Rhetoric - 2001 The Case

The Case

BEFORE ESPOSITO, HULL, and RICHARD, JJ.

Circuit Judge Phillip Esposito delivered the opinion of the Court: In this case, we must decide whether petitioner, L. Stanley Cuppe, was sentenced to death in violation of the Eighth Amendment because the Eighth Amendment categorically prohibits Cuppe's execution because he is mentally retarded.

I. BACKGROUND AND FACTS

On the morning of October 25, 1994, Pamela Blades was brutally raped, beaten, and stabbed with a pair of scissors in her home in Black Hawk, Ionia. She died a few hours later in the course of emergency treatment. Before she died, she described her assailant. Her description led two local sheriff's deputies to suspect Cuppe, who had recently been released on parole after conviction on another rape charge. Cuppe subsequently gave two statements confessing to the crime and was charged with capital murder.

At a competency hearing held before trial, a clinical psychologist, Dr. Robert Orr, testified that Cuppe was mentally retarded. As a child, Cuppe was diagnosed as having organic brain damage, which was probably caused by trauma to the brain at birth. Cuppe was tested over the years as having an IQ between 50 and 63, which indicates mild to moderate retardation. Dr. Orr's own testing before the trial indicated that Cuppe had an IQ of 54. Dr. Orr's evaluation also revealed that Cuppe, who was 22 years old at the time of the crime, had the mental age of a 6 1/2-year-old, which means that "he has the ability to learn and the learning or the knowledge of the average 6 1/2 year old kid." Cuppe's social maturity, or ability to function in the world, was that of a 9- or 10-year-old. Dr. Orr testified that "there's a point at which anyone with [Cuppe's] IQ is always incompetent, but, you know, this man is more in the borderline range."

The procedure in this case is significant. The jury found Cuppe competent to stand trial. Throughout the United States, death penalty cases are in two phases: the first is to determine guilt or innocence. The second phase, if there is a conviction, is known as the penalty phase, where the jury makes the initial determination (subject to the trial judge's final decision) of the propriety of the death penalty. Mandatory appeals follow.

The guilt-innocence phase of the trial began on March 24, 1995. The trial court determined that Cuppe's confessions were voluntary, and they were introduced into evidence. At trial, Cuppe raised an insanity defense and presented the testimony of a psychiatrist, Dr. Kenneth Dryden. Dr. Dryden testified that Cuppe suffered from organic brain damage and moderate retardation, which resulted in poor impulse control and an inability to learn from experience.

Dr. Dryden indicated that Cuppe's brain damage was probably caused at birth, but may have been caused by beatings and multiple injuries to the brain at an early age. In Dr. Dryden's judgment, Cuppe was suffering from an organic brain disorder at the time of the offense which made it impossible for him to appreciate the wrongfulness of his conduct or to conform his conduct to the law.

Cuppe's mother testified at trial that Cuppe was unable to learn in school and never finished the first grade. Cuppe's sister testified that their mother had frequently beaten him over the head with a belt when he was a child. Cuppe was also routinely locked in his room without access to a toilet for long periods of time. As a youngster, Cuppe was in and out of a number of state schools and hospitals, until his father removed him from state schools altogether when he was 12. Cuppe's aunt subsequently struggled for over a year to teach Cuppe how to print his name.

The State introduced the testimony of two psychiatrists to rebut the testimony of Dr. Dryden. Dr. Vladimir Tretiak testified that although Cuppe was a person of limited mental ability, he was not suffering from any mental illness or defect at the time of the crime, and that he knew the difference between right and wrong and had the potential to honor the law. In his view, Cuppe had characteristics consistent with an antisocial personality, including an inability to learn from experience and a tendency to be impulsive and to violate society's norms. He testified further that Cuppe's low IQ scores under-estimated his alertness and understanding of what went on around him.

Dr. Gordon Howe also testified for the State that Cuppe was legally sane at the time of the offense and had a "full-blown anti-social personality." In addition, Dr. Howe testified that he personally diagnosed Cuppe as being mentally retarded in 1983 and again in 1987, and that Cuppe "had a very bad life generally, bringing up." In Dr. Howe's view, Cuppe "had been socially and emotionally deprived and he had not learned to read and write adequately." Although they disagreed with the defense psychiatrist over the extent and cause of Cuppe's mental limitations, both psychiatrists for the State acknowledged that Cuppe was a person of extremely limited mental ability, and that he seemed unable to learn from his mistakes.

