Chapter 9 Intelligence: Measuring Mental Performance

Chapter 9 Intelligence:

Measuring Mental Performance

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


– 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

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


• 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

• 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.


• A recent hierarchical model–Carroll – three-stratum theory

»g at top of pyramid»8 broad abilities at second level»Narrow third-stratum abilities


• 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

• Figure 9.4 Sternberg’s triarchic theory of 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

• Table 9.1 Gardner’s Multiple Intelligences

• Table 9.1 Gardner’s Multiple Intelligences

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


• 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


• 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

• 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.

• Table 9.2 The Meaning of Different IQ Scores


• Group Tests of Mental Performance– More cost effective– Paper and pencil measures– Assess a group rapidly

• SAT• ACT


• 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


• 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

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


– 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)


• 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

• 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.


• 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

• 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.

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


• 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


• 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


• 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

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

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

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

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

• 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.

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


– 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


• 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

• 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.


• Why Do Groups Differ in Intellectual Performance?– Cultural/Test Bias Hypothesis

• Artifact of tests and testing procedures, favoring white, middle-class students


• 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

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


• 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


– Genetic hypothesis• No conclusive evidence supporting

genetics as causing between-group differences in intelligence exists!

• Genetics is partly responsible for within-group differences

• 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.


– Environmental hypothesis• Poor people and minority group

members score lower because–Impoverished environments

»less conducive to intellectual development

»Nutrition; Stress»Supported by research

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


• 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

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


– Chicago longitudinal study• High quality preschool program – good• Additional compensatory education –

good– Although all are expensive, long term

benefits are worth the investment

CREATIVITY AND SPECIAL TALENTS

• Giftedness is defined as– High IQ (over 140)– Singular talents (music, art, etc)

• What is Creativity?– Ability to generate appropriate, novel ideas – The Psychometric Perspective

• Divergent thinking – many solutions–Modestly related to IQ–Home environment very important

• Figure 9.11 Are you creative? Indicate what you see in each of the three drawings. Below each drawing you will find examples of unique and common responses, drawn from a study of creativity in children. ADAPTED FROM WALLACH & KOGAN, 1965.


• The Multicomponent (Confluence) Perspective – convergence of factors– Sternberg & Lubart’s Investment Theory

• Intellectual resources–Find new problems–Evaluate ideas – good or bad–Sell others on the value of new ideas


– Sternberg & Lubart’s Theory, continued• Knowledge• Cognitive style – legislative – preference

for novel thinking• Personality – sensible risks,

perseverance, self-confidence• Motivation – for the work itself, not

rewards• A supportive environment


• A Test of Investment Theory– Test examining all factors except

environment showed all to be moderately to highly correlated with creativity

• Promoting Creativity in the Classroom– More divergent thinking– Support for new ideas– Tolerance for ambiguity

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Chapter 9 Intelligence: Measuring Mental Performance