Last Week!Last Week!

Exam Saturday, December 17th, 12 noonDo NOT be late!!!65 Multiple choice5 of 7 definitions4 of 7 short answers2 of 3 longer answers3 hours longShort answers and essay CUMULATIVE

Intelligence and Testing: HistoryIntelligence and Testing: History

Brass instruments in 1800s– Wundt (1832 – 1920)– Galton (1822 – 1911)– Cattell (1860 – 1944)– Wissler (in 1901)

Testing: HistoryTesting: History

Advent of the Modern testing– Attitudes towards mentally ill and mentally

delayed were changing

Alfred Binet– Developed a scale for the Paris government in

1905

Binet’s scaleBinet’s scale

Had 4 characteristics:1. Measured a child’s general mental abilities,

and was aimed at classification, not assessment

2. Brief and practical

3. Practical judgment was measured rather than low-level abilities

4. Items arranged by level of difficulty

Examples of itemsExamples of items

1. Follows object with moving eyes3. Grasps item that is seen7. Points to familiar-named object (point to the cup)10. Compares two lines of markedly unequal length18. Reproduces from memory 2 designs shown for

10 seconds22. Compares 5 blocks to put them in order of weight26. Puts 3 nouns or 3 verbs in a sentence30. Defines abstract words by designating the

difference between them (e.g boredom and weariness)

Binet continuedBinet continued1908

– Calculation of mental level– Standardization

1911– 5 tests for each age level

1916– Terman’s influence: people started comparing

ration of mental age and chronological age: Mental age / chronological age = 100

IQ testing comes to AmericaIQ testing comes to America

Goddard:– American recruited by Vineland training school

to identify and classify “feebleminded” children

MA and diagnosis of Vineland MA and diagnosis of Vineland Residents tested with a translation of Residents tested with a translation of

the Simon-Binetthe Simon-Binet

Binet-Simon Mental Age

Diagnosis Number of Residents

I & II Idiot 73

III to IV Imbecile 205

VIII to XII Feebleminded 100

The Simon-Binet comes to AmericaThe Simon-Binet comes to America

Goddard imports testNormal sample of 1 547 normal children

yielded 3% of these children were feebleminded

His work on Ellis Island in 1910

Group TestingGroup Testing

Army needed a fast way to assess potential recruits

Yerkes’ Army Alpha & Army BetaAlpha had 8 verbally loaded subtests

Following Oral Directions: mark a cross in the 1st and also the 3rd circle:

Arithmetical Reasoning: How many men are 5 men and 10 men?

Synonym-Antonym pairs: Are these the same or opposites? accumulate - dissipate

Number Series Completion: Complete the series:

3 6 8 16 18 36… …

Analogies: Complete the analogy:

Tears-sorrow:: laughter joy smile girls grin

Group TestingGroup Testing

0 was most common score on Army alpha

Yerkes (1921) calculation of Army Yerkes (1921) calculation of Army Alpha DataAlpha Data

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100

150

200

250

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350

400

Score

0 10 20 30 40

Number of people with score

Test 4 Alpha

Group testing con’dGroup testing con’d

Army Beta designed for illiterates or for people whose first language was not English

Consisted of mazes, mentally counting blocks, number-symbol completions

Army beta testsArmy beta testsTest 3

O O O O…

X X X X…

OOXOOXOOX…

XXXOXOXXXOXO...

Test 4

62 62

59 56

327 327

249 249

1536 1536

3745 3745

45010 45001

62019 62019

Test 7

Very bizarre testing conditionsBrigham’s misuse of the data

Group testing con’dGroup testing con’d

Brigham’s (1923) use of Yerkes’ dataBrigham’s (1923) use of Yerkes’ data

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Nordic Alpine, Mediterranean African

History of Intelligence Testing, History of Intelligence Testing, summarysummary

Attempts to measure intelligence have been laden with problems, and the use of the measures is questionable

How you develop a test will depend on how you define and see intelligence

Some Views of IntelligenceSome Views of Intelligence

Spearman: a general ability which involves mainly the eduction of relations and correlates

Binet & Simon: the ability to judge well, to understand well, and to reason well

Piaget: A generic term to indicate superior forms of organization and equilibrium of cognitive structuring used for adaptation to the physical and social environment

