Chapter 9: Intelligence and Its Measurement
•What is intelligence?
•Definitions
•Intervening Variables
•Factor Analytic Approaches
•Alternative Approaches
•Binet Scales
•Wechsler Scales
•Definitions
•Galton
•Binet
•Wechsler
•Piaget
•Nature of Intelligence
•Innate vs. Environment
•Heritability index
•Twin studies have demonstrated good evidence of genetic influence
•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
•Stability of Intelligence
•Is there a decline in IQ across age cohorts?
–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
•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
•Interacting Variables
•Personality factors
•Measurement Process
•Gender roles
•Socioeconomic Status (SES)
•Culture
•Cumulative Experiences
•Conventional Intelligence Tests
•Measure general level of intellectual performance
•Functions
•Preliminary screening
•Academic
•Identification of mentally retarded
•Clinical
•Limitations of IQ Scores
•Validity is a tests ability to assess the construct it is trying to assess
•IQ is what IQ tests measure
•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
•Factor Analytic Approaches
•Based on statistical analysis of test scores (factor analyses)
•Finding common dimensions of intelligence
•Two factor Theory (g-s)
•General factor “g”
–electrochemical mental energy, abstract reasoning (facility of thinking)
•Specific factors "s"
•Spearman later accepted there were “group factors”
•Objective is to obtain tests high in "g"
•Examples
•Binet-Simon scale (high in verbal)
•Raven's Progressive Matrices
•Catell's Culture Fair Intelligence Test
•Multi-Factor Approaches
•Advanced by Thorndike (1921)
–social
–concrete
–abstract
•Current theory accepts that there are a number of broad group factors
•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
– verbal-educational and practical-mechanical
•3 - Minor group factors
–verbal and numerical, mechanical, spatial subfactors
•4 - Specific factors
•Structure of Intellect Model (Guilford, 1967)
•Three dimensions
1. Operations
2. Contents
3. Products
•Raymond B. Catell (1971) factor analytic model
•fluid intelligence
–non-verbal, culture free
–mazes
•crystallized intelligence
–exposure and education
•Alternative Approaches
•Information Processing (Luria, 1966)
•Two basic styles (separate but complementary)
–simultaneous (parallel)
–successive (sequential) information is individually processed in sequential fashion
•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
•Criticisms of Gardner’s Theory
•Underestimates general intelligence
•Lacks measures
•A talent is not an intelligence