myers’ psychology c11:1 intelligence chapter 11...

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C11:1

Myers’ PSYCHOLOGY

Chapter 11

Intelligence

C11:2Intelligence

• Intelligence testing

– One of several approaches to human cognition in psychology

– Several already discussed

• Piaget: theory of cognitive development

• Experimental psychology: memory, language, thinking

– Central part of various applied domains

• Clinical practice, Education, Industrial-Organizational, psychologies specific to various occupations (e.g., Military, Protective Services, …)

– Extremely controversial area

• Group differences and their implications

C11:3Outline

• What is intelligence?– Single vs. Multiple

Abilities

– Emotional Intelligence

– Intelligence and Creativity

– Neuroscience

• Assessment

– Origins of Intelligence Testing

– Modern tests

– Test Construction

• Dynamics

– Stability or Change

– Extremes

• Genetic and Environmental Influences

– Genetic

– Environmental

– Group Differences

– Question of Bias

C11:4What is intelligence?

• Defining Intelligence

–Intelligence Quotient (discussed later) is score on a test of intelligence, not something tangible that people have

• Problem of Reification

–Some common themes in definitions of intelligence (+1 +2)

• Capacity or Ability of some sort

• Adaptive

• Involves reasoning, thinking, conceptualizing, …

C11:5Early Definitions

• Binet (1916)

– Capacity to judge, reason, and comprehend well

• Terman (1916)

– Capacity to form concepts and grasp their significance

• Pintner (1921)

– Ability to adapt well to new situations in life

• Thorndike (1921)

– Good responses from point of view of truth or fact

• Thurstone (1921)

– Capacity to inhibit instinctive response, imagine other response, and realize modified response

• Spearman (1923)

– General ability to see relations and correlates

• Wechsler (1939)

– Global capacity to act purposefully, think rationally, and deal effectively with environment

C11:6Contemporary Definitions

• Piaget (1972)

– Superior forms of organization or equilibrium of cognitive structuring used to adapt to physical and social environment

• Sternberg (1985)

– Mental capacity to automatize information processing and to emit contextually appropriate behavior in response to novelty

• Gardner (1986)

– Ability to solve problems or fashion products valued within some setting

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C11:7

One General Ability or Several Specific Abilities?

• A major debate concerns “structure of intelligence”

– Basic question is whether “intelligence” is single ability or multiple abilities

– Factor Analysis: statistical procedure that identifies number of dimensions that underlie scores on multiple specific tasks (+1)

– Although issue is generally settled, still debated

– Why no resolution?

• Results depend somewhat on what tasks and what people are tested (see Gardner’s view later)

• Also different variations of Factor Analysis, some biased toward single factor and some toward multiple factors

C11:8Hypothetical Factor Analysis Results for 6 Tests

• Single Factor underlying T1 to T6

Correlation Matrix

T1 T2 T3 T4 T5 T6

T1 .6 .6 .6 .6 .6

T2 .6 .6 .6 .6

T3 .6 .6 .6

T4 .6 .6

T5 .6

T6

Factor structureg

F1 F2

T4 T5 T6T1 T2 T3

g

T1 T2 T3 T4 T5 T6

• Several Factors underlying T1 to T6

Correlation Matrix

T1 T2 T3 T4 T5 T6

T1 .6 .6 .3 .3 .3

T2 .6 .3 .3 .3

T3 .3 .3 .3

T4 .6 .6

T5 .6

T6

Factor structure

C11:9

One Ability or Multiple

• Single Ability - General Intelligence (g)

– Factor that Spearman and others believed underlies specific mental abilities

– Measured by every task on intelligence test

– Reflected in positive r between different tasks involving intelligence

• Multiple General Abilities

– Thurstone ( 1938 ) -Primary Mental Abilities

• Number ability

• Verbal ability

• Word fluency

• Memory

• Reasoning

• Spatial ability

• Perception

– Some scholars noted modest rs between abilities

C11:10

One Ability or Multiple

• Gardner’s Multiple Intelligences

– Based his model on different criteria than other researchers, not factor analysis of tests

– Speculations based on

• Brain damage: impression that specific competencies lost when

different regions of brain damaged

• Savant Syndrome: Condition in which person otherwise limited in mental ability has some amazing specific skill

– Computation, Counting, Drawing, Remembering, …

– VERY broad definition of intelligence that included 8 types of “intelligence” (+1 +2)

– Now speculates about 9th form: existential intelligence is ability to think about question of life, death and existence

C11:11

One Ability or Multiple: GardnerC11:12

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C11:13One Ability or Multiple

• Sternberg’s Triarchic Model of Practical Intelligence

– Analytical Intelligence: assessed by intelligence tests

– Creative Intelligence: adapt to novel situations, generating novel ideas

– Practical Intelligence: required for everyday tasks (e.g. street smarts)

