Myers’ PSYCHOLOGY (6th Ed)

1. Myers’ PSYCHOLOGY (6th Ed) Chapter 11 Intelligence James A. McCubbin, PhD Clemson University Worth Publishers

2. Origins of Intelligence • Intelligence Test • a method of assessing an individual’s mental aptitudes and comparing them to those of others, using numerical scores

3. Origins of Intelligence • Mental Age • a measure of intelligence test performance devised by Binet • chronological age that most typically corresponds to a given level of performance • child who does as well as the average 8-year-old is said to have a mental age of 8

4. Origins of Intelligence • Stanford-Binet • the widely used American revision of Binet’s original intelligence test • revised by Terman at Stanford University

5. Origins of Intelligence • Intelligence Quotient (IQ) • defined originally the ratio of mental age (ma) to chronological age (ca) multiplied by 100 • IQ = ma/ca x 100) • on contemporary tests it is the average performance for a given age is assigned a score of 100

6. What is Intelligence? • Intelligence • capacity for goal-directed and adaptive behavior • involves certain abilities • profit from experience • solve problems • reason effectively

7. What is Intelligence? • IQ is a score on a test • it is not something you have • Is intelligence singular or multiple abilities? • Does it relate to speed of brain processing?

8. Intelligence • Is intelligence culturally defined? • Are intelligence tests culture free?

9. Are There Multiple Intelligences? • Factor Analysis • statistical procedure that identifies clusters of related items (called factors) on a test • used to identify different dimensions of performance that underlie one’s total score • General Intelligence(g) • factor that Spearman and others believed underlies specific mental abilities • measured by every task on an intelligence test

10. Are There Multiple Intelligences? • Savant Syndrome • condition in which a person otherwise limited in mental ability has an amazing specific skill • computation • drawing

11. Are There Multiple Intelligences? • Social Intelligence • the know-how involved in comprehending social situations and managing oneself successfully • Emotional Intelligence • ability to perceive, express, understand, and regulate emotions • critical part of social intelligence

12. Mask Stimulus Question: Long side on left or right? Brain Function and Intelligence • People who can perceive the stimulus very quickly tend to score somewhat higher on intelligence tests

13. Assessing Intelligence • Aptitude Test • a test designed to predict a person’s future performance • aptitude is the capacity to learn • Achievement Test • a test designed to assess what a person has learned

14. Assessing Intelligence • Wechsler Adult Intelligence Scale (WAIS) • most widely used intelligence test • subtests • verbal • performance (nonverbal)

15. VERBAL PERFORMANCE Picture Completion Picture Arrangement Block Design Object Assembly Digit-Symbol Substitution General Information Similarities Arithmetic Reasoning Vocabulary Comprehension Digit Span From Thorndike and Hagen, 1977 Assessing Intelligence- Sample Items from the WAIS

16. Assessing Intelligence • Standardization • defining meaningful scores by comparison with the performance of a pretested “standardization group” • Normal Curve • the symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes • most scores fall near the average, and fewer and fewer scores lie near the extremes

17. Number of scores Sixty-eight percent of people score within 15 points above or below 100 Ninety-five percent of all people fall within 30 points of 100 55 70 85 100 115 130 145 Wechsler intelligence score The Normal Curve

18. Getting Smarter? • Intelligence test performance has been rising

19. Assessing Intelligence • Reliability • the extent to which a test yields consistent results • assessed by consistency of scores on: • two halves of the test • alternate forms of the test • retesting the same individual • Validity • the extent to which a test measures or predicts what it is suppose to

20. Assessing Intelligence • Content Validity • the extent to which a test samples the behavior that is of interest • driving test that samples driving tasks • Criterion • behavior (such as college grades) that a test (such as the SAT) is designed to predict • the measure used in defining whether the test has predictive validity

21. Assessing Intelligence • Predictive Validity • success with which a test predicts the behavior it is designed to predict • assessed by computing the correlation between test scores and the criterion behavior • also called criterion-related validity

22. 10 9 8 7 6 5 4 3 2 1 0 Greater correlation over broad range of body weights Football linemen’s success Little corre- lation within restricted range 180 250 290 Body weight in pounds Assessing Intelligence • As the range of data under consideration narrows, its predictive power diminishes. • Therefore, the predictive power of aptitude tests scores diminish as students move up the educational ladder.

23. The Dynamics of Intelligence • Mental Retardation • a condition of limited mental ability • indicated by intelligence scores below 70 • produces difficulty in adapting to the demands of life • varies from mild to profound • Down Syndrome • retardation and associated physical disorders caused by an extra chromosome in genetic make-up

24. Degrees of Mental Retardation Level Typical Intelligence Scores Percentage of the Retarded Adaptation to Demands of Life Mild 50-70 85% May learn academic skills up to sixth-grade level. Adults may, with assistance, achieve self-supporting social and vocational skills. Moderate 35-49 10 May progress to second-grade level. academically. Adults may contribute to their own support by labor in sheltered workshops. Severe 20-34 3-4 May learn to talk and perform simple work tasks under close supervision but are generally unable to profit from vocational training. The Dynamics of Intelligence Profound Below 20 1-2 Require constant aid and supervision.

25. The Dynamics of Intelligence • Creativity • the ability to produce novel and valuable ideas • components of creativity • expertise • imaginative thinking skills • venturesome personality • intrinsic motivation • creative environment

26. Similarity of intelligence scores (correlation) Siblings reared together Unrelated individuals reared together Identical twins reared together Identical twins reared apart Fraternal twins reared together Genetic Influences • The most genetically similar people have the most similar scores

27. Genetic Influences • Heritability • the proportion of variation among individuals that we can attribute to genes • variability depends on range of populations and environments studied

28. 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 Child-parent correlation in verbal ability scores Children and their birth parents Adopted children and their birth parents Adopted children and their adoptive parents 3 years 16 years Genetic Influences

29. 118 115 112 109 106 103 100 97 IQ gains relative to grade 4 baseline Grade 6 Grade 5 Grade 4 110 115 120 125 130 135 140 145 150 Age in months Genetic Influences • The Schooling Effect

30. Variation within group Variation within group Seeds Poor soil Fertile soil Difference within group Genetic Influences • Group differences and environmental impact

31. Standard Responses Genetic Influences • The Mental Rotation Test of Spatial Abilities Which two circles contains configuration of blocks identical to the one in the circle at left?