 U. S. 586 , 604 (1978)
(plurality opinion), Eddings v. Oklahoma, supra , at 110;
and a requirement that the accused receive a judicial evaluation of
his claim of insanity before the sentence can be executed, Ford , 477 U. S., at 410-411 (plurality opinion). There is
something to be said for popular abolition of the death penalty;
there is nothing to be said for its incremental abolition by this
Court.

															This newest invention promises to be more effective than any of
the others in turning the process of capital trial into a game. One
need only read the definitions of mental retardation adopted by the
American Association on Mental Retardation and the American
Psychiatric Association (set forth in the Court's opinion, ante , at 308, n. 3) to realize that the symptoms of this
condition can readily be feigned. And whereas the capital defendant
who feigns insanity risks commitment to a mental institution until
he can be cured (and then tried and executed), Jones v. United
States , 463 U.
S. 354 , 370, and n. 20 (1983), the capital defendant who feigns
mental retardation risks nothing at all. The mere pendency [354] of the present case has brought us petitions by death row
inmates claiming for the first time, after multiple habeas
petitions, that they are retarded. See, e. g. , Moore v. Texas , 535 U. S. 1044 (2002) (SCALIA, J.,
dissenting from grant of applications for stay of execution).

															Perhaps these practical difficulties will not be experienced by
the minority of capital-punishment States that have very recently
changed mental retardation from a mitigating factor (to be accepted
or rejected by the sentencer) to an absolute immunity. Time will
tell--and the brief time those States have had the new disposition
in place (an average of 6.8 years) is surely not enough. But if the
practical difficulties do not appear, and if the other States share
the Court's perceived moral consensus that all mental
retardation renders the death penalty inappropriate for all crimes, then that majority will presumably follow
suit. But there is no justification for this Court's pushing them
into the experiment--and turning the experiment into a permanent
practice--on constitutional pretext. Nothing has changed the
accuracy of Matthew Hale's endorsement of the common law's
traditional method for taking account of guilt-reducing factors,
written over three centuries ago: "[Determination of a person's incapacity] is a matter of great
difficulty, partly from the easiness of counterfeiting this
disability . . . and partly from the variety of the degrees of this
infirmity, whereof some are sufficient, and some are insufficient
to excuse persons in capital offenses . . . .

															"Yet the law of England hath afforded the best method of trial,
that is possible, of this and all other matters of fact, namely, by
a jury of twelve men all concurring in the same judgment, by the
testimony of witnesses . . . , and by the inspection and direction
of the judge." 1 Pleas of the Crown, at 32-33. I respectfully dissent. Footnotes [ Footnote 1 ]

															Initially, both Jones and Atkins were indicted for capital
murder. The prosecution ultimately permitted Jones to plead guilty
to first-degree murder in exchange for his testimony against
Atkins. As a result of the plea, Jones became ineligible to receive
the death penalty.

															[ Footnote 2 ]

															Highly damaging to the credibility of Atkins' testimony was its
substantial inconsistency with the statement he gave to the police
upon his arrest. Jones, in contrast, had declined to make an
initial statement to the authorities.

															[ Footnote 3 ]

															The American Association on Mental Retardation (AAMR) defines
mental retardation as follows: "Mental retardation refers
to substantial limitations in present functioning. It is
characterized by significantly subaverage intellectual functioning,
existing concurrently with related limitations in two or more of
the following applicable adaptive skill areas: communication,
self-care, home living, social skills, community use,
selfdirection, health and safety, functional academics, leisure,
and work. Mental retardation manifests before age 18." Mental
Retardation: Definition, Classification, and Systems of Supports 5
(9th ed. 1992).

