Race and IQ

Historical misuses and contemporary issues

Race and IQ

The history of IQ testing

A brief introduction to IQ tests

Race-group differences A summary of the issue Possible explanations

Test bias Genetic differences Environmental differences

A long (and mostly sordid) history

Craniometry (1860)

Pierre Brocca Believed brain size=intelligence Interesting methods… Concluded:

“The brain is larger in mature adults than in the elderly, in men than women,…in superior races than in inferior races”

(Brocca quoted by Gould, 1978, p. 44)

Alfred Binet

Lawyer, self taught in psychology, studied under Charcot (who also influenced Freud)

Asked by French government to create a test to identify students who would benefit from remedial education

Along with Theodore Simon, created first widely-used standardized test of intelligence, the Simon-Binet Scale

The birth of the IQ test

France legislates mandatory primary education in 1882 Government requests test to identify students who need “special ed.”

Alfred Binet publishes (with Theodore Simon) the first widely-used standardized IQ test (with 30 subtests) the Simon-Binet Scale (1905)

Digit repetition Sentence completion Point to an object in a picture Conscious recognition of resemblances

How are a fly, an ant, a butterfly, a flea alike? In what way are a newspaper, a label, a picture alike?

Recognition of food Moral judgment

Revised scale published in 1908 14 tests retained, 9 dropped, 7 modified, 33 added If 75-90% of children in age group pass, it was assigned that age level Rejected notion of “IQ”

Henry Goddard

Translated Simon-Binet into English (1908) Distributed 22,000 copies of translated test

across the U.S. Set up first laboratory to study mental retardation in New Jersey:

     Vineland Training School for Feebleminded Girls & Boys  Strong advocate of eugenics 1912 book The Kallikak Family: A Study in the Heredity of

Feeble-mindedness original article summary and analysis

Goddard (continued) Wanted to prevent the breeding of feebleminded people

hesitated to promote compulsory sterilization, even though convinced it would solve problem

suggested "colonies" where the feeble-minded could be segregated

Established an intelligence testing program on Ellis Island in 1913 rejects 80% of “pre-identified” immigrants as "feeble-minded"

83% of all Jews 80% of the Hungarians 79% of the Italians 87% of the Russians.

resulted in an exponential increase in deportations

The Immigration Restriction Act (1924-1965)  Strongly influenced by American eugenics' efforts

restricted numbers of immigrants from undesirable racial groups (including Jews). 

Upon signing, President Coolidge commented, "America must remain American." 

Publicized race-group differences on Army IQ tests and claimed Americans were unfit for Democracy

One of many scientists (including Galton and Terman) that inspired scientific racism movement in Europe & U.S.

Goddard (continued)

Robert Yerkes

Founded first non-human primate research lab

Chaired committee that created the Army Alpha and Beta intelligence tests used in U.S. during World War I

David Wechsler

Obtained Ph.D. in 1925

Chief psychologist at Bellevue Psychiatric Hospital from 1932-1967

Developed several intelligence tests, including Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Intelligence Scale for Children (WISC).

Born in Rumania, emigrated to U.S. at age 6

Worked as a psychological examiner in army during WWI

WAIS Popularity

WAIS

Defining Intelligence

“Global capacity to act purposefully, to think rationally, and to deal effectively with the environment” (David Wechsler)

1987 survey of 1020 experts on intelligence Abstract reasoning (99.3%) Problem-solving ability (97.7%) Capacity to acquire knowledge (96.0%) Memory (80.5%) Adaptation to environment (77.2%)

Intelligence vs other types of tests

Aptitude tests measure a narrow range of ability

Achievement tests measure what you know or what you learned/achieved

Question: What is the SAT?

Answer: A multiple aptitude test (related to intelligence)

SAT to IQ conversion tableSATV+M

IQ 15 SD %ile   SAT

V+MIQ 15 SD %ile

1600 152.18 99.975   1010 109.46 73.587

1590 151.45 99.970   1000 108.74 71.985

1580 150.73 99.964   990 108.01 70.338

1570 150.00 99.957   980 107.29 68.647

1560 149.28 99.949   970 106.56 66.916

1550 148.56 99.940   960 105.84 65.149

1540 147.83 99.929   950 105.12 63.347

1530 147.11 99.916   940 104.39 61.516

1520 146.38 99.901   930 103.67 59.659

1510 145.66 99.883   920 102.94 57.780

1500 144.94 99.863   910 102.22 55.883

1490 144.21 99.840   900 101.50 53.972

1480 143.49 99.813   890 100.77 52.052

1470 142.76 99.782   880 100.05 50.128

Relationship between SAT and IQ

1. For SAT scores before 1996IQ = (0.126 x SAT combined) + (-.4.71E - 5 x SAT combined x SAT combined) + 40.063 (Detterman and Frey, Case Western Reserve Univ.)