• Tacit knowledge that shares following qualities

• Procedural rather than factual, which means it is knowledge about how to do something rather than knowledge about something

• Usually learned without help of others or explicit instruction

• Knowledge about things personally important to learner

C11:14One Ability or Multiple: Comparison

C11:15

Emotional Intelligence

• Proposed by Salovey and Mayer and defined as

– Ability to perceive, express, understand, and regulate emotions (+1)

– Seen as critical part of social intelligence (Cantor & Kihlstrom): comprehending social situations and managing successfully

• Again controversial

– Even Gardner (who proposed inter- and intra-personal intelligence) wonders whether Emotional Intelligence extends concept too far

– Empirical questions about usefulness

C11:16

Emotional Intelligence

Use emotions to adapt or be creative

Express emotions in different situations

Predict emotions, how they change and blend

Recognize emotions in faces, music and stories

Description

Manage emotion

Use emotion

Understand emotion

Perceive emotion

Component

C11:17

Intelligence and Creativity

• Creativity

– Produce ideas that are:

• BOTH novel

• AND valuable

– Divergent vs. Convergent Thinking

– Components

• Expertise

• Imaginative

• Venturesome

• Intrinsic motivation

• Creative environment

C11:18Intelligence and Neuroscience

• Relating Intelligence to Brain– People who can perform task above quickly tend to

score higher on intelligence tests

– Gray matter more concentrated in certain areas (above)

– Brain size correlates about .40 with intelligence

– Brain Imaging• Frontal lobes active during cognitive tasks

• High IQ people’s brains LESS active during tasks

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C11:19Outline

• What is intelligence?

– Single vs. Multiple Abilities



– Neuroscience

• Assessment– Origins of Intelligence

Testing

– Modern tests


• Dynamics


– Extremes


– Genetic

– Environmental



C11:20

Origins -Overview

• Galton

• Binet

• Terman and Stanford-Binet

• World War I

• Wechsler Tests

C11:21Origins

• Francis Galton

– Charles Darwin’s cousin

– Interested in heredity and genius (tends to run in families), but regression to mean (average)

– Invented correlation coefficient

– Introduced idea intelligence could be quantified

– Founded eugenics movement

– Measured basic psychological processes (e.g., reaction time, basic perceptual tasks)

• Not very successful at predicting intelligence (unlike more recent efforts just discussed)

C11:22History

• Alfred Binet (and Theodore Simon)– Started modern intelligence testing in

1890s

– Invited to predict children's future progress in Paris school system

• Identify children who need special assistance

• Distinguish various levels of retardation

– Rejected Galton approach of simple tasks

• Developed more complex, standardized tasks

• Defining words, Repeating digits, Reasoning

– Able to discriminate children across entire range of ability, not just lower end

C11:23History• Lewis Terman– Stanford University psychologist

– Developed Stanford-Binetintelligence test

– Established age-level norms• "Intelligence Quotient”: IQ = 100 x

MA/CA

• Formula derived by German psychologist William Stern

• Chronological age became standard to compare behavioral accomplishments of individuals

– Complex test• Many different tasks, depending on

age

• Required much training and time to administer

C11:24History

• World War I Tests

– Suitability of recruits for military positions

• Job, Rank

– Army Alpha and Beta tests: group tests

• Alpha: verbal, group Stanford-Binet

• Beta: nonverbal, for illiterates, non-English speakers

• Administered to 1,726,966 men

• Scores translated into letter grade (A to D-)– %age As: Recruits (7.4), Corporals (16.1), Sergeants (24.0), 2nd

Lieutenants (59.4), Majors (64.4)

– Increased success during training and service

• Saved much time, expense, and lives, according to advocates

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C11:25History

• Wechsler tests

– Developed tests most widely used today

– Tasks based on work of predecessors

– Individual tests, simpler than Stanford-Binet

– Overall IQ divided into components and sub-tasks

• Verbal

• Performance

C11:26• Modern Tests: Types of Cognitive Tests

– Achievement Tests: Assess what person has learned in specific domains (Reading, Math, …)

– Aptitude Tests: Designed to predict future performance in diverse domains

• Aptitude is capacity to learn

• Intelligence tests are aptitude tests: IQ and SAT

C11:27Modern Tests

• Wechsler Tests: Different versions for broad age ranges– WAIS: Wechsler Adult Intelligence Scale

– WISC: Wechsler Intelligence Scale for Children

– WPPSI: Wechsler Pre-school & Primary Scale of Intelligence

• Wechsler Adult Intelligence Scale (WAIS)– Most widely used intelligence test

– 10-12 tasks, classified into two groups

– Verbal

– Performance (nonverbal)

