BRIEF OF AMICUS CURIAE THE AMERICAN ASSOCIATION ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES (“AAIDD”)

IN THE SUPREME COURT FOR THE STATE OF FLORIDA

CASE NO. SC09-262

DONALD DUFOUR,

Petitioner-Appellant,

v.
STATE OF FLORIDA,
Respondent-Appellee.
ON APPEAL FROM THE CIRCUIT COURT OF THE NINTH JUDICIAL
CIRCUIT, IN AND FOR ORANGE COUNTY, FLORIDA

BRIEF OF AMICUS CURIAE THE AMERICAN ASSOCIATION ON
INTELLECTUAL AND DEVELOPMENTAL DISABILITIES (“AAIDD”)

IN SUPPORT OF PETITIONER

George G. Gordon*
DECHERT LLP
Cira Centre, 2929 Arch Street
Philadelphia, PA 19104-2808
Tel: 215.994.4000; Fax: 215.994.2222

Gretchen S. Sween*
DECHERT LLP
300 W. 6th Street, Suite 1850
Austin, Texas 78701
Tel: 512.394.3000; Fax: 512.394.3001

Counsel for Amicus Curiae, AAIDD

*Admitted Pro Hac Vice

TABLE OF CONTENTS

TABLE OF CONTENTS........................................................................................... i
TABLE OF CITATIONS ......................................................................................... ii
IDENTITY AND INTEREST OF AMICUS CURIAE ................................................... 1
SUMMARY OF ARGUMENT.............................................................................................. 2
ARGUMENT .............................................................................................................................. 3

I. Assessing Mental Retardation Claims Under Atkins Requires Use Of
Generally Accepted Clinical Definitions Set Forth By The AAIDD And The
APA .................................................................................................................3
A.
Significant Limitations in Intellectual Functioning Is Measured by
IQ Taking into Consideration the Test’s SEm .........................................4
1.
SEm is inherent to the IQ measurement process...................................6
2.
The upper boundary of IQs indicating mental retardation is
defined by a range, not a hard number..................................................8
B.
Significant Limitations in Adaptive Behavior Are Based on Objective
Measurements, Not Weighed Against Adaptive Strengths...................10
C. Manifestation Should Be Before Age Eighteen .....................................13
II.
Florida’s Standard For Assessing Mental Retardation In Death Penalty
Cases Does Not Comport With The Supreme Court’s Mandate ...............14
CONCLUSION ........................................................................................................................ 20
CERTIFICATE OF SERVICE ................................................................................22
CERTIFICATE OF COMPLIANCE WITH FLA. R. APP. P. 9.210 .....................23

i

TABLE OF CITATIONS
CASES

Federal Cases

Atkins v. Virginia,
536 U.S. 304 (2002)….………………………………………………..passim

City of Cleburne v. Cleburne Living Center,
473 U.S. 432, .................................................................................................13

Hall v. Quarterman,
534 F.3d 365 (5th Cir. 2008) .........................................................................16

Heller v. Doe,
509 U.S. 312 (1993).......................................................................................20

In re Hicks,
375 F.3d 1237 (11th Cir. 2004) .....................................................................10

Kennedy v. Louisiana,
128 S. Ct. 2641 (2008)...................................................................................18

Walker v. True,
399 F.3d 315 (4th Cir. 2005) ...........................................................................9

State Cases

Chase v. State,
873 So. 2d 1013 (Miss. 2004)........................................................................16

Cherry v. Florida,
959 So. 2d 702 (Fla. 2007) ......................................................................15, 18

In re Hawthorne,
105 P.3d 552 (Cal. 2005)...............................................................................16

Jones v. State,
966 So. 2d 319 (Fla. 2007) ......................................................................15, 18

ii

Lambert v. State,
126 P.3d 646 (Okla. Crim. App. 2005) .........................................................11

Louisiana v. Dunn,
831 So. 2d 862 (La. 2002) .............................................................................17

Melican v. Morrisey,
2006 WL 10755465 (Mass. Super. Mar. 13, 2006).......................................17

Commonwealth v. Miller,
888 A.2d 624 (Pa. 2005)................................................................................17

People v. Vidal,
155 P.3d 259 (Cal. 2007).........................................................................16, 17

Docketed Cases

State v. Dufour,
No. 1982-CF-5467 (Fla. 9th Cir. Ct. Dec. 19, 2008) ....................................19

STATUTES AND RULES

§ 921.137, Fla. Stat. .............................................................................................7, 14
Fla. R. Crim. P. 3.203 ..............................................................................................14

OTHER AUTHORITIES

AAIDD, User's Guide: Mental Retardation Definition, Classification and
Systems of Supports 12 (10th ed. 2007)................................................. passim

AAMR, Mental Retardation: Definition, Classification and Systems
Supports 1 (10th ed. 2002) .................................................................... passim

American Association on Mental Deficiency, Mental Retardation Definition,
Classification, and Systems of Supports (Herbert J. Grossman ed., 8th
ed. 1983) ..........................................................................................................9

iii

American Psychiatric Association, Diagnostic and Statistical Manual of
Psychiatric Disorders, Fourth Edition, Text Revision (2000)
[DSM-IV-TR] ........................................................................................ passim