2. For SAT scores from 1996 -2004 IQ =(0.095 X SAT Math) + (0.003 X SAT Verbal) + 50.241 Scores for SAT were "re-centered" in 1996, raising the average SAT back to 500 (Detterman and Frey, Case Western Reserve Univ.)

“SAT to IQ conversion is an inexact science, particularly for SAT's under 900. The chart's creator writes: "The lowest point of reference was the theoretical average IQ of high school students being 110 and the current average SAT I V+M (verbal + math) score being 1019. Everything below that is extrapolation. Also note that the decimal places give the impression that the numbers are more precise than they really are."

WAIS Verbal Subtests

WAIS Performance Subtests

Picture Completion

Picture Arrangement

Block Design

Object Assembly

Digit-Symbol Substitution

Interpreting IQ scores

Interpreting IQ scores (normal curve)

The Flynn Effect (1995 data)

IQ scores tend to rise 3 points every 10 years

Does IQ matter?

How can we tell?

Data indicate IQ and school performance (GPA)

r=.50 for elementary and high school students r=.40 for college students

IQ and years of education (r=.50, see next slide)

IQ and occupational attainment (r=.50)

Likely due to very high correlation (r= mid .60s) between education and occupation

IQ and job performance (rs= .27 to .47)

IQ and Education

IQ and education/occupation (same data)

IQ tests’ strengths and weaknesses

The IQ racial gap

Possible explanations for the gap

The tests are bad

Genetic differences

Environmental differences

Are the tests (racially) biased?

Argument 1: IQ tests yield race-group differences, hence the tests are biased

Argument 2: The test item content is culturally biased

Example: “What should you do when a child smaller than you begins to fight with you?” (comprehension)

Chitling Intelligence Test (Dove, 1971)

A "handkerchief head" is:  

(a) a cool cat(b) a porter(c) an Uncle Tom(d) a hoddi(e) a preacher

Many people say that "Juneteenth" (June 19) should be made a legal holiday because this was the day when:

(a) the slaves were freed in the USA(b) the slaves were freed in Texas(c) the slaves were freed in Jamaica(d) the  slaves were freed in California(e) Martin Luther King was born(f) Booker T. Washington died.

CB

Black Intelligence Test of Cultural Homogeneity 100-item multiple-choice test, based on items drawn from Black

culture Sample Questions

1. Alley Apple isa) brickb) piece of fruitc) dogd) horse

2. CPT means a standard ofa) timeb) tunec) taled) twist

3. Deuce-and-a-quarter isa) moneyb) a carc) a housed) dice A, A, B

Are the culture-specific tests valid?

Useful for building self-esteem But low predictive validity

Low correlation between “Black” IQ Test and achievement (Language =. 33, Math=.18)

Students in MR classes did no better on the “Black” IQ Test than on the WISC

Cultural bias data

Are the tests (racially) biased?

Argument 3: The tests have different construct validity for Blacks and Whites

Are the tests (racially) biased?

Argument 4: The tests have different/inadequate predictive validity for Blacks and Whites

B.I.T.C.H. correlations: Language =. 33 Math=.18

IQ and Education (1990)

Are the tests (racially) biased?

Argument 5: The tests have language bias because they are in standard English and many Blacks grow up speaking a Black dialect

Are the tests (racially) biased?

Argument 6: The tests are neutral but the examiners are biased

Evidence:

25 of 29 studies published prior to 1995 found no significant relationship between the race of the examiner and Black children’s scores

Are the tests (racially) biased?

Argument 7: The tests are neutral but the norms are inappropriateIn other words: Separate (rather than national) norms should be used to eliminate racial bias [recent example]

Logical outcome (if taken to logical conclusion):

1. Race group differences would be eliminated, but…2. Scores would have little relevance to racial justice, and3. Scores would not allow tracking of group

outcomes/disparities

Possible explanations for the gap

The tests are bad (no empirical support for current racial bias!)

