Differences in Intelligence

1
Differences in Intelligence
2
NATURE (genetic influence)

• Twins intelligence scores are virtually as
  similar to those of the same person taking a test
  twice.
• Identical twins show a greater correlation in
  intelligence scores than fraternal twins.
• Brain scans show twins have very similar gray
  matter volume

3
NURTURE (environmental influence)

• Malnutrition can influence cognitive development
• Head Start and other programs increase childrens
  school readiness.
• Intelligence scores tend to rise during the
  school year and drop off in the summer months.
  Argument for year round schooling.
• Identical twins reared apart have a lower
  intelligence correlation than those reared
  together.

4
The Flynn Effect

• Overall intelligence testing has been improving
  this is called the Flynn Effect (Graph pg. 447)
• The avg. persons intelligence score 80 years ago
  is equal to a 76 today.
• This trend has been observed in many countries.
• What could cause the Flynn effect?

5
The Flynn Effect
6
Explaining the Flynn Effect

• Better nutrition
• Better education
• More stimulating environments
• Smaller families

7
Nature vs. Nurture Intelligence summary

• Nature vs. Nurture-Intelligence YouTube

8
Ethnic Similarities and Differences

• Genetics research reveals that under the skin,
  the races are remarkably alike.
• Individual differences within races are much
  greater than the differences between races.
• White and Black infants score equally well on
  infant intelligence measures.

9
Ethnic Similarities and Differences

• The Disturbing Facts
• Racial groups differ in their average
  intelligence scores
• Avg. IQ for Whites 100
• Avg. IQ for Blacks 85
• Avg. IQ for other minorities between 85 and 100
• Although this gap is shrinking slowly, it still
  persists.
• Are these differences due to genetics or the
  environment?

10
Environmental Explanations for Gap

• Self fulfilling prophecies- Gender/race-
  Stossell
• Student beliefs about themselves-Black/white doll
  
• experiment and Brown decision. Separate but
  Equal-pt.1
• Teacher beliefs about student abilities. The
  Pygmalion Effect and the Power of Positive
  Expectations (1st 300)
• Teachers unconscious bias when selecting who can
  take upper level classes. CMS study on 6th to
  12th grade English scores.
• Nutrition and scores.
• In group pressures to not "act white" Uncle Toms.

11
Environmental Explanations for IQ Gap

• Prejudice has negative influence on achievement.
• Ogbu study suggesting that minority groups in all
  cultures score lower on intelligence tests
  produced by majority culture.
• Fewer role models.
• Less of a perception of school as a means to
  better life.
• Fewer family financial concerns.
• (Role of TV films).
• Look at Tom the Dancing Bug
• How Priming Impacts Your Performance

12
Gender Differences

• Gender differences in intelligence is minor
• Girls are better spellers
• Girls are more verbally affluent
• Girls surpassed boys in memory for picture
  associations
• Girls are sensitive to touch, taste and odor
• Girls are better at detecting emotions
• Boys outnumber girls in underachievement - More
  boys in special education classes
• Boys are better at math problem solving
• Boys spatial ability is superior

13
Stereotype Threat

• Stereotype threat a self-confirming concern
  that one will be evaluated based on a negative
  stereotype. (self-fulfilling prophecy) p. 465
• Ex. Women score higher on math tests when they
  are not tested alongside of men
• Ex. Blacks score higher when tested by a black
  test administrator rather than a white test
  administrator

14
Take the Australian and Chitling Tests

• Take tests

15
Cultural Bias in testing

• Is there cultural bias in testing?

16
What is meant by bias?

• Tests detect differences caused by cultural
  experiences
• Ex. Question What is a Tobaggon?
• And regional bias
• A cup is paired with a saucer or you buy
  insurance to protect your property
• AP Psych 2009 exam drivers license. Q Why is
  this bias for someone from Tokyo, Shanghai,
  Seoul.
• If this is the case, are intelligence tests a
  vehicle for discrimination?- show quotes from
  original creators of SAT, Stanford-Binet (most
  influential standardized tests in history

17
Bias in Testing

• TAKE STANDARDIZED TEST OF QUESTIONS THAT HAVE
  BEEN ELIMINATED DUE TO BIAS.
• Q. WHY WERE THE FOLLOWING QUESTIONS CONSIDERED
  BIAS
• ETS (Collegeboard) goes to great lengths to
  create unbias exams today. Ex.- being on the
  rubric team, roomate from Shaghai China, my
  selection.

18
Who succeeds on the SAT?

• Studies show that upper class white male
  northeasterners tend to perform better than any
  other group. Why?
• Test was created by white, upper-class males.
  What does being like the test creators have
  anything to do with your ability to perform well
  on a test?
• High socio economic status vocabulary
• Test preparation -
• Taking test several times -
• Any others?

19
Evidence supporting SAT Bias

• Females have higher HS GPAs but males perform
  better on SATs
• Over 1400 SAT scores (1600 scale)
• 29 from upper class
• 24 from middle class
• 14 from lower class
• High School performance among these
  particular students has opposite numbers.

20
Wake Forest Ends testing

• No SATs for Wake Forest University YouTube
• Wake Forest example lends doubt to the SATs
  McClatchy
• A New Book Argues Against the SAT - NYTimes.com
• Review Institutional Discrimination and
  Standardized Testing/ Homogeneous Grouping.