Richard J. Bonnie, The American Psychiatric Association's Resource
Document on Mental Retardation and Capital Sentencing:
Implementing Atkins v. Virginia, 32 J. Am. Acad. Psychiatry Law
304 (2004)......................................................................................................15

Richard J. Bonnie and Katherine Gustafson, The Challenge of Implementing
Atkins v. Virginia: How Legislatures and Courts Can Promote
Accurate Assessments and Adjudications of Mental Retardation in
Death Penalty Cases, 41 U. Rich. L. Rev. 811 (2007) ...................................4

Stanley L. Brodsky & Virginia A. Galloway, Ethical and Professional
Demands for Forensic Mental Health Professionals in the Post-Atkins
Era, 13 J. Ethics & Behav. 3 (2003)..............................................................13

Alfred L. Brophy, Confidence Intervals for True Scores and Retest Scores
on Clinical Tests, 42(6) J. Clinical Psychol. 989 (1986).................................8

James W. Ellis, Mental Retardation and the Death Penalty: A Guide to State
Legislative Issues, 27 Mental & Physical Disability L. Rep. 11 (2003) ...4, 18

Walter Fernald, The Burden of Feeblemindedness, 17 J. Psycho-Aesthenics
87 (1912)........................................................................................................13

James R. Flynn, Tethering the Elephant: Capital Cases, IQ, and the Flynn
Effect, 12 Psychol. Pub. Pol'y & L. 170 (2006)...........................................6, 7

Stephen Greenspan, A Contextualist Perspective on Adaptive Behavior, in
Adaptive Behavior and Its Measurements (Robert L. Schalock ed.,
1999). .............................................................................................................10

Stephen Greenspan & Harvey Switzky, Forty-Four Years of AAMR
Manuals, in What is Mental Retardation?.......................................................1

Alan S. Kaufman & Elizabeth O. Lichtenberger, Assessing Adolescent and
Adult Intelligence (3d ed. 2006) ................................................................6, 10

iv

Robert G. Knight, On Interpreting the Several Standard Errors of the WAIS

R: Some Further Tables 51(5) J. Consulting and Clinical Psychol. 671
(1983)........................................................................................................... 7-8
Robert L. Schalock, et al., The Renaming of Mental Retardation:
Understanding the Change to the Term Intellectual Disability, 45
Intellectual & Developmental Disabilities 116 (2007)....................................1

Michael S. Sorgen, The Classification Process and its Consequences, in The
Mentally Retarded Citizen and the Law 215 (Michael Kindred, et al.,
eds., 1976)......................................................................................................12

James W. Trent, Jr., Inventing the Feeble Mind: A History of Mental Retardation
in the United States (1994)…………………………………………………13

Lois A. Weithorn, Conceptual Hurdles to the Application of Atkins v.
Virginia, 59 Hastings L.J. 1203, 1231 (2008) ...............................................17

v

IDENTITY AND INTEREST OF AMICUS CURIAE

The American Association on Intellectual and Developmental Disabilities

(“AAIDD”), formerly the American Association on Mental Retardation

(“AAMR”),1 has appeared as amicus curiae in numerous cases involving the

meaning of mental retardation, mental retardation diagnoses in the criminal justice

system, and the rights of those with intellectual disabilities under federal and state

law. The AAIDD/AAMR appeared as amicus curiae in the seminal case Atkins v.

Virginia, 536 U.S. 304 (2002). Founded in 1876, the AAIDD is the nation’s oldest

and largest interdisciplinary organization in the field of intellectual and

developmental disabilities. For over 80 years, the AAIDD has educated the public

about the scientific consensus regarding mental retardation.2 Governmental

agencies and courts use the AAIDD definitions to determine whether individuals

1 See Robert L. Schalock, et al., The Renaming of Mental Retardation:
Understanding the Change to the Term Intellectual Disability, 45 Intellectual &
Developmental Disabilities 116 (2007) (explaining why AAIDD changed its name
along with shifting from “mental retardation” to “intellectual disability” without
changing the clinical definition). While clinicians are generally following the
AAIDD’s lead in embracing the term “intellectual disability,” this brief will refer
to “mental retardation,” the term used in Atkins and by the Florida legislature.
2 Since 1910, the AAIDD has published a consensus definition of mental
retardation and information regarding the means by which it is measured. Stephen
Greenspan & Harvey Switzky, Forty-Four Years of AAMR Manuals, in What is
Mental Retardation? at 3-28. In its Diagnostic and Statistical Manuals on Mental
Disorders, the American Psychiatric Association (“APA”) has adopted the
AAIDD’s successive definitions of mental retardation. American Psychiatric
Association, Diagnostic and Statistical Manual of Psychiatric Disorders, Fourth
Edition, Text Revision 48 (2000) (hereafter “DSM-IV-TR”).

1

have mental retardation. See, e.g., Atkins, 536 U.S. at 308 n.3. The AAIDD has a
vital interest in ensuring that (1) all individuals with mental retardation receive the
rights and protections required by law; and (2) courts and administrative agencies
employ accepted scientific principles in assessing mental retardation.

