Chapter 9 Intelligence: Measuring Mental Performance

1. Chapter 9 Intelligence: Measuring Mental Performance

2. WHAT IS INTELLIGENCE? • Psychometric Views of Intelligence • Intelligence is a trait (or set of traits) that allows some people to think and solve problems more effectively than others • Binet’s Singular Component Approach • Developed first intelligence test • Age graded items produced mental age • Intelligence is a general mental ability

3. WHAT IS INTELLIGENCE? • The Multicomponent View of Intelligence • Using factor analysis, not a single trait • Early multicomponent theories • Spearman; g = general mental; s = special ability • Thurstone; 7 primary mental abilities

4. Figure 9.1 Items similar but not identical to those appearing on intelligence tests for children.

5. WHAT IS INTELLIGENCE? • Later multicomponent theories • Guilford; 180 basic mental abilities • Structure-of-intellect model • Content, operations, products • Cattell & Horn • Fluid – solve novel, abstract problems • Crystallized – solve problems depending on acquired knowledge

6. Figure 9.2 An item from one of Guilford’s tests of social intelligence. The task is to read the characters’ expressions and to decide what the person marked by the arrow is most probably saying to the other person. You may wish to try this item yourself (the correct answer appears below). ADAPTED FROM GUILFORD, 1967.

7. WHAT IS INTELLIGENCE? • A recent hierarchical model • Carroll – three-stratum theory • g at top of pyramid • 8 broad abilities at second level • Narrow third-stratum abilities

8. WHAT IS INTELLIGENCE? • A Modern Information-Processing Viewpoint • Sternberg – triarchic theory of intelligence • The Contextual Component • Context, practical intelligence • The Experiential Component • Experience with test items • Automatization • The Componential Component • Information processing strategies

9. Figure 9.4 Sternberg’s triarchic theory of intelligence.

10. WHAT IS INTELLIGENCE? • Gardner’s Theory of Multiple Intelligences • 9 distinctive kinds of intelligence • Linked to a specific area of the brain • Follows a different developmental course • Each is independent of the others • This is a point of controversy; some intelligences are moderately correlated

11. Table 9.1 Gardner’s Multiple Intelligences

12. Table 9.1 Gardner’s Multiple Intelligences

13. HOW IS INTELLIGENCE MEASURED? • The Stanford-Binet Intelligence Scale • Original version • IQ of children 3 to 13 • Based on mental age / chronological age (MA/CA * 100) • Revised version – still in use • Normed on individuals 6 through adult • Deviation score compared with same aged others; 100 still average

14. HOW IS INTELLIGENCE MEASURED? • The Weschler Scales • Weschler Intelligence Scale for Children-IV (WISC-IV) • 6 to 16 years • Weschler Preschool and Primary Scale of Intelligence-III (WPPSI-III) • 3 to 8 years • Both contain verbal subtests, and nonverbal subtests

15. HOW IS INTELLIGENCE MEASURED? • Normally distributed around an IQ of 100 • Average score is set at 100 • Most scores between 85 and 115 • Very few beyond 130 • Few below 70, common definition of mental retardation

16. Figure 9.5 The approximate distribution of IQ scores people make on contemporary intelligence tests. These tests are constructed so that the average score made by examinees in each age group is equivalent to an IQ of 100. Note that more than two-thirds of all examinees score within 15 points of this average (that is, IQ’s of 85-115) and that 95 percent of the population scores within 30 of average (IQ’s of 70-130). ADAPTED FROM SATTLER, 1992.

17. Table 9.2 The Meaning of Different IQ Scores

18. HOW IS INTELLIGENCE MEASURED? • Group Tests of Mental Performance • More cost effective • Paper and pencil measures • Assess a group rapidly • SAT • ACT

19. HOW IS INTELLIGENCE MEASURED? • Newer Approaches to Intelligence Testing • The Kaufman Assessment Battery for Children (K-ABC) • Based on information-processing theory • Uses dynamic assessment • How well new material is learned with competent instruction • Based on Vygotsky and Sternberg

20. HOW IS INTELLIGENCE MEASURED? • Assessing Infant Intelligence • Bayley Scales of Infant Development • Motor scale • Mental scale – categorizing, searching for objects; following directions • Infant Behavioral Record • Motor and Mental combine to form DQ (developmental quotient) • Poor predictor of childhood IQ

21. Table 9.3 Description of Sub-Scales of the Bayley Scale of Infant Development

22. HOW IS INTELLIGENCE MEASURED? • New Evidence for Continuity in Intellectual Performance • Visual reaction time • Rate of habituation • Preference for novelty • All three moderately correlated with childhood IQ (average = .45)

23. HOW IS INTELLIGENCE MEASURED? • Stability of IQ in Childhood and Adolescence • Starting around age 4, relationship between early and later IQ’s • Becomes stronger with age • Large individual differences • 50% had average variations of over 20 points • Measures intellectual performance, not necessarily capacity in the future

24. Table 9.4 Correlations of IQ’s Measured during the Preschool Years and Middle Childhood, with IQ’s Measured at Ages 10 and 18. SOURCE: Adapted from Honzik, MacFarlane, & Allen, 1948.

25. HOW IS INTELLIGENCE MEASURED? • Stability, continued • IQ increases – children from stable, intellectually stimulating homes • IQ decreases – children living in poverty, especially prolonged • Cumulative-deficit hypothesis • Impoverished environments dampen intellectual growth, effects accumulate over time

26. Figure 9.6 Mental performance at age 6 years for early-adopted English children and Romanian orphans adopted at different ages. Notice that the longer the Romanian children had lived in the barren institutional environment, the lower their cognitive performance at age 6 – a finding that supports the cumulative-deficit hypothesis. ADAPTED FROM O’CONNER ET Al., 2000.

