INTELLIGENCE

1
INTELLIGENCE
2

• The global capacity to act purposefully, to think
  rationally, and to deal effectively with the
  environment

3
THE HISTORY OF INTELLIGENCE TESTING

• Francis Galton and Anthropometry
• English scientist 1822-1911
• Cousin of Darwin
• human measurement
• Differential psychology
• Studies individual differences in physical,
  personality, and intellectual characteristics
• James McKeen Cattell (1860-1944)
• Mental test

4

• Alfred Binet, Theodore Simon, and the IQ Test
• Binet-Simon scale in 1905
• Alfred Binet (1857-1911)
• Theodore Simon (1873-1961)
• Mental age
• William Stern (1871-1938)
• Recommended a ratio
• Lewis Terman
• Eliminated the decimal point by multiplying by
  100
• Intelligence quotient (IQ)
• Mental age/chronological age) x 100 IQ

5

• Lewis Terman and American Intelligence Testing
• Henry Goddard (1866-1957)
• Lewis Terman (1877-1956)
• Revised test for Americans
• Stanford-Binet Intelligence Scale
• Army Alpha Test and Army Beta Test
• Otis Lennon Mental Abilities Tests and Armed
  Forces Qualification Test

6

• David Wechsler and the Deviation IQ
• Get dumber as you get older?
• Deviation IQ
• Compares persons IQ score with the mean score of
  their peers
• Mean of peers 100
• Wechsler-Bellevue Intelligence Scale
• Wechsler Intelligence Scale for Children (WISC)
• Wechsler Adult Intelligence Scale (WAIS)
• Wechsler Preschool and Primary Scale of
  Intelligence (WPPSI)

7
ISSUES IN INTELLIGENCE TESTING

• Standardization
• Establishment of norms
• Uniformity in how test is administered
• Normal curve
• Mean of 100 and Standard deviation of 15

8
(No Transcript)
9

• Reliability of Intelligence Tests
• The degree in which test gives consistent results
• Correlation coefficient
• Test-retest method
• Alternate form
• Split half method

10

• Stanford-Binet and Wechsler at least .90 out of
  1.0
• IQ can change over time
• Increases through adolescences and levels off at
  about the age 20

11

• The Validity of Intelligence Tests
• Measures what it suppose to measure.
• Content validity
• Content of test is a fair and representative
  sample of what test is suppose to measure
• Criterion validity
• Whether test actually measures for a skill or
  ability (criterion) that will be demonstrated
  later.
• Sometimes called predictive validity
• Construct validity
• Test is actually measuring the theoretical
  construct it claims to measure

12

• Get the same scores on both test
• College Admissions Tests
• SAT .41
• GPA .52
• Both .58

13
GROUP DIFFERENCES IN IQ

• American Blacks score ten to fifteen points lower
  than American whites
• Asian Americans score slightly higher than whites

14

• Between-group differences Are the tests culture
  fair?
• Black English
• Stanford-Binet translated into black English

15

• Culturally Unbiased Tests
• culture-free tests in the 40s
• culture-fair tests in the 50s
• Raven Progressive Matrices
• Same problem
• Holland and India

16
(No Transcript)
17

• Between-group differences Heredity or
  environment?
• Within-group heritability
• Matching for the environment
• Same social-economic backgrounds
• Blacks adopted by whites
• Is it possible to completely match the
  environments?

18
(No Transcript)
19

• Stereotype Threat and IQ Test Performance
• Awareness of the stereotype might effect your
  performance
• Self-fulfilling prophecy
• Blacks taking test
• Children at school
• Asian-American women and math

20
THEORIES OF INTELLIGENCE

• Factor Analytic Theories of Intelligence or
  psychometric approach
• Spearmans Theory of General Intelligence
• Charles Spearman (1863-1945)
• Factor Analysis
• Determines the degree of correlation between
  performances on various tasks to determine the
  extent to which they reflect particular
  underlying characteristic, which are known as
  factors.
• g factor a general intelligence factor
• s factor accounts for a less than perfect
  correlation of 1.00

21
(No Transcript)
22
(No Transcript)
23

• Thurstones Theory of Primary Mental Abilities
• Louis Thurstone (1887-1955)
• Seven Factors Primary Mental Abilities
• Reasoning
• Word fluency
• Perceptual speed
• Verbal comprehension
• Spatial visualization
• Numerical calculation
• Associative memory

24

• Horn and Cattells Two-Factor Theory of
  Intelligence
• John Horn and Raymond Cattell (1966)
• Fluid Intelligence
• Reflects reasoning ability, memory capacity, and
  speed of information processing
• Crystallized intelligence
• Reflects knowledge acquired through schooling and
  in everyday life.

25

• Beyond IQ A different approach
• The Triarchic Theory of Intelligence
• Robert Sternberg (2000)
• Componential intelligence or analytic
• Book smarts
• Experiential intelligence or creative
• Ability to combine different experiences in
  insightful ways to solve novel problems based on
  past experience
• Contextual intelligence or practical
• Function in practical everyday social situations
  street smarts
• Tacit knowledge Practical know-how gleaned from
  everyday experience

26

• The Theory of Multiple Intelligences
• Howard Gardner (1983)
• Linguistic intelligence
• Logical-mathematical intelligence
• Spatial intelligence
• Musical intelligence
• Bodily-kinesthetic intelligence
• Intrapersonal intelligence
• Interpersonal intelligence

27
NATURE, NURTURE AND INTELLIGENCE

• SOME POLITICAL ISSUES
• Why educate them if they have lower IQ since
• Immigration policy
• The Bell Curve
• Head Start

28
(No Transcript)
29

• GENETIC FACTORS
• Genetic Transmission
• Phenotype and Genotype
• Observable traits
• Traits specified in the genes
• Siamese cats
• Himalayan rabbit
• Heredity and changeability
• Phenylketonuria or PKU

30
(No Transcript)
31

• Genetics and IQ
• Children and parents
• .47
• Siblings?
• .47

32

• Twin studies
• Identical twins
• .86
• Fraternal twins
• .60
• Identical twins reared apart
• .75

33
(No Transcript)
34

• Adopted children
• Colorado Adoption Project (CAP)
• IQ scores more correlated with biological parents
  than adopted parents
• .28 versus .15
• More so as the child gets older

35

• ENVIRONMENTAL FACTORS
• IQ scores correlate more for fraternal twins than
  siblings.

36

• Impoverished environments
• Canal boat employees in England and rural
  Kentucky mountain residents
• Negative correlation between age and IQ
• School closures
• 6 pts for every school missed

37

• Enriched environments
• East Tennessee
• 1930-1940 Scores rose 10pts 82 to 92 pts
• Venezuelan Intelligence Project
• Carolina Abecedarian Project

38

• Worldwide improvement in IQ scores
• 3pts. per decade
• Flynn effect
• Hard to account for this change genetically
• Why?

39

• HERITABILITY
• Nature and nurture
• Heritability ratio (H)
• How much do individuals differ in their phenotype
  from each other?
• What proportion of this variability can be
  attributed to genetic variation?
• .40 to .70
• .50 or 50
• Within a population, not an individual
• Not a fixed number either