SUMMARY OF ARGUMENT

Atkins v. Virginia, 536 U.S. 304 (2002), prohibits executing capital offenders
who have mental retardation. Moreover, in determining who has mental
retardation and thus who is categorically exempt from the death penalty, Atkins
requires that states apply standards that generally conform to the accepted
scientific definition of mental retardation. That is, Atkins did not leave states free
to define mental retardation; they are instead directed to craft statutes that, at a
minimum, exempt those individuals fairly characterized as having mental
retardation under the AAIDD/AAMR’s and the American Psychiatric
Association’s (“APA”) definitions. 536 U.S. at 317 n.22.

Measuring “intellectual functioning” is just one step in making a diagnosis
of mental retardation. But the mental health profession uniformly accepts that,
when using IQ tests and their resulting scores to measure intellectual functioning,
the standard error of measurement or “SEm” must be applied. In light of the SEm,
for diagnostic purposes, the upper IQ range for mental retardation is 70-75. Id. at

2

309 n.5. Any legal test that applies a rigid IQ cutoff below 75 is inconsistent with
the scientific consensus and, thus, contrary to Atkins’ mandate.

Undoubtedly, there is clinical consensus and Atkins directs the states to rely
on that consensus. Yet some states, like Florida, have strayed from accepted
clinical definitions of mental retardation by, inter alia, imposing an arbitrary IQ
cutoff of 70 for purposes of measuring “significantly subaverage intellectual
functioning,” a required element in the definition of mental retardation. Using an
arbitrary IQ cutoff is inconsistent with Atkins’ mandate and the accepted clinical
consensus.

Further, Florida law reflects a misapprehension of the appropriate way to
assess adaptive behavior deficits. Objective measurements, in conjunction with
social histories, should govern the process of assessing deficits, which should not
be weighed against unrelated strengths.

Therefore, the AAIDD urges this Court to revisit its pronouncements
regarding the assessment of mental retardation under Florida law and to reverse the
Circuit Court’s rulings that erroneously interpreted the relevant evidence here.

ARGUMENT

I.
ASSESSING MENTAL RETARDATION CLAIMS UNDER ATKINS
REQUIRES USE OF GENERALLY ACCEPTED CLINICAL
DEFINITIONS SET FORTH BY THE AAIDD AND THE APA
3

In Atkins v. Virginia, the Supreme Court held that executing individuals with
mental retardation violates the Eighth Amendment of the U.S. Constitution. 536

U.S. 304, 321 (2002). Atkins further directed the states to adopt measures for
ascertaining mental retardation that “generally conform[] to the clinical definitions
set forth” in Atkins itself. Id. at 317 n.22. The Court embraced two clinical
definitions, each of which defines mental retardation as a disability characterized
by (1) significant limitations in intellectual functioning, (2) significant limitations
in adaptive behavior as expressed in conceptual, social, and practical adaptive
skills, and (3) onset before the age of eighteen. See AAMR, Mental Retardation:
Definition, Classification and Systems Supports 1 (10th ed. 2002) [hereafter AAMR
2002]; DSM-IV-TR at 41; see also Atkins, 536 U.S. at 318.3
A.
Significant Limitations in Intellectual Functioning Is Measured by
IQ Taking into Consideration the Test’s SEm
A clinical determination of “signification limitations in intellectual
functioning”—or what Florida statutes refer to as “significant sub-average
intellectual functioning”—involves (1) intellectual “[p]erformance that is at least

3 The AAIDD/AAMR is “the principal professional organization in the field of
mental retardation” and thus “[i]ts definition is highly respected and also reflects
the most current research in the field.” Richard J. Bonnie and Katherine Gustafson,
The Challenge of Implementing Atkins v. Virginia: How Legislatures and Courts
Can Promote Accurate Assessments and Adjudications of Mental Retardation in
Death Penalty Cases, 41 U. Rich. L. Rev. 811, 821 (2007) (urging states to adopt
the AAIDD/AAMR definition). See also James W. Ellis, Mental Retardation and
the Death Penalty: A Guide to State Legislative Issues, 27 Mental & Physical
Disability L. Rep. 11, 13 (2003).

4

two standard deviations below the mean of an appropriate assessment instrument,”
i.e., a standardized IQ test, (2) “considering the standard error of measurement for
the specific assessment instruments used and the instruments’ strengths and
limitations.” AAIDD, User’s Guide: Mental Retardation Definition,
Classification and Systems of Supports 12 (10th ed. 2007) [hereafter AAIDD,
User’s Guide]; AAMR 2002 at 13, 14, 15, 17, 58. Thus, there is a broad consensus
in the field that analyzing IQ scores to determine intellectual performance requires
considering the standard error of measurement.