The jury rejected Cuppe's insanity defense and found him guilty of capital murder. The following day, at the close of the penalty hearing, the jury recommended the imposition of the death penalty upon Cuppe. The trial judge agreed.

Following exhaustion of his appellate rights and post-conviction relief rights in the courts of Ionia, Cuppe then filed this federal habeas corpus petition challenging his death sentence. The district court denied relief without opinion. The appeal to this Court followed. (n.1)

N.1. No issues are presented or argued by the parties in connection with the procedures used in the Ionia state courts or in the federal courts. Instead, the issues are confined to the merits of the issues presented in section II.

II. THE ISSUES BEFORE THIS COURT

Cuppe's claim is that it would be cruel and unusual punishment, prohibited by the Eighth Amendment, to execute a mentally retarded person like himself with the reasoning capacity of a 7-year-old. He argues that because of their mental disabilities, mentally retarded people do not possess the level of moral culpability to justify imposing the death sentence. He also argues that there is an emerging national consensus against executing the mentally retarded.

The State responds that there is insufficient evidence of a national consensus against executing the retarded, and that existing procedural safeguards adequately protect the interests of mentally retarded persons such as Cuppe.

We must, therefore, resolve two questions within the larger, single issue: is it cruel and unusual punishment under the Eighth Amendment to execute a mentally retarded person with Cuppe's reasoning ability? Under settled Eighth Amendment legal principles, and the parties' arguments, the two lines of inquiry we must pursue are:

1. Is there a historical basis or a national consensus that execution of a mentally retarded person is "cruel and unusual" punishment?

2. Does the execution of mentally retarded criminal offenders Ð as a class Ð make no measurable contribution to the acceptable goals of punishment? Each is discussed in turn.

III. IS THERE A HISTORICAL BASIS OR A NATIONAL CONSENSUS THAT EXECUTION OF A MENTALLY RETARDED PERSON IS "CRUEL AND UNUSUAL" PUNISHMENT?

The Eighth Amendment categorically prohibits the infliction of cruel and unusual punishments. At a minimum, the Eighth Amendment prohibits punishment considered cruel and unusual at the time the Bill of Rights was adopted. Ford v. Wainwright, 477 U.S. 399 (1986); Solem v. Helm, 463 U.S. 277, 285, 286 (1983). We therefore begin with the historical analysis.

A. The Historical Analysis

It was well settled at common law that "idiots," together with "lunatics," were not subject to punishment for criminal acts committed under those incapacities. As Blackstone wrote: "The second case of a deficiency in will, which excuses from the guilt of crimes, arises also from a defective or vitiated understanding, viz. in an idiot or a lunatic. . . . [I]diots and lunatics are not chargeable for their own acts, if committed when under these incapacities: no, not even for treason itself. . . . [A] total idiocy, or absolute insanity, excuses from the guilt, and of course from the punishment, of any criminal action committed under such deprivation of the senses. . . ." 4 W. Blackstone, Commentaries *24 - *25 (emphasis in original).

See also 1 W. Hawkins, Pleas of the Crown 1-2 (7th ed. 1795) ("[T]hose who are under a natural disability of distinguishing between good and evil, as . . . ideots, and lunaticks [sic] are not punishable by any criminal prosecution whatsoever"). Idiocy was understood as "a defect of understanding from the moment of birth," in contrast to lunacy, which was "a partial derangement of the intellectual faculties, the senses returning at uncertain intervals." Id., at 2, n. 2.

There was no one definition of idiocy at common law, but the 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. Hale wrote that a person who is deaf and mute from birth "is in presumption of law an ideot [sic] . . . because he hath no possibility to understand what is forbidden by law to be done, or under what penalties: but if it can appear, that he hath the use of understanding, . . . then he may be tried, and suffer judgment and execution." 1 M. Hale, Pleas of the Crown 34 (1736) (footnote omitted); see also id., at 29 (citing A. Fitzherbert, 2 Natura Brevium 233 (7th ed. 1730)); Trial of Edward Arnold, 16 How. St. Tr. 695, 765 (Eng. 1724) ("[A] man that is totally deprived of his understanding and memory, and doth not know what he is doing, no more than an infant, than a brute, or a wild beast, such a one is never the object of punishment"); S. Glueck, Mental Disorder and the Criminal Law 128-144 (1925).

