Chapter 9: Intelligence and Its Measurement
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What is intelligence?
Definitions
Intervening Variables
Factor Analytic Approaches
Alternative Approaches
Binet Scales
Wechsler Scales
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Definitions
Galton
Binet
Wechsler
Piaget
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Nature of Intelligence
Innate vs. Environment
Heritability index
Twin studies have demonstrated good evidence of genetic influence
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Genetic Evidence
Twin, family, and adoption studies
Biological mothers, tested at the time of delivery: IQ = 86.
13 years later, their children had an IQ of 107
Genetic Evidence
French studies have shown increases in IQ of children adopted into families with a higher
SES
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Stability of Intelligence
Is there a decline in IQ across age cohorts?
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Cross-sectional studies
Intergenerational effects
Longitudinal studies
Cross-sequential studies
Origins of Intelligence
Heredity
Influence of genetic and environmental variables is well established
Environmental Factors
Origins of Intelligence
Early malnutrition or exposure to rubella can impair a child’s mental functioning
Origins of Intelligence
Mother-infant interactions and quality of the home environment are the best predictors of a
child’s performance on IQ and language tests 4-years later
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Origins of Intelligence
Relationship between a child’s IQ at age 4, age 13, and risk factors
– Maternal level of education
– Maternal mental illness
– Minority status
– Family size
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Interacting Variables
Personality factors
Measurement Process
Gender roles
Socioeconomic Status (SES)
Culture
Cumulative Experiences
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Conventional Intelligence Tests
Measure general level of intellectual performance
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Functions
Preliminary screening
Academic
Identification of mentally retarded
Clinical
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Limitations of IQ Scores
Validity is a tests ability to assess the construct it is trying to assess
IQ is what IQ tests measure
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IQ Tests & Cultural Bias
Crisco is a:
a. patent medicine
b. disinfectant
c. toothpaste
d. food product
Culture free tests carry hidden biases
Categorize geometric stimuli according to color and shape
– Liberians have no experience with abstract geometrical figures taken out of context
and reproduced on paper
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Factor Analytic Approaches
Based on statistical analysis of test scores (factor analyses)
Finding common dimensions of intelligence
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Two factor Theory (g-s)
General factor “g”
– electrochemical mental energy, abstract reasoning (facility of thinking)
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Specific factors "s"
Spearman later accepted there were “group factors”
Objective is to obtain tests high in "g"
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Examples
Binet-Simon scale (high in verbal)
Raven's Progressive Matrices
Catell's Culture Fair Intelligence Test
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Multi-Factor Approaches
Advanced by Thorndike (1921)
– social
– concrete
– abstract
Current theory accepts that there are a number of broad group factors
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Primary Mental Abilities
(Thurstone, 1938)
Primary Mental Abilities Test (PMAT)
Identified 12 group factors of intelligence
Also acknowledged second order factors
– Verbal comprehension, Word Fluency, Number, General reasoning, Space,
Associated memory, Perceptual Speed
Hierarchical Theory
(Vernon, 1950)
Alternative schema
1 - General factor "g"
2 - Major group factors
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verbal-educational and practical-mechanical
3 - Minor group factors
– verbal and numerical, mechanical, spatial subfactors
4 - Specific factors
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Structure of Intellect Model (Guilford, 1967)
Three dimensions
1. Operations
2. Contents
3. Products
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Raymond B. Catell (1971) factor analytic model
fluid intelligence
– non-verbal, culture free
– mazes
crystallized intelligence
– exposure and education
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Alternative Approaches
Information Processing (Luria, 1966)
Two basic styles (separate but complementary)
– simultaneous (parallel)
– successive (sequential) information is individually processed in sequential fashion
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Multiple Intelligences
(Gardner, 1983)
Multiple abilities
Musical, artistic, social
Abilities not measured by current tests
Linguistic
– using words effectively
Logical-Mathematical
– reasoning, calculating
Spatial
– think in terms of physical space
Musical
– show sensitivity to rhythm and sound
Body-Kinesthetic
– use the body effectively
Intrapersonal
– understanding one's own interests, goals
Interpersonal
– understanding, interacting with others
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Criticisms of Gardner’s Theory
Underestimates general intelligence
Lacks measures
A talent is not an intelligence