In diagnosing mental retardation, a clinician first selects from among various
options the standardized intelligence test best suited to the particular circumstances
of the test-taker. If a properly administered test produces a score of approximately
70 or below, the person may be diagnosed with mental retardation, although
evidence of adaptive deficits and age of onset must also be present. Because
individuals in the 65-75 IQ range have similar intellectual functioning to each
other, mental health professionals do not fixate on an exact cutoff when making
diagnoses. Instead, mental health professionals emphasize that individualized
consideration and clinical judgment is critical to assessing intellectual functioning
accurately. See, e.g., AAMR 2002 at 57-59 n.21. And, as reflected in the AAIDD
User’s Guide, when analyzing an IQ score, accepted clinical practice requires
considering the test’s SEm to adjust for inevitable testing errors.

5

1. SEm is inherent to the IQ measurement process
All measurement has some potential for error. For instance, when
measuring vision, the result will be influenced by many factors—including the
tools used to measure the various components of vision, the skill and care of the
measurer, and whether the subject of the measurement is experiencing fatigue,
headache, anxiety, or other distractions. Psychological testing has even greater
potential for error because of the complexity of the phenomenon being measured.
For example, error may be introduced by the examiner making a timing mistake,
failing to record responses accurately, over-prompting, mishandling stimuli objects,
or neglecting to repeat parts of the instructions. See generally Alan S. Kaufman &
Elizabeth O. Lichtenberger, Assessing Adolescent and Adult Intelligence 197 (3d
ed. 2006). Error may also be introduced by the subject’s mood, general health, or
other intangible factors. See, e.g., James R. Flynn, Tethering the Elephant: Capital
Cases, IQ, and the Flynn Effect, 12 Psychol. Pub. Pol'y & L. 170, 171 (2006)
(hereafter “Flynn 2006”); AAMR 2002 at 57.

The SEm is a statistical concept that adjusts for the fact that a precise IQ
score is always an unknown because no measuring tool is devoid of error. The
SEm helps to address the inevitable errors in intelligence testing, thereby
facilitating a more accurate understanding of obtained scores. AAMR 2002 at 58.
Both the AAIDD/AAMR’s and the APA’s definitions of mental retardation stress

6

the necessity and importance of the SEm when considering IQ scores. Id. at 57-58;

DSM-IV-TR at 41-42. The AAIDD summarizes the scientific consensus regarding

the importance of the SEm in assessing IQ scores as follows:

. . . limitations in intellectual functioning are generally thought to be
present if an individual has an IQ test score of approximately 70 or
below. IQ scores must always be considered in light of the standard
error of measurement, appropriateness, and consistency with
administration guidelines. Since the standard error of measurement
for most IQ tests is approximately 5, the ceiling may go up to 75.
This represents a score approximately 2 standard deviations below
the mean, considering the standard error of measurement.

The American Association on Intellectual and Developmental Disabilities,
Frequently Asked Questions on Intellectual Disability and the AAIDD Definition,
http://www.aaidd.org/Policies/faq_mental_retardation.shtml (last visited July 21,
2009) (emphasis added). That is, because of the SEm, “two standard deviations
below the mean” can be as high as 75. AAIDD, User’s Guide at 12; see also §
921.137, Fla. Stat. (2009). Put another way, scores between 65-75 or lower are
consistent with a mental retardation diagnosis. Flynn 2006 at 186.

Taking the SEm into account when interpreting an IQ score is neither new
nor speculative. It constitutes long-standing clinical practice. See, e.g., AAMD,
Mental Retardation Definition, Classification, and Systems of Supports 11 (8th ed.
1983) (explaining that IQ testing is merely “a guideline [that] could be extended
upward through IQ 75 or more, depending on the reliability of the intelligence test
used”); Robert G. Knight, On Interpreting the Several Standard Errors of the

7

WAIS-R: Some Further Tables, 51(5) J. Consulting and Clinical Psychol. 671
(1983) (describing three methods of SEm for WAIS); Alfred L. Brophy,
Confidence Intervals for True Scores and Retest Scores on Clinical Tests, 42(6) J.
Clinical Psychol. 989 (1986). Failing to take the SEm into account constitutes a
clear departure from accepted professional practice in scoring and interpreting any
kind of psychological test, including IQ tests. The importance of the SEm is so
well-established that it would be superfluous to direct experts to take it into
account in a statute governing Atkins evaluations and adjudications. Thus, no
state’s statutory definition expressly refers to the SEm.4

2.
The upper boundary of IQs indicating mental retardation is
defined by a range, not a hard number
The AAIDD/AAMR has long emphasized that the upper boundary of mental
retardation is best described as a range, not as a numerical cutoff: “If the IQ score
is valid, this will generally result in a score of approximately 70 to 75 or below.”
AAMR, Mental Retardation (1992) at 14 n.20. Moreover, the AAIDD/AAMR has
long cautioned that the upper boundary is “flexible” to ensure greater precision
because a range, rather than a hard cutoff, better “reflect[s] the statistical variance
inherent in all intelligence tests and the need for clinical judgment by a qualified

4 See Death Penalty Information Center, State Statutes Prohibiting the Death
Penalty for People with Mental Retardation, http://www.deathpenaltyinfo.org/
state-statutes-prohibiting-death-penalty-people-mental-retardation (last visited July
21, 2009) (listing state death penalty statutes related to mental retardation).