– V-IQ, P-IQ, and Full-Scale IQ, as well as specific sub-scale scores

C11:28

Verbal Sub-Tests of WAIS

C11:29

Performance Sub-tests of WAIS

C11:30Principles of Test Construction

• Standardization

– Administer test to many people, representative of population for which test is intended

– Define meaningful scores by comparison with performance of pre-tested “standardization group”

– Deviation IQs calculated based on normal distribution (+1)

• Classic CA/MA no longer used

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C11:31Assessing Intelligence

• Normal Curve (+1)

– Distribution of scores

• Values along horizontal axis from low to high scores

• Proportion of people obtaining scores on vertical axis

– Most scores fall near average, and fewer and fewer scores lie near extremes

– Symmetrical bell-shaped curve

• Describes distribution of many physical and psychological attributes

– Precise statements possible about scores

• e.g., 84% below Mean + 1 Standard Deviation (IQ=115)

C11:32The Normal Curve

C11:33Flynn Effect

• IQ Tests re-standardized every so many years because of Flynn Effect (below)

C11:34Principles of Test Construction

• Reliability

– Degree to which test yields consistent results

– Assessed by consistency of scores (r) on:

• Two halves of test

• Alternate forms of test

• Retesting same individual

– Results

• Typical IQ measures produce consistent scores

• IQs very consistent (stable) after 7 years of age (see later slide on Stability)


• Validity

– Degree to which test measures or predicts what it should

– Complex question, hence many “types” of validity (i.e., ways to validate tests)

• Content Validity

– Extent to which test samples behavior of interest

• Driving test that samples driving tasks


• Criterion Validity

– r with behavior (such as college grades) that test (such as SAT) designed to predict

• Predictive Validity

– Success with which test predicts behavior it is designed to predict

– Assessed by correlation between test scores and measures of criterion behavior

– Also called criterion-related validity

• Some complications: e.g., Corrections for restricted range (+1) and non-reliability increase observed correlations

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• Validity and Restriction of Range

– As range of data narrows, predictive power weakens

– Predictive power of aptitude tests diminishes as students move up educational ladder

Greater r overbroad range

of IQs

10

9

8

7

6

5

4

3

2

1

0

Lower r withinrestricted

range

AcademicSuccess

On 10-pointScale

Intelligence Quotient (IQ)

80 100 120

C11:38Intelligence & School Performance

• WISC-R and standardized achievement tests

– Verbal .61, Performance .41

• WAIS and high school rank


• WAIS and college grade point average


– Lower because of Restriction of Range

C11:39Intelligence & Education Level

IQs

Years of Schooling Range Mean

16+ College Graduate 87-148 115.2

13-15 Some College 76-139 107.3

12 High School Graduate 63-141 100.0

9-11 Some High School 59-146 96.4

8 Elementary Graduate 65-125 90.8

0-7 Some Elementary 53-139 82.5

C11:40

Intelligence & Occupation Group

IQs

Occupation Range Mean

Professional & Technical 81-148 112.4

Manager, Clerical, Sales 73-137 103.6

Skilled Workers 72-131 100.7

Semiskilled Workers 56-135 92.3

Unskilled Workers 53-126 87.1

Not in Labour Force 55-146

C11:41

Intelligence & Job Performance

• Success in Training

– 828 studies in Military, .62

– Ghiselli: .65, higher for more complex jobs

• Job Performance

– Ghiselli: varies with complexity

• Manager (.53), Clerk (.54), Salesperson (.61)

• Crafts and Trades (mid .40s)

• Low complexity (high .20s and .30s)

C11:42Outline





– Neuroscience

• Assessment


– Modern tests


• Dynamics– Stability or Change

– Extremes


– Genetic

– Environmental



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C11:43Stability or Change

• Infant tests (0 to 2 years)

– Bayley Scales of Infant Development• Based on sensorimotor alertness

• Inconsistent, do not consistently predict later IQ

– New tests

• Speed of response to visual stimulus

• Rate of habituation

• Preference for novelty

• Average r=.45 with child IQ

– After 7 years or so IQs more stable (+1 +2)

C11:44Dynamics

• Stability of IQ

– Age & Correlation with IQ at age 18

Age r

4 .42

6 .61

8 .70

10 .76

12 .76

• Honzik, Macfarlane and Allen, 1948

C11:45r = .66 over 7 Decades

C11:46Extremes of Intelligence

• Two extreme groups

– Lows: bottom 2%, at or below IQ of 70

– Highs: top 2%, at or above IQ of 130


• Low Extreme = Mental Retardation

– Limited mental ability (degrees … +1)

– Indicated by intelligence scores below 70

– Difficulty adapting to demands of life

– Varies from mild to profound

• Causes

– Down Syndrome: Retardation and associated physical disorders caused by extra chromosome in genetic make-up

