The Bell Curve

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The Bell Curve

• Evaluation Critique

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Where Does It Go Wrong?

• Claim that intelligence is fixed stable
• Claim that ethnic differences are genetic
• Technical issues
• AFQT not good IQ test
• regression analysis, w/out goodness of fit
• Definition of intelligence as g
• Sleight of hand in moral argument

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Evidence Intelligence not Fixed

• Flynn Effect

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Ravens Matrices
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Flynn Effect
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Flynn Effect
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Ethnicity and Race

• Within group vs. between group variation
• Social Inequality Test Scores
• Genes vs. Environment recent twin adoption
  studies
• Social Inequality Stress
• Stereotype Threat

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Genetic Variability Between-Group Differences
Iowa soil
Nevada soil
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Inequality IQ / Achievement Scores
Country High Scores Low Scores
U.S. Whites Whites Blacks Latinos
Great Britain English Irish, Scottish
Northern Ireland Protestants Catholics
Australia Whites Aborigines
New Zealand Whites Maoris
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Inequality IQ / Achievement Scores
Country High Scores Low Scores
South Africa English Afrikaaners
Belgium French Flemish
Israel Jews Western Jews Arabs Eastern Jews
India High caste Low caste
Czech Slovaks Gypsies
Japan Non-Burakumin Burakumin
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Turkheimer 2003 Twin Studies

• Environmental influence greater for children in
  poor families
• Genes set upper limit
• Environment determines whether limit reached
• If you have a chaotic environment, kids
  genetic potential doesnt have a chance to be
  expressed.

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Capron DuymeFrench Adoption Study 1

• High-SES ? high-SES IQ 120
• High-SES ? low-SES IQ 108
• Low-SES ? low-SES IQ 92
• Low-SES ? high-SES IQ 104

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Capron DuymeFrench Adoption Study 2

• Sample of abused / neglected infants, adopted
  between age 4 and 6
• IQ at adoption 77
• IQ 9 years later
• Farmers laborers 86
• Middle class 92
• Upper class 98

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Enrichment Effects
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Social Inequality Stress

• Height U.S. men 5 9
• Dutch men 6 1
• Subordinate primates
• glucocorticoid-cascade hypothesis
• allostatic load ? hypercortisolemia
• depression social isolation
• atrophy of hippocampal neurons
• poor ovarian function
• compromised immune functioning
• ? stunted growth accelerated aging

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Stereotype ThreatClaude Steele

• Whites blacks take GRE-like test
• ½ told measures intelligence ½ told
• developing test of problem-solving
• White scores same in both conditions
• Black scores equal to whites in developing test
  condition
• Black scores lower in measures intelligence
  condition

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Stereotype Threat

• Women score lower when test measures math
  ability
• Asian women taking math test
• femaleness primed ? score lower
• Asianness primed ? score higher

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Stereotype Threat

• Golf study
• -- Blacks out-play whites in test of athletic
  ability
• -- Blacks out-played by whites in test of
  athletic intelligence
• Basketball vertical leap study
• -- Whites cant jump when experimenter is Black
  !!!

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Ethnicity and Race

• Within group vs. between group variation
• Social Inequality Test Scores
• Genes vs. Environment recent twin adoption
  studies
• Social Inequality Stress
• Stereotype Threat

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What Harm Does It Do?

• Racist view of ethnic differences
• Downplays influence of social environments
• Narrow theory of intelligence fixed
  unchangeable
• Social Darwinism not socio-biology
• Moral sleight of hand

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Moral Sleight of hand

• Two sets of ideas, joined from Galton to Murray
  Herrnstein
• IQ should be measured as purely abstract
  operations performed on tasks uncontaminated by
  Real World
• IQ scores can be viewed as the source of virtue,
  morality, ambition, drive.

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The Bell Curve (p. 21)
This identification of IQ with attractive
human qualities in general is unfortunate and
wrong. This thing we know as IQ is
important but not a synonym for human excellence.
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Herrnstein (1971)
It is only when able and energetic
individuals can rise and displace the dull and
sluggish ones that there can be sorting out of
people according to inherited differences.
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The Bell Curve
The difference between people of low
cognitive ability and the rest of society may be
put in terms of a metaphor Everyone has a moral
compass, but some of those compasses are more
susceptible to magnetic storms than others. (p.
543)
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What Good Does It Do?

• Danger of accelerating stratification of American
  society
• Sorting process in Americas schools
• High-tech society may not have a place for
  everyone
• Challenges naïve liberal view that all
  differences environmental
• Challenges view that wealth status are rewards
  for hard work poverty just punishment for
  laziness

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Raise Key Moral Question

• If its not someones fault that he is less
  intelligent than others, why should he be
  penalized in his income and social status?
• (p. 527)

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Tension Animating Bell Curve

• They approve of IQ-based sorting stratification
• But this process destroying the social values
  they cherish undermining democracy

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Question Basic Values

• Thrasymachus (Plato) justice is the ideology
  of strong?
• H M Meritocracy is the ideology of the
  cognitive elite?

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A Place for Everyone
At the heart of our thought is the quest
for human dignity. The central measure of
success for this government, as for any other, is
to permit people to live lives of dignity
( p. 551) The broadest goal is a society
in which people can find, and feel they have
found, a valued place for themselves. (p. 535 )
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Thomas Hobbes

• The value or worth of a man is, as of all
  other things, his price that is to say, so much
  as would be given for the use of his power And
  as in other things so in men, not the seller but
  the buyer determines the price.
• To value a man at a high rate is to honor him,
  at a low rate is to dishonor him.
• -- Leviathan, 1651

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A Valued Place

• A low-IQ underclass, with no valued place, is a
  creation of modern society

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Charles Darwin

• If the misery of our poor be caused not by the
  laws of nature, but by our institutions, great is
  our sin.
• Voyage of the Beagle