8

psychological examiner.” Id. Further, clinicians have long recognized that the
outer boundary of mental retardation “could be extended upward through IQ 75 or
more, depending on the reliability of the intelligence test used.” AAMD,
Classification in Mental Retardation 11 (Herbert J. Grossman ed., 8th ed. 1983);
DSM-IV-TR at 41-42 (“it is possible to diagnose mental retardation in individuals
with IQs between 70 and 75 who exhibit significant deficits in adaptive behavior.”).
Atkins itself notes that “an IQ between 70 and 75” is considered to reflect the upper
range of intellectual functioning in the most widely accepted clinical definitions of
mental retardation. 536 U.S. at 309 n.5 (citing 2 Kaplan & Sadock’s
Comprehensive Textbook of Psychiatry 2952 (B. Sadock & V. Sadock eds., 7th ed.
2000)).

In short, while mental health experts employ only individualized tests of
intelligence to diagnose the presence of “significantly subaverage general
intellectual functioning,” the experts also accept that there is no “fixed cutoff point
for making the diagnosis of mental retardation,” and no score can be properly
assessed in a vacuum.5 AAMR 2002 at 58. If, after taking the SEm into account,

5 Aside from the SEm, other widely recognized phenomena that affect IQ scores
are the Flynn effect, the practice effect, and mental illness. See AAIDD, User’s
Guide at 21. The AAIDD also emphasizes the importance of each of these effects
in assessing the first criterion for mental retardation. Broadly speaking, the Flynn
effect reflects that IQ scores tend to increase in the general population over time
and thus IQ tests will yield different scores based on when they were normed.
Flynn 2006 at 170. See also Walker v. True, 399 F.3d 315, 322-23 (4th Cir. 2005)

9

an IQ score is in the 70-75 range, and if there is evidence of adaptive deficits and
onset before age 18, then an assessment of mental retardation is warranted.

B.
Significant Limitations in Adaptive Behavior Are Based on
Objective Measurements, Not Weighed Against Adaptive
Strengths
The second prong of the clinical definition requires that an individual have
significant limitations in adaptive behavior. This requirement is designed to ensure
that an IQ score reflects a real-world disability, not merely a testing anomaly.6
This aspect of the clinical inquiry focuses on whether there are skills that the
individual cannot do that someone without the disability can do.7 Like everyone
else, individuals who have mental retardation differ substantially from one another

(remanding because district court failed to consider either the Flynn effect or the
SEm); In re Hicks, 375 F.3d 1237, 1242-43 (11th Cir. 2004) (Birch, J., dissenting)
(identifying the Flynn effect as one reason why stay of execution should have been
granted and the case remanded for further findings). Practice effects refer to the
impact on later test scores of previously administered IQ tests. See Alan S.
Kaufman & Elizabeth O. Lichtenberger, Assessing Adolescent and Adult
Intelligence 202 (3d ed. 2006).
6 The adaptive behavior prong was added to the AAMR definition in 1959 to
reflect the social characteristics of mental retardation and to reduce undue reliance
on IQ scores. AAMR 2002 at 24; Stephen Greenspan, A Contextualist Perspective
on Adaptive Behavior, in Adaptive Behavior and Its Measurements 61, 61 (Robert

L. Schalock ed., 1999).
7 Assessment involves standardized instruments for measuring adaptive behavior,
normed on the general population, along with “a thorough social history,” which
includes “a longitudinal evaluation of adaptive behavior that involves multiple
raters, very specific observations across community environments (especially in
regard to social competence), school records, and ratings by peers during the
developmental process.” AAIDD, User’s Guide at 13, 18, 22.
10

in terms of strengths and weaknesses. Indeed, a fundamental precept in the field of
mental retardation is that “[w]ithin an individual, limitations often coexist with
strengths.” AAMR 2002 at 1. From a definitional perspective, an individual’s
particular strengths are only relevant to assess corresponding weaknesses. DSMIV-
TR at 47; see also Lambert v. State, 126 P.3d 646 (Okla. Crim. App. 2005)
(recognizing that unless evidence of an adaptive strength corresponds to an alleged
adaptive deficit, evidence of the strength is irrelevant and should not be admitted).
That is, weighing strengths against weaknesses is an improper approach to
diagnosing mental retardation.

There is no clinically accepted list of strengths or abilities that preclude a
diagnosis of mental retardation. See DSM-IV-TR (“The diagnostic criteria for
Mental Retardation do not include an exclusion criterion”). Instead, clinicians
consider evidence of deficits in three discernible skill sets: (1) conceptual skills,
which include cognitive abilities, communication, academic skills, the use of
money, and self-direction; (2) social skills, which include interpersonal
relationships, self-esteem, lack of gullibility, and the ability to follow rules; and

(3) practical skills, which are independent living skills such as personal hygiene,
eating, housekeeping, transportation, and occupational skills. AAMR 2002 at 42.
Limitations in adaptive behavior may result from not knowing how to perform a
skill (acquisition deficit) or not knowing when to use a learned skill (performance
11

deficit). Id. at 73-74. Significant deficits in at least one of these three domains
indicates mental retardation, regardless of strengths in other areas. Id. at 76.