															The American Psychiatric Association's definition is similar:
"The essential feature of Mental Retardation is significantly
subaverage general intellectual functioning (Criterion A) that is
accompanied by significant limitations in adaptive functioning in
at least two of the following skill areas: communication,
self-care, home living, social/interpersonal skills, use of
community resources, self-direction, functional academic skills,
work, leisure, health, and safety (Criterion B). The onset must
occur before age 18 years (Criterion C). Mental
Retardation has many different etiologies and may be seen as a
final common pathway of various pathological processes that affect
the functioning of the central nervous system." Diagnostic and
Statistical Manual of Mental Disorders 41 (4th ed. 2000). "Mild"
mental retardation is typically used to describe people with an IQ
level of 50-55 to approximately 70. Id. , at 42-43.

															[ Footnote 4 ]

															The doctor interviewed Atkins, members of his family, and
deputies at the jail where he had been incarcerated for the
preceding 18 months. Dr. Nelson also reviewed the statements that
Atkins had given to the police and the investigative reports
concerning this case.

															[ Footnote 5 ]

															Dr. Nelson administered the Wechsler Adult Intelligence Scales
test (WAIS-III), the standard instrument in the United States for
assessing intellectual functioning. AAMR, Mental Retardation, supra. The WAIS-III is scored by adding together the
number of points earned on different subtests, and using a
mathematical formula to convert this raw score into a scaled score.
The test measures an intelligence range from 45 to 155. The mean
score of the test is 100, which means that a person receiving a
score of 100 is considered to have an average level of cognitive
functioning. A. Kaufman & E. Lichtenberger, Essentials of
WAIS-III Assessment 60 (1999). It is estimated that between 1 and 3
percent of the population has an IQ between 70 and 75 or lower,
which is typically considered the cutoff IQ score for the
intellectual function prong of the mental retardation definition. 2
Kaplan & Sadock's Comprehensive Textbook of Psychiatry 2952 (B.
Sadock & V. Sadock eds. 7th ed. 2000).

															At the sentencing phase, Dr. Nelson testified: "[Atkins'] full
scale IQ is 59. Compared to the population at large, that means
less than one percentile . . . . Mental retardation is a relatively
rare thing. It's about one percent of the population." App. 274.
According to Dr. Nelson, Atkins' IQ score "would automatically
qualify for Social Security disability income." Id. , at
280. Dr. Nelson also indicated that of the over 40 capital
defendants that he had evaluated, Atkins was only the second
individual who met the criteria for mental retardation. Id. , at 310. He testified that, in his opinion, Atkins'
limited intellect had been a consistent feature throughout his
life, and that his IQ score of 59 is not an "aberration, malingered
result, or invalid test score." Id. , at 308.

															[ Footnote 6 ]

															Dr. Samenow's testimony was based upon two interviews with
Atkins, a review of his school records, and interviews with
correctional staff. He did not administer an intelligence test, but
did ask Atkins questions taken from the 1972 version of the
Wechsler Memory Scale. Id. , at 524-525, 529. Dr. Samenow
attributed Atkins' "academic performance [that was] by and large
terrible" to the fact that he "is a person who chose to pay
attention sometimes, not to pay attention others, and did poorly
because he did not want to do what he was required to do." Id. , at 480-481.

															[ Footnote 7 ]

															Thus, we have read the text of the Amendment to prohibit all
excessive punishments, as well as cruel and unusual punishments
that mayor may not be excessive.

															[ Footnote 8 ]

															Jerome Bowden, who was identified as having mental retardation
when he was 14 years old, was scheduled for imminent execution in
Georgia in June 1986. The Georgia Board of Pardons and Paroles
granted a stay following public protests over his execution. A
psychologist selected by the State evaluated Bowden and determined
that he had an IQ of 65, which is consistent with mental
retardation. Nevertheless, the board lifted the stay and Bowden was
executed the following day. The board concluded that Bowden
understood the nature of his crime and his punishment and therefore
that execution, despite his mental deficiencies, was permissible.
See Montgomery, Bowden's Execution Stirs Protest, Atlanta Journal,
Oct. 13, 1986, p. AI.

															[ Footnote 9 ]

															Ga. Code Ann. 17-7-131(j) (Supp. 1988).