The common law prohibition against punishing "idiots" and "lunatics" for criminal acts was the precursor of the insanity defense, which today generally includes "mental defect" as well as "mental disease" as part of the legal definition of insanity. See, e. g., American Law Institute, Model Penal Code 4.01, p. 61 (1985) ("A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity either to appreciate the criminality [wrongfulness] of his conduct or to conform his conduct to the requirements of law"); 18 U.S.C. 17 (1982 ed., Supp. V) (it is an affirmative defense to federal prosecution if "the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or the wrongfulness of his acts" at the time the offense was committed). See generally Ellis & Luckasson, Mentally Retarded Criminal Defendants, 53 Geo. Wash. L. Rev. 414, 432-444 (1985).

In its emphasis on a permanent, congenital mental deficiency, the old common law notion of "idiocy" bears some similarity to the modern definition of mental retardation. Ellis & Luckasson, supra, at 417. The common law prohibition against punishing "idiots" generally applied, however, to persons of such severe disability that they lacked the reasoning capacity to form criminal intent or to understand the difference between good and evil. In the 19th and early 20th centuries, the term "idiot" was used to describe the most retarded of persons, corresponding to what is called "profound" and "severe" retardation today. See American Association on Mental Retardation ("AAMR"), Classification in Mental Retardation 179 (H. Grossman ed. 1983); id., at 9 ("idiots" generally had IQ of 25 or below).

The common law prohibition against punishing "idiots" for their crimes suggests that it may indeed be "cruel and unusual" punishment to execute persons who are profoundly or severely retarded and wholly lacking the capacity to appreciate the wrongfulness of their actions. Because of the protections afforded by the insanity defense today, such a person is not likely to be convicted or face the prospect of punishment. See ABA Standards for Criminal Justice 7-9.1, commentary, p. 460 (2d ed. 1980) (most retarded people who reach the point of sentencing are mildly retarded). Moreover, under Ford v. Wainwright, 477 U.S. 399 (1986), someone who is "unaware of the punishment they are about to suffer and why they are to suffer it" cannot be executed. Id., at 422 (Powell, J., concurring in part and concurring in judgment).

Such a case is not before us today. Cuppe was found competent to stand trial. In other words, he was found to have the ability to consult with his lawyer with a reasonable degree of rational understanding, and was found to have a rational as well as factual understanding of the proceedings against him. Dusky v. United States, 362 U.S. 402 (1960). In addition, the jury rejected his insanity defense, which reflected their conclusion that Cuppe knew that his conduct was wrong and was capable of conforming his conduct to the requirements of the law. Ionia Penal Code Ann.

B. The National Consensus

The prohibitions of the Eighth Amendment are not limited, however, to those practices condemned by the common law in 1789. Ford, supra, at 406; Gregg v. Georgia, 428 U.S. 153, 176 (1976). The prohibition against cruel and unusual punishments also recognizes the "evolving standards of decency that mark the progress of a maturing society." Trop v. Dulles, 356 U.S. 86, 101 (1958) (plurality opinion); Ford, supra, at 406.

In discerning those "evolving standards," the Supreme Court has looked to objective evidence of how our society views a particular punishment today. See Coker v. Georgia, 433 U.S. 584, 593-597 (1977); Enmund v. Florida, 458 U.S. 782, 788, 796 (1982). The clearest and most reliable objective evidence of contemporary values is the legislation enacted by the country's legislatures. The Supreme Court has also looked to data concerning the actions of sentencing juries. Enmund, supra, at 794-796; Thompson v. Oklahoma, 487 U.S. 815, 831 (1988) (plurality opinion).

Cuppe argues, however, that there is objective evidence today of an emerging national consensus against execution of the mentally retarded, reflecting the "evolving standards of decency that mark the progress of a maturing society." Trop v. Dulles, 356 U.S. at 101. In our view, this issue was decided against Cuppe with the United States Supreme Court's decision in Penry v. Lynaugh, 492 U.S. 302 (1989).

At that time, the Supreme Court reviewed the law as it existed. The then-recently enacted federal Anti-Drug Abuse Act of 1988, Pub. L. 100-690, 7001(1), 102 Stat. 4390, 21 U.S.C. 848(l) (1988 ed.), prohibits execution of a person who is mentally retarded. At that time, only one State, however, banned execution of retarded persons who have been found guilty of a capital offense. Ga. Code Ann. 17-7-131(j) (Supp. 1988). Maryland became the second in July, 1989. Md. Ann. Code, Art. 27, 412(f)(1) (1989).