The AAIDD recommends that adaptive behavior be assessed primarily
through the use of standardized instruments. See AAMR 2002 at 76. These tests
generally involve interviews with, or questionnaires completed by, third-parties,
such as parents or teachers, who have significant experience interacting with the
individual being evaluated. Id. at 88-90 (describing three common standardized
tests). A qualified respondent will satisfy four criteria: (1) they have almost daily
contact with the individual; (2) their contacts last for extended periods of time; (3)
they have had these contacts within a few months of completing the interview; and

(4) they have had opportunities to observe a variety of skills that the test seeks to
measure. Id. The AAIDD also advises that the results of standardized tests should
be considered in tandem with a social history because best scientific practice
recognizes that “different sources of data” enable “more informed professional
judgment by providing a context” to achieve a comprehensive evaluation of the
person’s functioning. AAIDD, User’s Guide at 18, 22, 86.
Stereotypes and lay assumptions about people with mental retardation can
cloud or distort individual assessment.8 Moreover, many of the skills in the

8 Clinicians have long recognized the insidious effect of stereotyping. See, e.g.,
Michael S. Sorgen, The Classification Process and its Consequences, in The
Mentally Retarded Citizen and the Law 215, 215-16 (Michael Kindred, et al., eds.,

12

clinical definition of adaptive behavior are not relevant in prisons, such as selfdirection,
community resources, and leisure skills. And, notably, a person with
mental retardation is likely to appear to have stronger adaptive behavior in the
structured environment of a correctional facility than in society, thus possibly
inflating scores that would have been indicative of mental retardation in the
community environment.9 For this reason, experts conducting Atkins evaluations
should focus on information relating to the defendant’s adaptive skills before
incarceration.

C. Manifestation Should Be Before Age Eighteen
Evidence of the onset of mental retardation is usually established through a
social history investigation, which includes a thorough inventory of school records,
medical records, and interviews with witnesses (most importantly teachers and

1976); see also City of Cleburne v. Cleburne Living Center, 473 U.S. 432, 454
(1985) (Stevens, J., concurring) (discussing the “history of unfair and often
grotesque mistreatment” noted by experts in the field); James W. Trent, Jr.,

Inventing the Feeble Mind: A History of Mental Retardation in the United States

(1994) (describing the evolving definitions and stereotypes associated with
developmental disability). False stereotyping prompted clinicians in another era to
claim, for example, that “[t]he feeble-minded are a parasitic, predatory class, never
capable of self-support or of managing their own affairs.... They cause unutterable
sorrow at home and are a menace and danger to the community.” Walter Fernald,
The Burden of Feeblemindedness, 17 J. Psycho-Aesthenics 87, 90 (1912). History
has discredited such views; and contemporary science rejects the assumption that
every person with mental retardation possesses the same lack of skills or abilities.
9 See Stanley L. Brodsky & Virginia A. Galloway, Ethical and Professional
Demands for Forensic Mental Health Professionals in the Post-Atkins Era, 13 J.
Ethics & Behav. 3, 7 (2003).

13

school peers) who knew the defendant in the community in which he or she grew
up. AAIDD, User’s Guide at 18-20.

II.
FLORIDA’S STANDARD FOR ASSESSING MENTAL
RETARDATION IN DEATH PENALTY CASES DOES NOT
COMPORT WITH THE SUPREME COURT’S MANDATE
Florida’s three-part statutory definition of mental retardation partially tracks
the definitions promulgated by the AAIDD and in the DSM-IV-TR and endorsed in
Atkins.10 See Fla. R. Crim. P. 3.203; § 921.137, Fla. Stat. Florida’s statutory
definition does not, however, explain how to measure “significantly subaverage
intellectual functioning.” Id. Specifically, the Florida definition contains the first
two elements of the standard AAIDD definition of “significantly subaverage
intellectual functioning,” but does not expressly explain that, in interpreting
standardized IQ tests, clinical practice requires “considering the standard error of
measurement for the specific assessment instruments used and the instruments’
strengths and limitations.” AAIDD, User’s Guide at 12; AAMR 2002 at 13, 14, 15,
17, 58. A visual comparison is instructive:

Fla. R. Crim. P. 3.203; § 921.137, Fla. Stat. AAIDD, User’s Guide at 12; AAMR
2002 at 13, 14, 15, 17, 58
•
performance that is two or more standard
deviations below the mean score
•
on a standardized intelligence test
authorized by the Department of
•
performance that is at least two
standard deviations below the mean
•
of an appropriate assessment
instrument [i.e., a standardized IQ

10 Florida’s statutory definition, adopted in 2001, is based on the AAIDD/AAMR’s
older 1983 definition of mental retardation. See FL Staff An., S.B. 238, 2/14/2001.

