Intellectual Assessment in Atkins Cases Intellectual Assessment in Atkins Cases and Use of School Diagnosesand Use of School Diagnoses

Frank M. GreshamFrank M. Gresham

Louisiana State UniversityLouisiana State University

Symposium: Death Penalty Court Decisions and Mental Retardation Classification and Research, Presented at the 2009 APA Annual Convention, August 7, 2009, Toronto, Ontario CANADA

Commonwealth of VirginiaCommonwealth of VirginiaVirginia’s Definition of Mental RetardationVirginia’s Definition of Mental Retardation

A disability originating before age of 18 years characterized A disability originating before age of 18 years characterized by:by:– Significantly subaverage intellectual functioning as Significantly subaverage intellectual functioning as

demonstrated by performance on a standardized measure of demonstrated by performance on a standardized measure of intellectual functioning that is intellectual functioning that is at least 2 standard deviations at least 2 standard deviations below the meanbelow the mean

– Significant limitations in adaptive behavior as expressed in Significant limitations in adaptive behavior as expressed in conceptual, social, and practical adaptive skillsconceptual, social, and practical adaptive skills

– Assessment of intellectual functioning shall include Assessment of intellectual functioning shall include administration of at least one standardized measure generally administration of at least one standardized measure generally accepted by the field of psychological testing accepted by the field of psychological testing

– With respect to intellectual functioning, the Virginia statute With respect to intellectual functioning, the Virginia statute provides that “the Commissioner shall maintain provides that “the Commissioner shall maintain an exclusive list an exclusive list of standardized measures of intellectual functioning generally of standardized measures of intellectual functioning generally accepted by the field of psychological testing”accepted by the field of psychological testing”***Tests move on and off this list quite frequently

Ruling:Ruling:U.S. District Court U.S. District Court

Eastern District of VirginiaEastern District of VirginiaWalker v TrueWalker v True

Petitioner has failed to show by preponderance of evidence Petitioner has failed to show by preponderance of evidence that he was mentally retarded before age of 18that he was mentally retarded before age of 18

Petitioner has shown that he sufferers from below average Petitioner has shown that he sufferers from below average mental intelligencemental intelligence

Petitioner has failed to show by preponderance of evidence Petitioner has failed to show by preponderance of evidence that the scored 2 standard deviations below the mean on an that the scored 2 standard deviations below the mean on an approved measure of intellectual functioningapproved measure of intellectual functioning

Only scores of 70 or less are considered 2 standard deviations Only scores of 70 or less are considered 2 standard deviations below the meanbelow the mean

Petitioner argues that his WISC-R score of 76 and WAIS-III Petitioner argues that his WISC-R score of 76 and WAIS-III score of 80 are both 2 standard deviations below the mean in score of 80 are both 2 standard deviations below the mean in light of the light of the standard error of measurement, practice effect, standard error of measurement, practice effect, and Flynn Effect.and Flynn Effect.

Court considered these explanations “speculative”Court considered these explanations “speculative” Decision overturned by Fourth Circuit Court of AppealsDecision overturned by Fourth Circuit Court of Appeals

Interpretive Issues in Intellectual Interpretive Issues in Intellectual AssessmentAssessment

Nature of Intellectual FunctioningNature of Intellectual Functioning Flynn EffectFlynn Effect Practice EffectsPractice Effects Measurement ErrorMeasurement Error School “Diagnoses”School “Diagnoses”

Nature of IntelligenceNature of Intelligence

Fluid versus Crystallized Intelligence: Liquid or Mineral?Fluid versus Crystallized Intelligence: Liquid or Mineral? Walker’s IQ DataWalker’s IQ Data Crystallized IntelligenceCrystallized Intelligence

– Woodcock-Johnson-III (33 years) Verbal=78Woodcock-Johnson-III (33 years) Verbal=78– WISC-R (11-6 years) WISC-R (11-6 years) VIQ= 70 VIQ= 70– WISC-R (14-9 years) WISC-R (14-9 years) VIQ= 75 VIQ= 75– WAIS-III (26 years) WAIS-III (26 years) VIQ= 87 VIQ= 87**– WAIS-III (27 years) WAIS-III (27 years) VIQ= 80 VIQ= 80– MdnMdn= 78= 78