															[ Footnote 10 ]

															The Anti-Drug Abuse Act of 1988, Pub. L. 100-690, 7001(l) , 102 Stat. 4390,21 U. S. C. 848(l). Congress expanded the federal death penalty law in 1994. It again
included a provision that prohibited any individual with mental
retardation from being sentenced to death or executed. Federal
Death Penalty Act of 1994, 18 U. S. C. 3596(c).

															[ Footnote 11 ]

															Md. Ann. Code, Art. 27, 412(f)(I) (1989).

															[ Footnote 12 ]

															Ky. Rev. Stat. Ann. 532.130, 532.135, 532.140; Tenn. Code Ann.
3913-203; N. M. Stat. Ann. 31-20A-2.1; Ark. Code Ann. 5-4-618;
Colo. Rev. Stat. 16-9-401; Wash. Rev. Code 10.95.030; Ind. Code
35-36-9-2 through 35-36-9-6; Kan. Stat. Ann. 21-4623.

															[ Footnote 13 ]

															N. Y. Crim. Proc. Law 400.27. However, New York law provides
that a sentence of death "may not be set aside . . . upon the
ground that the defendant is mentally retarded" if "the killing
occurred while the defendant was confined or under custody in a
state correctional facility or local correctional institution." N.
Y. Crim. Proc. Law 400.27.12(d) (McKinney 2001-2002 Interim Pocket
Part).

															[ Footnote 14 ]

															Neb. Rev. Stat. 28-105.01.

															[ Footnote 15 ]

															S. D. Codified Laws 23A-27A-26.1; Ariz. Rev. Stat. Ann.
13-703.02; Conn. Gen. Stat. 53a-46a; Fla. Stat. 921.137; Mo. Rev.
Stat. 565.030; 2001-346 N. C. Sess. Laws p. 45.

															[ Footnote 16 ]

															House Bill No. 236 passed the Texas House on April 24, 2001, and
the Senate version, S. 686, passed the Texas Senate on May 16,
2001. Governor Perry vetoed the legislation on June 17, 2001. In
his veto statement, the Texas Governor did not express
dissatisfaction with the principle of categorically excluding the
mentally retarded from the death penalty. In fact, he stated: "We
do not execute mentally retarded murderers today." See Veto
Proclamation for H. B. No. 236. Instead, his motivation to veto the
bill was based upon what he perceived as a procedural flaw: "My
opposition to this legislation focuses on a serious legal flaw in
the bill. House Bill No. 236 would create a system whereby the jury
and judge are asked to make the same determination based on two
different sets of facts . . . . Also of grave concern is the fact
that the provision that sets up this legally flawed process never
received a public hearing during the legislative process." Ibid. [ Footnote 17 ]

															Virginia Senate Bill No. 497 (2002); House Bill No. 957 (2002);
see also Nevada Assembly Bill 353 (2001). Furthermore, a commission
on capital punishment in Illinois has recently recommended that
Illinois adopt a statute prohibiting the execution of mentally
retarded offenders. Report of the Governor's Commission on Capital
Punishment 156 (Apr. 2002).

															[ Footnote 18 ]

															A comparison to Stanford v. Kentucky , 492 U. S. 361 (1989), in
which we held that there was no national consensus prohibiting the
execution of juvenile offenders over age 15, is telling. Although
we decided Stanford on the same day as Penry ,
apparently only two state legislatures have raised the threshold
age for imposition of the death penalty. Mont. Code Ann. 45-5-102
(1999); Ind. Code 35-50-2-3 (1998).

															[ Footnote 19 ]

															App. D to Brief for AAMR et al. as Amici Curiae. [ Footnote 20 ]

															Those States are Alabama, Texas, Louisiana, South Carolina, and
Virginia. D. Keyes, W. Edwards, & R. Perske, People with Mental
Retardation are Dying Legally, 35 Mental Retardation (Feb. 1997)
(updated by Death Penalty Information Center, available at http://www.advocacyone.org/deathpenalty.html (as visited June 18, 2002)).