14

Children and Family Services in Rule
65B-4.032 of the Florida Admin. Code
test]
•
considering the SEm for the specific
assessment instruments used and the
instruments’ strengths and
limitations

The fact that Florida does not include an explicit reference to the SEm
should not mean that under Florida law “significantly subaverage general
intellectual functioning” can be based on an arbitrary IQ cutoff or that the SEm can
be ignored. To the contrary, the SEm must be taken into account if an assessment
regarding mental retardation is to “generally conform[] to the clinical definitions”
as Atkins requires. 536 U.S. at 317 n.22. Imposing a correlation between
“significantly subaverage general intellectual functioning” and a specific IQ cutoff
conflicts with accepted scientific practice. See, e.g., Richard J. Bonnie, The
American Psychiatric Association’s Resource Document on Mental Retardation
and Capital Sentencing: Implementing Atkins v. Virginia, 32 J. Am. Acad.
Psychiatry Law 304, 305-06 (2004) (stating the APA’s position that “incorporation
of a specific cutoff score is inappropriate”).

Yet that is precisely how Florida courts have interpreted the state’s statutory
definition. See Cherry v. Florida, 959 So. 2d 702 (Fla. 2007); Jones v. State, 966
So. 2d 319, 329 (Fla. 2007). The approach applied in cases such as Cherry and
Jones, in which the Court applied an arbitrary IQ cutoff of 70 without properly
accounting for the SEm, is at odds with Atkins and the standard scientific

15

understanding of mental retardation. The use of an arbitrary cutoff is contrary to
the U.S. Supreme Court’s mandate that states, while free to establish their own
procedural rules, must use standards that adhere to the scientific and clinical
definitions of mental retardation adopted by the AAIDD and the DSM-IV-TR.
Atkins, 536 U.S. at 317 n.22; see also Hall v. Quarterman, 534 F.3d 365 (5th Cir.
2008) (holding district court unreasonably denied Atkins claim in part because
decision was based on state court’s erroneous interpretation of defendant’s IQ
score). Indeed, under the current construction of Florida’s statutory definition,
persons who would be considered to have mental retardation under accepted
scientific and clinical standards are being deemed eligible for execution.

Other states have properly rejected the notion of a rigid IQ cutoff in making
mental retardation determinations, including California, Mississippi, Louisiana,
Pennsylvania, and Massachusetts. See, e.g., People v. Vidal, 155 P.3d 259 (Cal.
2007) (rejecting bright-line IQ cutoff and interpreting the state’s statutory
definition of mental retardation to require a complete factual analysis to determine
whether a defendant has “subaverage general intellectual functioning”); In re
Hawthorne, 105 P.3d 552 (Cal. 2005) (same); Chase v. State, 873 So. 2d 1013,
1028 (Miss. 2004) (explaining that, under prevailing definitions approved in Atkins,
mental retardation “may, under certain conditions, be present in an individual with
an IQ of up to 75” and emphasizing that IQ alone “does not determine mental

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retardation”); Louisiana v. Dunn, 831 So. 2d 862, 884, 887 (La. 2002) (ordering
hearing on mental retardation where defendant had IQ score of 71 to consider the
SEm and other factors); Commonwealth v. Miller, 888 A.2d 624, 629-31 (Pa. 2005)
(recognizing importance of the SEm in assessing IQ scores); Melican v. Morrisey,
2006 WL 10755465 (Mass. Super. Mar. 13, 2006) (analyzing IQ scores, quoting
AAMR materials regarding the SEm, and concluding that plaintiff qualified for
disability benefits with IQ score of 75). Further, courts in other jurisdictions have
recognized that statutes defining mental retardation need not explicitly mention the
SEm in connection with measuring “subaverage general intellectual functioning,”
because the role of the SEm in interpreting IQ scores and assessing intellectual
functioning is widely accepted scientific practice. See, e.g., Vidal, 155 P.3d at 267
(discussing statutory definition of mental retardation virtually identical to
Florida’s).

The divergent constructions of virtually identical statutory language in
different jurisdictions is profoundly troubling, especially considering the context.
These differences mean that the same offender could be eligible for execution in
one state but not in another. See Lois A. Weithorn, Conceptual Hurdles to the
Application of Atkins v. Virginia, 59 Hastings L.J. 1203, 1231 (2008) (“[A]s the
comparison between Florida’s and California’s use of standardized IQ tests
suggests, there are noteworthy inconsistencies in the ways in which state courts are

17

using these tests. This result is disturbing in light of the dramatic consequences of
the application of these tests in the Atkins context.”). This disparate application of
Atkins, based on different constructions of the same statutory language reputedly
based on the same clinical definitions, offends the Eighth Amendment, which
demands consistent and non-arbitrary application of the death penalty. See
Kennedy v. Louisiana, 128 S. Ct. 2641, 2665 (2008) (ensuring against “arbitrary
and capricious application” of the death penalty requires that its use be
restrained).11

This Court, in suggesting that Atkins gave unfettered discretion to the states
to define mental retardation, has promulgated an incorrect statement of law. See
Jones, 966 So.2d at 327. Under Atkins, Florida is not free to define mental
retardation in contravention to the clinical consensus. Instead, in the death penalty
context, Florida’s definition of mental retardation must conform to standard
clinical understanding. Atkins, 536 U.S. at 317 n.22. Yet with regard to both the
interpretation of IQ scores and the proper assessment of adaptive deficits, Florida
has gone off course. See, e.g., Cherry, 959 So. 2d 702 (incorrectly concluding that
Florida’s statutory language that refers to “two or more standard deviations below
the mean score” is synonymous with a raw IQ score of 70 or below); Jones, 966

11 See, e.g., Ellis, supra, n.3; Richard J. Bonnie, The American Psychiatric
Association’s Resource Document on Mental Retardation and Capital Sentencing:
Implementing Atkins v. Virginia, 32 J. Am. Acad. Psychiatry & L. 304, 305-06
(2004).

