Race and IQ

1. Race and IQ Historical misuses and contemporary issues

2. 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

3. A long (and mostly sordid) history

4. 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)

5. 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

6. 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”

7. 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

8. 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

9. Goddard (continued) • 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.

10. 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 Sample items

11. 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

12. WAIS Popularity WAIS

13. 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%)

14. 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)

15. SAT to IQ conversion table

16. Relationship between SAT and IQ • 1. For SAT scores before 1996 IQ = (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."

17. WAIS Verbal Subtests

18. WAIS Performance Subtests Picture Completion Picture Arrangement Block Design Object Assembly Digit-Symbol Substitution

19. Interpreting IQ scores

20. Interpreting IQ scores (normal curve)

21. The Flynn Effect (1995 data) • IQ scores tend to rise 3 points every 10 years

22. 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)

23. IQ and Education

24. IQ and education/occupation (same data)

25. IQ tests’ strengths and weaknesses

26. The IQ racial gap

27. Possible explanations for the gap • The tests are bad • Genetic differences • Environmental differences

28. 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)

29. Chitling Intelligence Test (Dove, 1971) CB 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.

30. Black Intelligence Test of Cultural Homogeneity • 100-item multiple-choice test, based on items drawn from Black culture • Sample Questions • 1. Alley Apple is a) brickb) piece of fruitc) dogd) horse • 2. CPT means a standard of a) timeb) tunec) taled) twist • 3. Deuce-and-a-quarter is a) moneyb) a carc) a housed) dice A, A, B

31. 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

32. Cultural bias data

33. Are the tests (racially) biased? • Argument 3: The tests have different construct validity for Blacks and Whites

34. 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

35. IQ and Education (1990)

36. 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

37. 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

38. Are the tests (racially) biased? • Argument 7: The tests are neutral but the norms are inappropriate In other words: Separate (rather than national) norms should be used to eliminate racial bias [recent example] Logical outcome (if taken to logical conclusion): • Race group differences would be eliminated, but… • Scores would have little relevance to racial justice, and • Scores would not allow tracking of group outcomes/disparities

39. Possible explanations for the gap • The tests are bad (no empirical support for current racial bias!) • Genetic differences • Environmental differences

40. The heritability of IQ

41. 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)

42. The genetic position A. Assumptions 1. Intelligence is polygenetic (Gottesman’s model postulates 5 genes) 2. Intelligence is normally distributed 3. Very low intelligence is produced by genetic abnormalities B. Evidence 1. Average IQ correlation of identical twins is .86 2. Identical twins, fraternal twins, siblings, and parent-child IQ correlations all higher than that of unrelated persons 3. Parent-child correlations are higher for biological vs adopted parents 4. When siblings are reared together, IQ correlations are higher for biological siblings than for adopted siblings 5. The high correlations in IQ scores resist change over time 6. Many genetic abnormalities have been proven to cause lower IQ a. Turner’s syndrome b. Fragile X syndrome c. PKU

43. The environmentalist position A. Assumptions 1. Genetics alone cannot account for the normal range of IQ 2. Intelligence is not necessarily normally distributed (tests are designed to yield a normal distribution) B. Evidence 1. 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 correlations 3. Assortative mating 4. Adoptive parent-child correlations are higher than unrelated adults and children 5. Studies of environmental influences on IQ show that a. Low birth weight decreases IQ b. Malnutrition decreases IQ c. Family background affects IQ d. Pressure to achieve increases IQ e. Birth order and family size affect IQ f. Amount and quality of schooling affects IQ

44. But is the racial gap genetic? Hard to determine due to environmental differences.

45. Is the racial gap genetic? Many controversial “studies”

46. Between-group vs within-group variation

47. 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

48. 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.”

49. Possible explanations for the gap • The tests are bad (no empirical support) • Genetic differences (data mixed, no consensus) • Environmental differences

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