Now, in contrast to the time when Penry was decided, that number is now up to 13. The 13 are Arkansas, Colorado, Georgia, Indiana, Kansas, Kentucky, Maryland, Nebraska, New Mexico, South Dakota, Tennessee, Washington and New York, except for murder by a prisoner.

However, we believe this is still insufficient evidence of a true national consensus. As the Supreme Court decided in Penry, the contrast to Ford v. Wainwright is instructive. Ford held that the Eighth Amendment prohibits execution of the insane, but there was considerably more evidence of a national consensus available. No State permitted the execution of the insane, and 26 States had statutes explicitly requiring suspension of the execution of a capital defendant who became insane. Ford, 477 U.S. at 408, n. 2. Other States had adopted the common law prohibition against executing the insane. Ibid.

Moreover, in examining the objective evidence of contemporary standards of decency in Thompson v. Oklahoma, the plurality in Penry noted that 18 States expressly established a minimum age in their death penalty statutes, and all of them required that the defendant have attained at least the age of 16 at the time of the offense. 487 U.S. at 829, n. 30.

Simply put, the numbers are not present. Eleven more states are present than in 1989, but this is not enough to compel the conclusion that we must hold Ð contrary to Penry Ð that the constitutional contours of the Eighth Amendment have changed. There are only 13 of 51 states that ban the practice. (n.2) We are still short of the 26 in Ford, and even then, Ford was counting "backwards" from the premise that NO state permitted such executions.

(N.3) The dissent's view of the national consensus analysis is colored Ðfatally so in our view Ð by its review of the legislative actions in Ionia. Ionia cannot be counted, and even if it became the 14th state, it would still not create a majority. The perils of counting states on the basis of proposed, rather than enacted, legislation is evident. For example, in 2001:

• Florida has sought to reform its law to curb appeals and speed up executions
• Indiana has considered a bill intended to make sure relatives of crime victims have the right to tell a judge how the death of a loved one affected them
• Tennessee, Maryland, Nevada and New Mexico have all considered, but rejected, a total moratorium on death penalties.
• North Carolina and Oregon want to expand the list of crimes subject to the death penalty

Yet certainly the dissenting opinion would not remove Maryland from its claim to majority status on the basis of this legislation.

Cuppe does not offer any evidence of the general behavior of juries with respect to sentencing mentally retarded defendants, nor of decisions of prosecutors. He points instead to several public opinion surveys that indicate strong public opposition to execution of the retarded. For example, a poll taken in Texas found that 86% of those polled supported the death penalty, but 73% opposed its application to the mentally retarded. Austin American Statesman, November 15, 1988, p. B3. A Florida poll found 71% of those surveyed were opposed to the execution of mentally retarded capital defendants, while only 12% were in favor. A Georgia poll found 66% of those polled opposed to the death penalty for the retarded, 17% in favor, with 16% responding that it depends how retarded the person is. In addition, the AAMR, the country's oldest and largest organization of professionals working with the mentally retarded, opposes the execution of persons who are mentally retarded. AAMR, Resolution on Mental Retardation and the Death Penalty, January 1988. The public sentiment expressed in these and other polls and resolutions may ultimately find expression in legislation, which is an objective indicator of contemporary values upon which we can rely. But at present, there is insufficient evidence of a national consensus against executing mentally retarded people convicted of capital offenses for us to conclude that it is categorically prohibited by the Eighth Amendment.

IV. DOES THE EXECUTION OF MENTALLY RETARDED CRIMINAL OFFENDERS Ð AS A CLASS Ð MAKE NO MEASURABLE CONTRIBUTION TO THE ACCEPTABLE GOALS OF PUNISHMENT?

Underlying our basic Eighth Amendment case holdings is the concept that punishment should be directly related to the personal culpability of the criminal defendant. If the sentencer is to make an individualized assessment of the appropriateness of the death penalty, "evidence about the defendant's background and character is relevant because of the belief, long held by this society, that defendants who commit criminal acts that are attributable to a disadvantaged background, or to emotional and mental problems, may be less culpable than defendants who have no such excuse." California v. Brown, 479 U.S. 538, 545 (1987) (O'Connor, J., concurring).