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So.2d 319, 327-28 (improperly rejecting expert testimony regarding adaptive
behavior before age 18 and focusing on evidence of defendant’s routines in prison
and adaptive strengths instead of deficits).

Ostensibly following this Court’s lead, the trial court in this case has strayed
even further afield from commonly accepted clinical understanding. With respect
to Mr. Dufour, the trial court erred by improperly using the SEm to conclude that
IQ scores below 70 were really above the state’s arbitrary cutoff of 70. State v.
Dufour, No. 1982-CF-5467, 9-10 (Fla. 9th Cir. Ct. Dec. 19, 2008). Properly
accounting for the SEm, Mr. Dufour’s scores show significantly subaverage
intellectual functioning. The trial court also erred in assessing Mr. Dufour’s
adaptive deficits, improperly weighing Mr. Dufour’s adaptive strengths against
unrelated deficits and unsound assumptions about his alleged “street smarts.” Id.
at 10-18. Further, the court made numerous assumptions about Mr. Dufour’s
mental capacity that are contrary to the clinical judgments of appropriately
qualified and experienced experts in mental retardation. For instance, the court
gave undue weight to evidence regarding Mr. Dufour’s behavior in prison, id. at
13-14; gave insufficient weight to credible opinions of trained clinicians in the best
position to assess mental retardation and relied unduly on lay testimony, id. at 5-10;
and made a finding about age-of-onset contrary to the great weight of the evidence,
id. at 18-19.

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CONCLUSION

The U.S. Supreme Court has correctly observed that diagnosing mental
retardation is less complex than many forms of mental illness. Heller v. Doe, 509

U.S. 312, 321-22 (1993). In diagnosing mental retardation, there are objective
measures of intellectual functioning and objective means to assess deficits in
adaptive skills and vast consensus with the mental health profession as to how best
to assess mental retardation. The rulings under review conflict with professionally
accepted scientific standards. Specifically, the rulings do not properly consider the
SEm in interpreting Mr. Dufour’s IQ scores or the range of scores relevant to
assessing his intellectual functioning. Nor do the rulings reflect standard scientific
methodology for determining deficits in adaptive behavior. Additionally, the
court’s rulings do not account for the substantial evidence of onset before age 18.
To the extent that these rulings correctly interpret Florida law, Florida law is at
odds with both the Atkins decision and contemporary scientific understanding in
terms of (1) the erroneous notion that “significantly subaverage intellectual
functioning” correlates to an arbitrary IQ cutoff of 70 and (2) the misconceptions
as to how to measure adaptive behavior deficits. Therefore, the AAIDD
respectfully asks that this Court reverse the rulings below that denied Mr. Dufour’s
motion for determination of mental retardation as a bar to execution.
20

Date: ___________, 2009 Respectfully submitted,

DECHERT LLP
George G. Gordon (admitted PHV)
Cira Centre
2929 Arch Street
Philadelphia, PA 19104-2808
Tel: 215.994.4000
Fax: 215.994.2222
Gretchen S. Sween (admitted PHV)
300 W. 6th Street
Suite 1850
Austin, Texas 78701
Tel: 512.394.3000
Fax: 512.394.3001

Counsel for Amicus Curiae, AAIDD

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CERTIFICATE OF SERVICE

I HEREBY CERTIFY that true and correct copies of the foregoing motion

were served by first-class mail on ___________, 2009 upon the following persons:

Maria D. Chamberlin
Assistant CCRC
Capital Collateral Regional Counsel – Middle Region
3801 Corporex Park Drive
Suite 210
Tampa, Florida 33619

Scott A. Brown
Assistant Attorney General
Office of the Attorney General
Concourse Center 4
3507 E. Frontage Road, Suite 200
Tampa, Florida 33607-7013

Dick K. Jucknath
Assistant State Attorney
Office of the State Attorney
415 North Orange Avenue
PO Box 1673
Orlando, Florida 32801

Donald Dufour
DOC # 061222
Union Correctional Institution
7819 NW 228th Street
Raiford, FL 32026

Gretchen S. Sween (admitted PHV)
DECHERT LLP
300 W. 6th Street
Suite 1850
Austin, Texas 78701
Tel: 512.394.3000; Fax: 512.394.3001

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CERTIFICATE OF COMPLIANCE WITH FLA. R. APP. P. 9.210

Undersigned counsel hereby certifies that this brief complies with the font

requirements of Florida Rule of Appellate Procedure 9.210(a)(2) in that the printed

brief is in Times New Roman, 14-point font and otherwise comports with the Rule.

Gretchen S. Sween (admitted PHV)
DECHERT LLP
300 W. 6th Street
Suite 1850
Austin, Texas 78701
Tel: 512.394.3000
Fax: 512.394.3001

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