– Fetal Alcohol Syndrome: now one of most common causes of mental retardation


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• High Extreme

– Gifted

• Terman

– 1,500 school children with IQs > 135

– Followed for 70 years beginning in 1921

– Well-adjusted, Successful

• Confirmed by later studies

– e.g., gifted children much more likely to study for doctorate at later age (50x average)

• Controversy over special school “tracks” for gifted

C11:50Outline





– Neuroscience

• Assessment


– Modern tests


• Dynamics


– Extremes

• Genetic and Environmental Influences– Genetic

– Environmental



C11:51Causes of Variation in Intelligence

• Individuals and Groups differ on IQ tests (and on correlated measures, such as school achievement)

• Much controversy about cause of differences

– Heredity: Role of Genetic make-up and Evolution of intelligence (+1 +2)

– Environment: Various aspects of physical and social environment, including biological conditions

– Difficult issues to resolve scientifically, and complicated by excessive politicalization

C11:52

C11:53 C11:54Genetic Influences

• Heritability

– Proportion of variation among individuals attributed to genes

– Variability depends on range of populations and environments studied

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C11:55Genetic Influences

• More genetically similar people are, more similar their IQ scores (Environment effect discussed later)

C11:56Genetic Influences

C11:57Environmental Influences

• Studies of people varying in genetic relatedness and environmental similarity (+1)

• Environmental Deprivation– e.g., Romanian orphanages

• Early Intervention Studies– Head Start: Success of high quality programs

– McVicker Hunt: Children in impoverished Iranian orphanage improved by training care-givers to play vocal games with infants

– Success of Early Adoption (+2)

• Schooling effect (+3)

• Flynn Effect (+4)

C11:58Environmental Influences

• Environment effect: Reared Together more similar than Reared Apart (genetic effect discussed earlier)

C11:59

Scarr’sCross-Race Adoption Results

C11:60Environmental InfluenceSchooling Effect: Kids in higher grade have higher

IQs than similar age kids in lower grade

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C11:61

Environmental Influence - Flynn EffectC11:62Gene By Environment Interaction

• Interaction: Effect of one variable depends on Level of another variable

– Effect of Genes depends on Level of Environment

OR

– Effect of Environment depends on Level of Genes

• Weak and Strong interactions

– Range of Reaction (+1)

– Strong Interaction (+2)

C11:63

Range of Reaction

C11:64

Strong Interaction: Cooper & Zubeck

C11:65Group Differences

• Evidence that average IQs of people differ across ethnic, cultural, and social groups– Blacks in USA about 1 SD below average

– Asians somewhat higher than Whites on Quantitative

– Females somewhat higher than Males on Verbal

– Males somewhat higher on Spatial / Quantitative

– Higher SES tend to score higher on IQ tests

• Note that Variability also important for extremes (F11.12)

• Much controversy over explanation (Genes or Environment) and relevance of prior research

C11:66

2. Girls verbally fluent and have large vocabularies

3. Girls better at locating objects

4. Girls more sensitive to touch, taste, and color

5. Boys outnumber girls in counts of underachievement

6. Boys outperform girls at math problem solving, but under perform at math

computation

7. Women detect emotions more easily than men do

1. Girls better spellers

Gender Differences

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• Gender and Mathematics Performance

– Small differences in average can produce large differences at extremes (Math “geniuses” in picture)

– Variability also important for effect

– Controversial: e.g., President Summers at Harvard


• The Mental Rotation Test of Spatial Abilities

Which two circles contain configuration of blocksidentical to one in circle at left?

Standard Responses

C11:69Group Differences: Genes & Environment

• Group differences and environmental impact

C11:70Are IQ tests biased?

• Not in obvious ways sometimes claimed in popular press and even courts

– Black children not worse on items critics believe unfair (e.g., what to do when someone hits you)

– Tests predict school performance equally well

(from Sattler, 1992, p. 567)

Achievement Area

Reading Arithmetic

Ethnic Group # Mdn r # Mdn r

Anglo-American 14 .52 12 .54

Black-American 17 .60 11 .58

Hispanic-American 7 .51 7 .53

C11:71Stereotype Threat (Steele)

– Verbal items solved adjusted by SAT score

Race

Not Primed Primed

White 7 9

Black 8 4

– Gender and Mathematics Performance

Score corrected for guessing

Instructed on Gender Difference?

No Yes

Men 19% 28%

Women 18% 6%

C11:72Conclusion

• Much evidence for usefulness and validity of standardized intelligence tests

• But, also cases of abuse of these instruments

– Eugenics movement

– Arguments against Head Start and similar programs designed to help disadvantaged children

• As in many areas,

– Important to appreciate complexity of area: e.g., contribution of both genes and environment, and their interaction

– Application of knowledge must be done intelligently

myers’ psychology c11:1 intelligence chapter 11...

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