Fluid Intelligence (33 years)Fluid Intelligence (33 years)– CTONI-68CTONI-68– Raven- 63Raven- 63– GAMA- 61GAMA- 61– MdnMdn= 63= 63*Scoring errors admitted in Court*Scoring errors admitted in Court

Flynn EffectFlynn Effect

Well-established finding of 0.3 point increase in mean IQ per yearWell-established finding of 0.3 point increase in mean IQ per year Findings hold for U.S. and worldwideFindings hold for U.S. and worldwide Norms become less accurate over timeNorms become less accurate over time WAIS-III particularly susceptible to increase (normative problems)WAIS-III particularly susceptible to increase (normative problems) Flynn’s Deposition in Walker caseFlynn’s Deposition in Walker case**

– WAIS-R (1978) & WAIS-III (1995) +5.24 pointsWAIS-R (1978) & WAIS-III (1995) +5.24 points– WISC-III (1989) & WAIS-III (1995) +1.64 pointsWISC-III (1989) & WAIS-III (1995) +1.64 points– WAIS-III (1989) & SB-IV (2001) +3.16 pointsWAIS-III (1989) & SB-IV (2001) +3.16 points– WAIS-III (1989) & WISC-IV (2001) +0.76 pointsWAIS-III (1989) & WISC-IV (2001) +0.76 points

WAIS-III inflates scores compared to contemporarily normed testsWAIS-III inflates scores compared to contemporarily normed tests ““WAIS-III score of 79 (obtained in 2000) should be interpreted as a WAIS-III score of 79 (obtained in 2000) should be interpreted as a

score of 75 (7 years X 0.3=2.10+2.34 WAIS-III adjustment.”score of 75 (7 years X 0.3=2.10+2.34 WAIS-III adjustment.”**

*Dates reflect when test was normed, not when it was released

Flynn Effect & MMR DiagnosesFlynn Effect & MMR DiagnosesKanaya, Scullin, & Ceci (2003)Kanaya, Scullin, & Ceci (2003)

(Based on almost 9,000 referrals to SPED)(Based on almost 9,000 referrals to SPED)

Size of Flynn Effect in MMR –Borderline Range of IQSize of Flynn Effect in MMR –Borderline Range of IQ– WISC-R-WISC-R: 79.0-80.2WISC-R-WISC-R: 79.0-80.2– WISC-R-WISC-III: 78.4-73.9WISC-R-WISC-III: 78.4-73.9– WISC-III-WISC-III: 78.5-78.1WISC-III-WISC-III: 78.5-78.1– WISC-III-WISC-IV 78.5-74.5*WISC-III-WISC-IV 78.5-74.5*

Changes in MMR Classification Because of Flynn EffectChanges in MMR Classification Because of Flynn Effect– Change from WISC-R to WISC-III almost DOUBLED rate of MMR Change from WISC-R to WISC-III almost DOUBLED rate of MMR

classification (19% to 34%)classification (19% to 34%) Impact of Flynn Effect on Borderline IQ RangesImpact of Flynn Effect on Borderline IQ Ranges

– IQ 71-75 on WISC-RIQ 71-75 on WISC-R– 3-fold increase in IQs 66-70 on when retested with WISC-III (14% to 3-fold increase in IQs 66-70 on when retested with WISC-III (14% to

40%)40%)

*Not part of the Kanaya et al. (2003) study

Take Away Message on Flynn EffectTake Away Message on Flynn Effect

Intelligence has Intelligence has notnot changed over time changed over time Changes in measured IQ reflect creeping obsolescence of normsChanges in measured IQ reflect creeping obsolescence of norms Level of intelligence reflects Level of intelligence reflects accuracy accuracy of norms; not accuracy of IQof norms; not accuracy of IQ IQ scores inextricably, directly, & entirely dependent on normsIQ scores inextricably, directly, & entirely dependent on norms Flynn Effect & absolute level of intelligence is empirically mootFlynn Effect & absolute level of intelligence is empirically moot Prosecutors may argue that IQ of 70 20 years ago would be IQ 76 Prosecutors may argue that IQ of 70 20 years ago would be IQ 76

todaytoday Defense may argue that IQ of 71 today would be IQ 65 20 years from Defense may argue that IQ of 71 today would be IQ 65 20 years from

nownow By logical extension, norms could become so tough that everyone By logical extension, norms could become so tough that everyone

would qualify as being mentally retardedwould qualify as being mentally retarded IQ scores must be interpreted in terms of when norms were collectedIQ scores must be interpreted in terms of when norms were collected