27. WHAT DO INTELLIGENCE TESTS PREDICT? • IQ as a Predictor of Scholastic Achievement • Good predictor (.50) • Do better in school • Stay in school longer • Go to college • Best predictor is actually past grades • Work habits, interests, motivation

28. WHAT DO INTELLIGENCE TESTS PREDICT? • IQ as a Predictor of Vocational Outcomes • IQ is related to occupational prestige/status • Due to link with education • Predicts job performance (.50) • Practical intelligence, also very important, not measured by IQ

29. WHAT DO INTELLIGENCE TESTS PREDICT? • IQ as a Predictor of Health, Adjustment, and Life Satisfaction • Terman’s longitudinal study • Most gifted children were happy, healthy, and led productive lives • Disruption of home environment – divorce, lack of support, worse outcomes

30. WHAT DO INTELLIGENCE TESTS PREDICT? • Health, Adjustment, and Satisfaction, cont. • Mental retardation sample • Organic – severe; institutionalized • Cultural-familial – (mild); low genetic potential and unstimulating environment • Less favorable outcomes than nonretarded, • Only 20% needed any assistance • Most married and were satisfied

31. Table 9.5 Midlife Occupations of Mentally Retarded, Nonretarded, and Gifted Males. SOURCE: Adapted from Ross et al., 1985.

32. FACTORS THAT INFLUENCE IQ SCORES • The Evidence for Heredity • Twin studies – resemblance increases as genetic similarity increases • Adoption studies – IQ more similar to biological than adoptive parents

33. FACTORS THAT INFLUENCE IQ SCORES • The Evidence for Environment • The Flynn Effect • Improving IQ scores since 1940 • Improvements in education, nutrition, and health care • Adoption Studies • Children leaving impoverished environments score very well on tests; higher IQ than predicted

34. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Home Environment and IQ • Assessing the Home Environment • HOME inventory – observer can determine how intellectually stimulating the home is (45 statements) • Asks parent about the daily routine • Observes child and parent interactions • Notes play materials

35. Table 9.6 Ten Environmental Risk Factors Associated with Low IQ and Mean IQs at Age 4 of Children Who Did or Did Not Experience Each Risk Factor. SOURCE: Data and descriptions compiled from Sameroff et al., 1993.

36. Table 9.7 Subscales and Sample Items for the HOME Inventory (Infant Version). SOURCE: Adapted from Caldwell & Bradley, 1984.

37. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Does the HOME Predict IQ? • Yes, regardless of social class or ethnicity; beyond parental IQ or genes • Which aspects matter most? • Creating a stimulating environment • Being involved in child’s learning • Explaining new concepts • Providing age appropriate challenges • Providing consistent encouragement

38. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Social-Class and Ethnic Differences in IQ • Children from lower- and working-class homes score 10-15 points lower on IQ • Children of African-American and Native-American ancestry score 12-15 points lower than European American classmates • Hispanic American between, Asian same as European American or higher • These are group-level differences

39. Figure 9.7 Approximate distributions of IQ scores from African American and white children reared by their biological parents. BASED ON BRODY, 1992; NEISSER, ET AL., 1996.

40. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Why Do Groups Differ in Intellectual Performance? • Cultural/Test Bias Hypothesis • Artifact of tests and testing procedures, favoring white, middle-class students

41. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Does “test bias” explain group differences • Same pattern with culture-fair tests (Raven Progressive Matrices) • IQ tests predict academic success equally well for all groups

42. Figure 9.8 An item similar to those appearing in the Raven Progressive Matrices Test.

43. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Motivational factors • Increasing comfort with testing situation and examiner can increase scores • Negative stereotypes • Reject behaviors such as excelling on tests – not relevant to them

44. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Genetic hypothesis • No conclusive evidence supporting genetics as causing between-group differences in intelligence exists! • Genetics is partly responsible for within-group differences

45. Figure 9.9 Why within-group differences do not necessarily imply anything about between-group differences. Here we see that the difference in the heights of the plants within each field reflects the genetic variation in the seeds that were planted there, whereas the difference in the average heights of the plants across the fields is attributable to an environmental factor: the soils in which they were grown. ADAPTED FROM GLEITMAN, 1991.

46. SOCIAL AND CULTURAL CORRELATES OF INTELLECTUAL PERFORMANCE • Environmental hypothesis • Poor people and minority group members score lower because • Impoverished environments • less conducive to intellectual development • Nutrition; Stress • Supported by research

47. IMPROVING COGNITIVE PERFORMANCE THROUGH COMPENSATORY EDUCATION • Goal – provide disadvantaged children the educational experiences that middle-class children were receiving (Head Start) • Long-term follow-ups • Higher IQ’s for 2-3 years, then decline • More likely to meet basic requirements • More likely to complete high school • More positive attitudes • Less likely to be delinquent

48. IMPROVING COGNITIVE PERFORMANCE THROUGH COMPENSATORY EDUCATION • The Importance of Parental Involvement • Parental involvement is essential • 2-generation interventions • The Importance of Intervening Early • Abecedarian Project • Began at 6-12 weeks old, continued until enrolled in school • Higher IQ, maintained through age 15

49. Figure 9.10 Average academic achievement scores at age 12 for Abecedarian preschool program participants and control children. ADAPTED FROM CAMPBELL & RAMEY, 1994.

50. IMPROVING COGNITIVE PERFORMANCE THROUGH COMPENSATORY EDUCATION • Chicago longitudinal study • High quality preschool program – good • Additional compensatory education – good • Although all are expensive, long term benefits are worth the investment