Genetic differences

Environmental differences

The heritability of IQ

Historical and current understanding

Heritability debate has a long, controversial history In the 1960's Arthur Jensen fueled debate with heritability estimate

of .8 The Bell Curve (1994) by Herrnstein and Murray

Contemporary consensus

Evidence does exist for high heritability, but

Environmental factors are also important Studies show heritability = .4 to .8 (best estimate probably .7)

High heritability does not discount environmental influence. Consider vocabulary

So are psychological factors (e.g., Carol Dweck’s work)

The genetic positionA. Assumptions

1. IQ is polygenetic (Gottesman’s model postulates 5 genes)2. IQ is normally distributed3. Very low IQ is produced by genetic abnormalities

B. Evidence1. Average IQ correlation of identical twins is .862. Identical twins, fraternal twins, siblings, and parent-child IQ correlations all higher than that of unrelated persons3. Parent-child correlations are higher for biological vs adopted parents4. When siblings are reared together, IQ correlations are higher for biological siblings than for adopted siblings5. The high correlation in #1 resists change over time6. Many genetic abnormalities have been proven to cause lower IQa. Turner’s syndromeb. Fragile X syndromec. PKU

The environmentalist positionA. Assumptions

1. Genetics alone cannot account for the normal range of IQ2. IQ is not necessarily normally distributed (tests are designed to yield a

normal distribution)

B. Evidence1. IQ corrs of identical and fraternal twins raised together are higher than

for those raised apart.2. Fraternal twins IQ correlations are higher than siblings’s IQ correlations3. Assortative mating4. Adoptive parent-child correlations are higher than unrelated adults and

children5. Studies of environmental influences on IQ show that

a. Low birth weight decreases IQb. Malnutrition decreases IQc. Family background affects IQd. Pressure to achieve increases IQe. Birth order and family size affect IQf. Amount and quality of schooling affects IQ

But is the racial gap genetic?

Hard to determine due to environmental differences.

Is the racial gap genetic?

Many controversial “studies”

Between-group vs within-group variation

What we know about IQ heritability

There is strong evidence of within-group heritability Laws of heredity produce regression to the mean There is a certain environment by gene interaction

What we know about IQ heritability (cont.)

1987 survey of 1020 intelligence experts The difference is entirely due to environmental variation: 15%. The difference is entirely due to genetic variation: 1% The difference is a product of genetic and environmental variation: 45%. The data are insufficient to support any reasonable opinion: 24%. No response (or not qualified): 14%.

Robert Sternberg: "science isn't done by majority rule"

APA 1997 task force: “It is sometimes suggested that the Black/White differential in psychometric intelligence is partly due to genetic differences. There is not much direct evidence on this point, but what little there is fails to support the genetic hypothesis.”

Charles Murray: “Actually, there is no direct evidence at all, just a wide variety of indirect evidence, almost all of which the task force chose to ignore.”

Possible explanations for the gap

The tests are bad (no empirical support)

Genetic differences (data mixed, no consensus)

Environmental differences

Environmental Factors

Social class and home environment matter Attribution of intelligence matters (Dweck) Motivation and test taking stills matters Stereotype threat matters Interventions matter

Scores have narrowed in past 30 years

Social Class matters

Bell curve, 1994

Family Factors and IQ

R2=.0576

Home environments

Environmental Factors

Social class and home environment matter Attribution of intelligence matters (Dweck) Motivation and test taking stills matters Stereotype threat matters Interventions matter

Stereotype threat matters

Stereotype threat literature

Steele and Aronson (1995)

Ryan and Anthony (2006)

Interventions matter

Recent NY Times article: Who gets to graduate?

The Culture of Poverty (Kutner, 1975)

Blaming the victim (Ryan, 1976)

Four Steps to Blaming the Victim

1. Identify a social problem

2. Study those affected by the problem to discover how they are different from those who are not affected by the problem.

3. Define the difference as the cause of the problem itself

4. Create a humanitarian action (social service) program to correct the problem cause (from #3)

Real-world example:http://www.whitehouse.gov/news/releases/2005/03/20050307-5.html

Blaming the (IQ) victim

1. Social problem: African American children underperforming

(relative to Whites) on IQ tests

2. Study those affected by the problem to discover how they are different from those who are not affected by the problem

1. Black families more likely to be less educated2. Black families more likely to have poor study spaces3. Black children more likely to be unmotivated to do well on tests4. Black children less likely to associate education with success

3. Define the difference as the cause of the problem itself

Black children under-perform on IQ tests because Black families don’t value education

4. Create a humanitarian action (social service) program to correct the problem cause

?

Blaming the (IQ) victim, continued