Practice Effects & IQ Test ScoresPractice Effects & IQ Test Scores

Practice effects occur on IQ tests that are repeatedly administered Practice effects occur on IQ tests that are repeatedly administered (5-8 points)(5-8 points)

Shorter the retest interval, the greater the practice effectsShorter the retest interval, the greater the practice effects Low initial scores on a test tend to increase on retestLow initial scores on a test tend to increase on retest Differences difficult to interpret when initial test & retest measures Differences difficult to interpret when initial test & retest measures

are differentare different Differences in results may depend on item content in the testDifferences in results may depend on item content in the test Differences between repeated testing results may be due to Differences between repeated testing results may be due to

differences in motivation, interest, or the “stakes” of testingdifferences in motivation, interest, or the “stakes” of testing ““Petitioner has failed to present evidence that an adjustment in Petitioner has failed to present evidence that an adjustment in

test scores due to practice effects would be anything other than test scores due to practice effects would be anything other than speculation.”speculation.”

Experts have not made courts understand that practice effects are Experts have not made courts understand that practice effects are real, not speculative, particularly in death penalty cases where real, not speculative, particularly in death penalty cases where defendants are repeatedly testeddefendants are repeatedly tested

Role of Measurement ErrorRole of Measurement Error

What is the most appropriate estimate of error in death penalty cases?What is the most appropriate estimate of error in death penalty cases?– Internal consistency estimates?Internal consistency estimates?– Stability estimates?Stability estimates?– Both?Both?

Consistency estimates typically yield Consistency estimates typically yield less measurement errorless measurement error Consistency: How reliable is this individual’s score on an IQ test on a Consistency: How reliable is this individual’s score on an IQ test on a

given day?given day? Stability: Will this individual will obtain a similar score if retested with Stability: Will this individual will obtain a similar score if retested with

the same test in the future?the same test in the future? Fourth Circuit refused to use the standard error of measurement to Fourth Circuit refused to use the standard error of measurement to

lower IQ scores in Atkins cases due to the lower IQ scores in Atkins cases due to the “inherent speculation of “inherent speculation of using the standard error of measurement to lower an IQ score when it using the standard error of measurement to lower an IQ score when it could just as likely be used to raise an IQ score.”could just as likely be used to raise an IQ score.”

Experts have not made courts understand band of error concept & Experts have not made courts understand band of error concept & probability of true scoreprobability of true score

State’s expert refers consistently in his report to the “standard error of measure” (sic)

School Diagnoses:School Diagnoses:Some Atkins Case ExamplesSome Atkins Case Examples

Daryl Atkins-VirginiaDaryl Atkins-Virginia– IQ=59IQ=59– Not diagnosed as MR in schoolNot diagnosed as MR in school– Long, pervasive history of academic underachievementLong, pervasive history of academic underachievement

Kevin Green-VirginiaKevin Green-Virginia– IQ=71IQ=71– Not diagnosed as MR by schoolsNot diagnosed as MR by schools– Diagnosed as speech/language impaired by D.C. schoolsDiagnosed as speech/language impaired by D.C. schools– Retained 3 times in schoolRetained 3 times in school– Referred to SPED at age 13 yearsReferred to SPED at age 13 years– Long, pervasive history of academic underachievementLong, pervasive history of academic underachievement– EXECUTEDEXECUTED

Darick Walker-VirginiaDarick Walker-Virginia– IQ=63-78IQ=63-78– Not diagnosed as MR by schoolsNot diagnosed as MR by schools– Diagnosed has specific learning disability (SLD), later EDDiagnosed has specific learning disability (SLD), later ED– Lost in U.S. District Court, appealed to U.S. Court of Appeals (won)Lost in U.S. District Court, appealed to U.S. Court of Appeals (won)

