Intelligence

1. Intelligence Meredyth Daneman PSY100

2. What is Intelligence? • abstract reasoning, problem solving, capacity to acquire knowledge • memory, mental speed, linguistic competence, mathematical competence, general knowledge, creativity • sensory acuity, goal-directedness, creativity • what intelligence tests measure

4. Overview • Nature of intelligence • Methods to measure intelligence • Theoretical approaches • Heredityand intelligence

5. Natureof Intelligence • Functional • Multi-faceted • Culturally Defined

6. Nature of Intelligence • Provisionally define intelligence as: the application of cognitive skills and knowledge to learn, solve problems, and obtain ends that are valued by an individual culture

7. IntelligenceTesting Intelligence tests are measures designed to assess an individual’s level of cognitive capabilities compared to other people in the population

8. IntelligenceTesting (Galton) SirFrancis Galton • believed building blocks of intelligence are simple sensory, perceptual, and motor abilities • found that these elementary tasks did not correlate with much of anything • pioneering statistician – correlation

9. IntelligenceTesting (Binet) Binet • believed that a true measure of intelligence is an individual’s performance on complex tasks of memory, reasoning, and comprehension • developed the concept of “mental age” or “mental level”

10. Intelligence Testing A child’s mental age (MA) indicates that he/she displays the mental abilities of a child of that chronological age (CA) • a child with a CA of 5 who can answer questions a typical 7-yr old answers, has a MA of 7 • a 5-yr old who can answer the questions expected for his/her age but no older, has a MA of 5

11. Intelligence Testing (Terman) Terman • revised the scales: Stanford-Binet • intelligence quotient (IQ), a score meant to quantify intellectual functioning to allow comparison among individuals

13. IQ = (MA/CA) X 100 8yr old performs at level of 12yr old • (12/8) X 100 = 150 • 12yr old performs at level of 8yr old • (8/12) X 100 = 66 • 12yr old performs at level of 12yr old • (12/12) X 100 = 100

14. Intelligence Testing (Wechsler) Wechsler • developed test that could be used for adults • WAIS (adults) • WPPSI (children) • verbal and performance subtests • frequency distribution of IQ scores

15. Wechsler Intelligence Scales: Verbal IQ

16. Wechsler Intelligence Scales: Performance IQ

17. Frequency Distribution of IQ Scores • Original IQ formula was useful for assessing children’s test performance, but not adults’ test performance • Wechsler remedied the problem by abandoning concept of MA and calculating IQ as an individual’s position relative to peers of the same age on a frequency distribution

18. The scores on an IQ test form an approximately bell-shaped curve. The curve shown here represents scores on the Wechsler IQ test, with a standard deviation of 15 (15 points above and below the mean, which is 100).

19. The Extremes of Intelligence • Mental retardation: • IQ less than 70 • about 2% of population • 75-90% are in mild to moderate range (IQ 50-70) • 10% in severe to profound range (IQ below 50)

20. The Extremes of Intelligence • Giftedness: • IQs exceeding 130

21. Validity & Reliability of IQ Tests • Validity: the ability to assess the construct it was designed to measure • Reliability: the ability to produce consistent results

22. IQ Testing: Criticism & Controversy • Lack of theoretical basis • Are IQ tests culturally biased? • Are IQ tests valid?

23. Approaches to Intelligence • psychometric approach • information-processing approach • multi-component approach

24. Psychometric Approach • The psychometric approach tries to identify groups of items in a test that correlate with one another in order to discover underlying skills or abilities • Factor analysis: a statistical procedure for finding patterns of correlations among measures in order to identify underlying factors or mental abilities

25. Identifying a Common Factor Sprint Weights Pullups Situps --------------------------------------------------------------------- Sprint --- .35 .45 .41 Weights --- --- .70 .52 Pullups --- --- --- .37 Situps --- --- --- --- ----------------------------------------------------------------------

26. Spearman’s Two-Factor Theory general factor or g-factor specific factors or s-factors

27. Cattell’s Theory • Fluid intelligence • speed and accuracy for abstract reasoning, especially for novel problems (drawing inferences, finding analogies, recognizing patterns) • Crystallized intelligence • accumulated knowledge and vocabulary

28. Thurstone: seven primary abilities • word fluency • comprehension • numerical computation • spatial skills • associative memory • reasoning • perceptual speed

29. Information-Processing Approach • tries to understand the processes that underlie intelligent behaviour; e.g., what is general intelligence or “g”? • various proposals: • working memory capacity • retrieving information from long-term memory • speed of processing (inspection time)

30. Theory of Multiple Intelligences (Gardner) • Seven intelligences • musical • bodily/kinesthetic • spatial • linguistic or verbal • logical/mathematical • intrapersonal • interpersonal

31. Gardner • Savants • one island of brilliance • Prodigies • extraordinary and generally early developing genius in one area, but normal abilities in others

32. Heredity and Intelligence Evidence for Hereditary Influences • twin studies • adoption studies

35. Heredity and Intelligence Evidence for Environmental Influences • adoption studies • environmental deprivation & enrichment • generational change (the Flynn effect)

36. Flynn Effect • IQ has been rising steadily over the industrialized world since 1930s • Has to be attributed to environmental factors • Hypotheses: • reductions in severe malnutrition • advances in technology (TV, computers, video games) • improved schools, smaller families, better educated and informed parents

37. Heredity vs. Environment individual differences vs. group differences

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