Moreover, Eddings v. Oklahoma, 455 U.S. 104 (1982), makes clear that it is not enough simply to allow the defendant to present mitigating evidence to the sentencer. The sentencer must also be able to consider and give effect to that evidence in imposing sentence. Hitchcock v. Dugger, 481 U.S. 393 (1987). Only then can we be sure that the sentencer has treated the defendant as a "uniquely individual human bein[g]" and has made a reliable determination that death is the appropriate sentence. Woodson v. North Carolina, 428 U.S. 280, 304-305 (1976). "Thus, the sentence imposed at the penalty stage should reflect a reasoned moral response to the defendant's background, character, and crime." California v. Brown, supra, at 545.

Relying largely on objective evidence such as the judgments of legislatures and juries, the judiciary has also considered whether application of the death penalty to particular categories of crimes or classes of offenders violates the Eighth Amendment because it "makes no measurable contribution to acceptable goals of punishment and hence is nothing more than the purposeless and needless imposition of pain and suffering" or because it is "grossly out of proportion to the severity of the crime." Coker v. Georgia, 433 U.S. at 592 (plurality opinion); Thompson v. Oklahoma, 487 U.S. at 833 (plurality opinion); Tison v. Arizona, 481 U.S. 137 (1987); Enmund v. Florida, 458 U.S. at 798-801. Gregg noted that "[t]he death penalty is said to serve two principal social purposes: retribution and deterrence of capital crimes by prospective offenders." Gregg v. Georgia, 428 U.S. at 183 (joint opinion of Stewart, Powell, and Stevens, JJ.). "The heart of the retribution rationale is that a criminal sentence must be directly related to the personal culpability of the criminal offender." Tison v. Arizona, supra, at 149. See also Enmund, supra, at 825 (O'Connor, J., dissenting) (the Eighth Amendment concept of "proportionality requires a nexus between the punishment imposed and the defendant's blameworthiness").

Cuppe argues that execution of a mentally retarded person like himself with a reasoning capacity of approximately a 7-year-old would be cruel and unusual because it is disproportionate to his degree of personal culpability. Brief for Petitioner 49-50. Just as the plurality in Thompson reasoned that a juvenile is less culpable than an adult for the same crime, Cuppe argues that mentally retarded people do not have the judgment, perspective, and self-control of a person of normal intelligence. In essence, Cuppe argues that because of his diminished ability to control his impulses, to think in long-range terms, and to learn from his mistakes, he "is not capable of acting with the degree of culpability that can justify the ultimate penalty," id., at 823.

The AAMR and other groups working with the mentally retarded agree with Cuppe. They argue in their friends of the court brief that all mentally retarded people, regardless of their degree of retardation, have substantial cognitive and behavioral disabilities that reduce their level of blameworthiness for a capital offense. Amici Brief for AAMR et al. 5-9, 13-15. Amici do not argue that people with mental retardation cannot be held responsible or punished for criminal acts they commit. Rather, they contend that because of "disability in the areas of cognitive impairment, moral reasoning, control of impulsivity, and the ability to understand basic relationships between cause and effect," mentally retarded people cannot act with the level of moral culpability that would justify imposition of the death sentence. Id., at 4. Thus, in their view, execution of mentally retarded people convicted of capital offenses serves no valid retributive purpose. Id., at 19.

It is clear that mental retardation has long been regarded as a factor that may diminish an individual's culpability for a criminal act. See supra, at 331-333; ABA Standards for Criminal Justice 7-9.3, commentary, at 463; State v. Hall, 176 Neb. 295, 310, 125 N. W. 2d 918, 927 (1964); see generally Ellis & Luckasson, 53 Geo. Wash. L. Rev., at 414. In its most severe forms, mental retardation may result in complete exculpation from criminal responsibility. Moreover, virtually all of the States with death penalty statutes that list statutory mitigating factors include as a mitigating circumstance evidence that "[t]he capacity of the defendant to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was substantially impaired." A number of States explicitly mention "mental defect" in connection with such a mitigating circumstance. The sentencing body must be allowed to consider mental retardation as a mitigating circumstance in making the individualized determination whether death is the appropriate punishment in a particular case.