School DiagnosesSchool Diagnoses(continued)(continued)

Johnny L. Neal -AlabamaJohnny L. Neal -Alabama– IQ=65IQ=65– Not diagnosed as MR by schools (attended Louisiana schools)Not diagnosed as MR by schools (attended Louisiana schools)– Diagnosed as “Low Borderline” by schoolsDiagnosed as “Low Borderline” by schools– Director of SPED testified that schools did not use MR label except in Director of SPED testified that schools did not use MR label except in

cases of severe MRcases of severe MR– Admitted to Hammond State School for the Mentally Retarded (MR Admitted to Hammond State School for the Mentally Retarded (MR

diagnosis)diagnosis)– Admitted to East State Hospital (2 suicide attempts + MR)Admitted to East State Hospital (2 suicide attempts + MR)– Death sentence commuted to life imprisonment without paroleDeath sentence commuted to life imprisonment without parole

School “Diagnoses”School “Diagnoses”

All 4 cases never had diagnosis of mental retardation by schoolsAll 4 cases never had diagnosis of mental retardation by schools Prosecutors often take this as Prosecutors often take this as prima facie prima facie evidence that MR was not evidence that MR was not

exhibited during developmental period (prior to age 18)exhibited during developmental period (prior to age 18) Most cases have a specific learning disability diagnosis which courts Most cases have a specific learning disability diagnosis which courts

view as not MRview as not MR Schools reluctant, if not totally unwilling, to assign MR label for MMR, Schools reluctant, if not totally unwilling, to assign MR label for MMR,

particularly for African-American individualsparticularly for African-American individuals

IQ<75IQ<75MacMillan, Gresham, Siperstein, & Bocian (1996)MacMillan, Gresham, Siperstein, & Bocian (1996)

SLD 44%M=68

MR 14%M=63

The labyrinth of IDEA: School decisions for referred studentswith subaverage general intelligence. American Journalon Mental Retardation, 101, 161-174.

IQ<70IQ<70Kanaya et al. (2003)Kanaya et al. (2003)

SLD48.1%MR

48.5%

M=64M=66

Summary of School “Diagnoses”Summary of School “Diagnoses”

Schools use the SLD label as a catchall category for SPED Schools use the SLD label as a catchall category for SPED servicesservices

Students with MMR 3 times more likely to be classified as Students with MMR 3 times more likely to be classified as SLDSLD

Students with MMR also more likely to be classified as SLIStudents with MMR also more likely to be classified as SLI Students with MMR just as likely to be deemedStudents with MMR just as likely to be deemed ineligible ineligible as as

MMRMMR All All AtkinsAtkins cases are adults & school history becomes critical cases are adults & school history becomes critical

(onset prior to age 18 years)(onset prior to age 18 years) Courts don’t “get” schools & SPED processCourts don’t “get” schools & SPED process

What’s the Take Away Message?What’s the Take Away Message?

Courts do not understand the nature of intelligence and how an Courts do not understand the nature of intelligence and how an individual might obtain different scores on different tests at individual might obtain different scores on different tests at different times different times

Psychometric True Score (IQ) vs. Absolute True Score (DNA)Psychometric True Score (IQ) vs. Absolute True Score (DNA) Courts consider the Flynn Effect to be a theory rather than factCourts consider the Flynn Effect to be a theory rather than fact Courts consider practice effects to be speculative rather than factCourts consider practice effects to be speculative rather than fact Courts do not understand concept of measurement error & Courts do not understand concept of measurement error &

regression artifactsregression artifacts Courts often take failure of schools to diagnose defendants as MR Courts often take failure of schools to diagnose defendants as MR

to indicate absence of MRto indicate absence of MR COURTS JUST DON’T UNDERSTAND THE CONCEPT OF MMR AND COURTS JUST DON’T UNDERSTAND THE CONCEPT OF MMR AND

THE “CLOAK OF COMPETENCE”THE “CLOAK OF COMPETENCE” Psychological evidence in these cases often not be very Psychological evidence in these cases often not be very

convincingconvincing