1. Chapter 9: Intelligence & Language
Amber Gilewski
Tompkins Cortland Community College

2. The Evolution of Intelligence Testing
Sir Francis Galton (1869)
Hereditary Genius
Alfred Binet and Theodore Simon (1905)
Binet-Simon Intelligence Scale
Mental age
Lewis Terman (1916)
Stanford-Binet Intelligence Scale
Intelligence Quotient (IQ) = MA/CA x 100
created by William Stern
David Wechsler (1939)
Wechsler Adult Intelligence Scale

3. Factor Theories of Intelligence
Intelligence is made up of a number of mental abilities (factors)
Spearman’s g factor
General intelligence
s factor represents specific intelligence
Thurstone’s eight specific factors
Primary mental abilities

4. Theories of Intelligence
Sternberg’s triarchic theory
(analytical, creative, practical)
Gardner’s multiple intelligences
(musical, bodily kinesthetic, logical-mathematical, linguistic, spatial, interpersonal, intrapersonal, naturalist, existential)
Goleman’s emotional intelligence: understanding emotions in self and others; regulating emotions

5. Approximate Distribution of IQ Scores

6. Differences in Intellectual Functioning
Socioeconomic and Ethnic Differences
Consideration of social class
Lower-class U.S. children score 10 – 15 IQ points lower than middle- and upper-class
Consideration of ethnicity
Impact of social class
Asian Americans more likely to graduate high school and complete college

7. Do Intelligence Tests Contain Cultural Biases?
Tests may measure familiarity with dominant middle-class culture
Culture-free Intelligence Tests
Cattel’s Culture-Fair Intelligence Test
Goodenough’s Draw-A-Person test
European American children outperform African American children on “culture-free” test
Steele’s stereotype vulnerability
Ethnic differences vs. social class

8. Figure 9.17 Genetics and between-group differences on a trait

9. Gender Differences in Intelligence Tests
Intelligence tests do not show overall differences in cognitive ability
Girls superior to boys in verbal ability
Boys excel in visual-spatial ability
Boys tend to score higher on math tests
Group scores represent greater variation within the group than between the groups

10. Genetic Influences on Intelligence
Kinship studies
IQ scores of identical twins are more alike than for any other pairs
Twin Studies
IQ scores of MZ twins reared together have higher correlation than MZ twins reared apart
Adoption Studies
Stronger relationship between IQ scores of adopted children and their biological parents than between children and adoptive parents

11. Heritability of Intelligence
Heritability is between 40% and 60%
About half the difference between your IQ score and the IQ scores of other people can be explained by heredity
Environment is also important
Being reared together is related to IQ similarities
Cumulative deprivation hypothesis
Concept of “reaction range”

12. Findings of Studies of the Relationship between IQ Scores and Heredity

13. Environmental Influences on Intelligence
The Flynn Effect
Home Environment
Important predictor of IQ scores - ages 3 to 8
Education
Enriched early environments (Head Start)
Western world – IQ scores rose substantially between 1947 and 2002
Impact of social and cultural factors
Changes also demonstrated in subpopulations
Educational gap between races in U.S. is narrowing

14. The Complex Web of Factors That Affect Intellectual Functioning