Intelligence Chapter 9

What is intelligence? Where does it come from? How can it be measured?

What is Intelligence? Some definitions Binet defined intelligence as an individual’s capacity to: Find and maintain a definite direction or purpose Adjust strategy as necessary to achieve that purpose Evaluate or criticize that strategy so adjustments could be made Wechsler The aggregate or global capacity of an individual to act purposefully, think rationally, and deal effectively with the environment Kaplan and Saccuzzo General potential independent of prior learning

Spearman’s Theory of General Mental Ability Verbal Reasoning Quantitative Reasoning Logical Reasoning

Cattel & Horn’s Theory of Intelligence Crystallized Abilities Fluid Abilities Verbal Reasoning Quantitative Reasoning Abstract Visual Reasoning Vocabulary test Comprehension test Absurdities test Verbal relations test Quantitative test Number series test Equation building test Pattern analysis test Copying test Matrices test Paper folding & cutting test

Sternberg’s Triarchic Theory

Gardner’s Multiple Intelligences Logical-mathematical Linguistic Musical Spatial Bodily-kinesthetic Interpersonal Intrapersonal Naturalist

History of Intelligence Testing First intelligence tests were devised by Francis Galton In 1905, Binet developed test to measure child’s mental age Lewis Terman revised the Binet scale to produce the Stanford-Binet (introduced IQ) Weschler (1939) published improved measure for adults (introduced deviation IQ)

Intelligence Testing Today Intelligence tests contain diverse mix of questions assessing abstract reasoning Use modern deviation IQ scores normed for age Typically M=100 SD=15 IQ scores vary across testings but intelligence tests have high reliability Intelligence tests have demonstrated “limited” validity IQ tests are not widely used in non-Western cultures

Where Does Intelligence Come From? Nature (Hereditary) Twin studies Adopted children Heritability ratios Nurture (Environment) Adoption studies Environmental deprivation Environmental enrichment Generational increases Interaction Model Intelligence influence by both factors Heredity and environment also interact Reaction range model

Cultural Differences in IQ Scores Average IQ scores for large minorities is somewhat lower than the average for whites Jensen and others argue these differences result from heredity Kamin’s rebuttal Socioeconomic disadvantage Cultural test bias Mercer (1975) IQ argued tests measure ability and assimilation into mainstream culture Not much empirical evidence that this is a problem