															[ Footnote 21 ]

															Additional evidence makes it clear that this legislative
judgment reflects a much broader social and professional consensus.
For example, several organizations with germane expertise have
adopted official positions opposing the imposition of the death
penalty upon a mentally retarded offender. See Brief for American
Psychological Association et al. as Amici Curiae; Brief
for AAMR et al. as Amici Curiae. In addition,
representatives of widely diverse religious communities in the
United States, reflecting Christian, Jewish, Muslim, and Buddhist
traditions, have filed an amicus curiae brief explaining
that even though their views about the death penalty differ, they
all "share a conviction that the execution of persons with mental
retardation cannot be morally justified." Brief for United States
Catholic Conference et al. as Amici Curiae 2. Moreover,
within the world community, the imposition of the death penalty for
crimes committed by mentally retarded offenders is overwhelmingly
disapproved. Brief for European Union as Amicus Curiae 4.
Finally, polling data shows a widespread consensus among Americans,
even those who support the death penalty, that executing the
mentally retarded is wrong. Bonner & Rimer, Executing the
Mentally Retarded Even as Laws Begin to Shift, N. Y. Times, Aug.
7,2000, p. AI; App. B to Brief for AAMR et al. as Amici
Curiae (appending approximately 20 state and national polls on
the issue). Although these factors are by no means dispositive,
their consistency with the legislative evidence lends further
support to our conclusion that there is a consensus among those who
have addressed the issue. See Thompson v. Oklahoma , 487 U. S. 815 ,
830, 831, n. 31 (1988) (considering the views of "respected
professional organizations, by other nations that share our
Anglo-American heritage, and by the leading members of the Western
European community").

															[ Footnote 22 ]

															The statutory definitions of mental retardation are not
identical, but generally conform to the clinical definitions set
forth in n. 3, supra. [ Footnote 23 ]

															J. McGee & F. Menolascino, The Evaluation of Defendants with
Mental Retardation in the Criminal Justice System, in The Criminal
Justice System and Mental Retardation 55, 58-60 (R. Conley, R.
Luckasson, & G. Bouthilet eds. 1992); Appelbaum &
Appelbaum, Criminal-Justice Related Competencies in Defendants with
Mental Retardation, 14 J. of Psychiatry & L. 483, 487-489
(Winter 1994).

															[ Footnote 24 ]

															See, e. g. , Ellis & Luckasson, Mentally
Retarded Criminal Defendants, 53 Geo. Wash. L. Rev. 414, 429
(1985); Levy-Shiff, Kedem, & Sevillia, Ego Identity in Mentally
Retarded Adolescents, 94 Am. J. Mental Retardation 541, 547 (1990);
Whitman, Self Regulation and Mental Retardation, 94 Am. J. Mental
Retardation 347, 360 (1990); Everington & Fulero, Competence to
Confess: Measuring Understanding and Suggestibility of Defendants
with Mental Retardation, 37 Mental Retardation 212, 212-213, 535
(1999) (hereinafter Everington & Fulero).

															[ Footnote 25 ]

															See Everington & Fulero 212-213. Despite the heavy burden
that the prosecution must shoulder in capital cases, we cannot
ignore the fact that in recent years a disturbing number of inmates
on death row have been exonerated. These exonerations have included
at least one mentally retarded person who unwittingly confessed to
a crime that he did not commit. See Baker, Death-Row Inmate Gets
Clemency; Agreement Ends Day of Suspense, Washington Post, Jan. 15,
1994, p. A1.

															[ Footnote * ]

															Apparently no such statistics exist. See Brief for American
Association on Mental Retardation et al. as Amici Curiae 19, n. 29 (noting that "actions by individual prosecutors and by
juries are difficult to quantify with precision"). Petitioner's
inability to muster studies in his favor ought to cut against him,
for it is his "heavy burden," Stanford v. Kentucky , 492 U. S. 361 ,
373 (1989) (internal quotation marks omitted), to establish a
national consensus against a punishment deemed acceptable by the
Virginia Legislature and jury who sentenced him. Furthermore, it is
worth noting that experts have estimated that as many as 10 percent
of death row inmates are mentally retarded, see R. Bonner & S.
Rimer, Executing the Mentally Retarded Even as Laws Begin to Shift,
N. Y. Times, Aug. 7, 2000, p. AI, a number which suggests that
sentencing juries are not as reluctant to impose the death penalty
on defendants like petitioner as was the case in Coker v.
Georgia , 433 U.
S. 584 (1977), and Enmund v. Florida , 458 U. S. 782 (1982).