However, we cannot conclude that all mentally retarded people of Cuppe's ability - by virtue of their mental retardation alone, and apart from any individualized consideration of their personal responsibility - inevitably lack the cognitive, volitional, and moral capacity to act with the degree of culpability associated with the death penalty. Mentally retarded persons are individuals whose abilities and experiences can vary greatly. As the AAMR's standard work, Classification in Mental Retardation, points out: "The term mental retardation, as commonly used today, embraces a heterogeneous population, ranging from totally dependent to nearly independent people. Although all individuals so designated share the common attributes of low intelligence and inadequacies in adaptive behavior, there are marked variations in the degree of deficit manifested and the presence or absence of associated physical handicaps, stigmata, and psychologically disordered states." Classification in Mental Retardation, at 12.

Persons who are mentally retarded are described as having "significantly sub-average general intellectual functioning existing concurrently with deficits in adaptive behavior and manifested during the developmental period." American Association on Mental Deficiency (now Retardation) (AAMR), Classification in Mental Retardation 1 (H. Grossman ed. 1983). To be classified as mentally retarded, a person generally must have an IQ of 70 or below. Id., at 11. Under the AAMR classification system, individuals with IQ scores between 50-55 and 70 have "mild" retardation. Individuals with scores between 35-40 and 50-55 have "moderate" retardation. "Severely" retarded people have IQ scores between 20-25 and 35-40, and "profoundly" retarded people have scores below 20 or 25. Id., at 13. Approximately 89% of retarded persons are "mildly" retarded. Ellis & Luckasson, Mentally Retarded Criminal Defendants, 53 Geo. Wash. L. Rev. 414, 423 (1985).

In addition to the varying degrees of mental retardation, the consequences of a retarded person's mental impairment, including the deficits in his or her adaptive behavior, "may be ameliorated through education and habilitation." Ellis & Luckasson, supra, at 424, n. 54. Although retarded persons generally have difficulty learning from experience, AAMR Brief at 7, some are fully "capable of learning, working, and living in their communities." Id., at 6; see American Association on Mental Deficiency, Monograph 6, Lives in Process: Mildly Retarded Adults in a Large City (R. Edgerton ed. 1984). In light of the diverse capacities and life experiences of mentally retarded persons, it cannot be said on the record before us today that all mentally retarded people, by definition, can never act with the level of culpability associated with the death penalty.

Cuppe urges us to rely on the concept of "mental age," and to hold that execution of any person with a mental age of seven or below would constitute cruel and unusual punishment. Mental age is "calculated as the chronological age of non-retarded children whose average IQ test performance is equivalent to that of the individual with mental retardation." AAMR Brief at 14, n. 6; see D. Wechsler, The Measurement and Appraisal of Adult Intelligence 24-25 (4th ed. 1958). Such a rule should not be adopted today. First, there was no finding below by the judge or jury concerning Cuppe's "mental age." One of Cuppe's expert witnesses, Dr. Orr, testified that he estimated Cuppe's "mental age" to be 6 1/2. That same expert estimated that Cuppe's "social maturity" was that of a 9- or 10-year-old. As a more general matter, the "mental age" concept, irrespective of its intuitive appeal, is problematic in several respects. As the AAMR acknowledges, "[t]he equivalence between non-retarded children and retarded adults is, of course, imprecise." AAMR Brief at 14. The "mental age" concept may underestimate the life experiences of retarded adults, while it may overestimate the ability of retarded adults to use logic and foresight to solve problems. Ibid. The mental age concept has other limitations as well. Beyond the chronological age of 15 or 16, the mean scores on most intelligence tests cease to increase significantly with age. Wechsler 26. As a result, "[t]he average mental age of the average 20 year old is not 20 but 15 years." Id., at 27. See also In re Ramon M., 22 Cal. 3d 419, 429, 584 P.2d 524, 531 (1978) ("[T]he `mental age' of the average adult under present norms is approximately 16 years and 8 months").

Not surprisingly, courts have long been reluctant to rely on the concept of mental age as a basis for exculpating a defendant from criminal responsibility. See, e. g., In re Ramon M., supra, at 429, 584 P.2d, at 531; State v. Schilling, 95 N. J. L. 145, 148, 112 A. 400, 402 (1920); People v. Marquis, 344 Ill. 261, 267, 176 N. E. 314, 316 (1931); Chriswell v. State, 171 Ark. 255, 259, 283 S. W. 981, 983 (1926); cf. Pickett v. State, 71 So.2d 102, 107 (Ala. 1954); see generally Ellis & Luckasson, 53