															[ Footnote 1 ]

															See Ariz. Rev. Stat. Ann. 13-703.02(1) (Supp. 2001); Ark. Code
Ann. 5-4-618(d)(1) (1997); Reams v. State , 322 Ark. 336,
340, 909 S. W. 2d 324, 326-327 (1995); Fla. Stat. 921.137(8) (Supp.
2002); Ga. Code Ann. 17-7-131(j) (1997); Ind. Code 35-36-9-6
(1998); Rondon v. State , 711 N. E. 2d 506, 512 (Ind.
1999); Kan. Stat. Ann. 21-4623(d), 21-4631(c) (1995); Ky. Rev.
Stat. Ann. 532.140(3) (1999); Md. Ann. Code, Art. 27, 412(g)
(1996); Booth v. State , 327 Md. 142, 166-167, 608 A. 2d
162, 174 (1992); Mo. Rev. Stat. 565.030(7) (Supp. 2001); N. Y.
Crim. Proc. Law 400.27.12(c) (McKinney Supp. 2002); 1995 N. Y.
Laws, ch. 1, 38; Tenn. Code Ann. 39-13-203(b) (1997); Van Tran
v. State , 66 S. W. 3d 790, 798799 (Tenn. 2001).

															[ Footnote 2 ]

															The Kansas statute defines "mentally retarded" as "having
significantly subaverage general intellectual functioning . . . to
an extent which substantially impairs one's capacity to appreciate
the criminality of one's conduct or to conform one's conduct to the
requirements of law." Kan. Stat. Ann. 21-4623(e) (2001). This
definition of retardation, petitioner concedes, is analogous to the
Model Penal Code's definition of a "mental disease or defect"
excusing responsibility for criminal conduct, see ALl, Model Penal
Code 4.01 (1985), which would not include mild mental retardation.
Reply Brief for Petitioner 3, n. 4.

															[ Footnote 3 ]

															Ga. Code Ann. 17-7-131(j).

															[ Footnote 4 ]

															Ariz. Rev. Stat. Ann. 13-703.02; Conn. Gen. Stat. 53a-46a(h);
Fla. Stat. 921.137; Mo. Rev. Stat. 565.030(4)-(7); N. C. Gen. Stat.
15A-2005.

															[ Footnote 5 ]

															In addition to the statutes cited n. 4, supra , see S.
D. Codified Laws 23A-27A-26.1 (enacted 2000); Neb. Rev. Stat.
28-105.01(2)-(5) (1998); N. Y. Crim. Proc. Law 400.27(12) (1995);
Ind. Code 35-36-9-6 (1994); Kan. Stat. Ann. 21-4623 (1994).

															[ Footnote 6 ]

															And in some cases positively counterindicative. The Court cites,
for example, the views of the United States Catholic Conference,
whose members are the active Catholic Bishops of the United States.
See ante , at 316, n. 21 (citing Brief for United States
Catholic Conference et al. as Amici Curiae 2). The
attitudes of that body regarding crime and punishment are so far
from being representative, even of the views of Catholics, that
they are currently the object of intense national (and entirely
ecumenical) criticism.

Summary: The Supreme Court case Atkins v. Virginia (2002) ruled that executing individuals with intellectual disabilities violates the Eighth Amendment's ban on cruel and unusual punishment. This decision was based on evolving standards of decency and the recognition that individuals with intellectual disabilities have reduced personal culpability. The Court noted that individuals with intellectual disabilities often have impairments in reasoning, judgment, and control of their impulses, which can lead to unreliable and unfair capital proceedings. The Court's decision reflected a national consensus, with many states already prohibiting the execution of intellectually disabled individuals.