Definitions of IntelligenceDefinitions of Intelligence

Problems with operational definitions Layperson’s and expert’s definitions are

similar Experts agree on 2 part definition:

1. The capacity to learn from experience

2. The capacity to learn from one’s environment

Approaches to IntelligenceApproaches to Intelligence

Spearman’s g– Finds high correlations between various subtests– One general factor (g) and several specific factors (s1,

s2, s3, etc…)– Invented factor analysis– Performance due to g and a specific ability on the

subfactors– g was energy or power in the whole cortex, and the s

factor was a substrate

CattellCattell

Distinguished between fluid and crystallized intelligence

Fluid = nonverbal, culture-reduced, learning and problem-solving

Crystallized = Language and world knowledge

PiagetPiaget

Cognitive stages are progression in intelligence, and process of adaptation is reflection of intelligence

Performance on conservation tasks was his indication of intelligence, had to match age and stage

Gardner’s Multiple IntelligencesGardner’s Multiple Intelligences

8 criteria for an intelligence:– Potential isolation by brain damage– Existence of idiot savants– Identifiable core operations– Distinctive developmental history– Evolutionary plausibility– Support from experimental psychology– Support from psychometric findings– Susceptibility to symbol encoding

Gardner’s Multiple IntelligencesGardner’s Multiple Intelligences

9 intelligences:1. Linguistic Intelligences2. Musical intelligences3. Logical-Mathematical intelligences4. Spatial intelligences5. Bodily Kinesthetic intelligences6. Interpersonal intelligences7. Intrapersonal intelligences8. Naturalist intelligences9. Spirituality/existential intelligences

Information Processing approachesInformation Processing approaches

Like in other cognitive domains, look at how knowledge base, speed of processing, working memory, and metacognition affect performance on tests of intelligence

ScalesScalesStanford-Binet

– Heavily verbalWechsler Scales

– Differs from above in terms of non-verbal itemsKaufman Assessment Battery for children

– Heavily non-verbal and believed to be culture-fair, and E. has more flexibility when administering

Bayley scales– Measures infant intelligence

IQ: Nature or Nurture?IQ: Nature or Nurture?

Heritability indexEvidence for Nature

– Honzik

Evidence for Nurture– Skeels– Teratogens

Fetal alcohol syndrome and Fetal alcohol effect

Differences between groups?Differences between groups?

Problems occur when we take previous arguments and apply them to individual groups

Making IQ inherited is making it a characteristic that is necessarily destined and immutable

Started with Cyril Burt, whose work guided policy in the ‘60s and ‘70s

Differences between groups?Differences between groups?

Cyril Burt faked his dataHis defenders were large proponents of

inherent racial differences in IQ, e.g. JensenThe Bell Curve by Herrnstein and Murray

The Bell CurveThe Bell Curve

Relies on faulty statistical analysisRelies on work of problematic work of J.

Phillipe Rushton

Racial differences in IQ, con’dRacial differences in IQ, con’d

Genetic hypothesis is also untenable for 2 very strong reasons:– Problems with generalizing within-group

differences to between group differences– A crucial prediction does not hold up: degree of

ancestry has no effect on IQ (Scarr, 1977)

Intelligence and cognitive Intelligence and cognitive developmentdevelopment

Transactional model of development

Environment Genotype Phenotype

Phenotype Genotype Environment

There is continuous interaction of child’s constitution and the environment over time

Example of SES and intelligenceExample of SES and intelligence

Children from high SES homes have higher IQ than those from low SES homes

BUT…SES does not work aloneRelated to home environment, peer group,

academic expectations etc…so could be any of these things or all of them

Back to Heritability Back to Heritability

How much of a trait is there because of genes?

Heritability is not independent of environment (debate is extent of contribution of each)

Behavioural GeneticsBehavioural Genetics

May not be g that is inherited, but rather aspects of information-processing – Memory capacity– Neural transmission– Durability of memory traces

These develop over time and may be more susceptible to environmental effects

Behavioural Genetics con’dBehavioural Genetics con’d

Degree of relatedness can predict heritability of IQ

Genetics accounts for about 50% of variance, more so in MZt

Varies from population to population and from culture to culture

More correlated over time

Behavioural GeneticsBehavioural Genetics

Large effects of environment also found: why?

Nature side looks at correlations…

Correlation of IQ as a function of Correlation of IQ as a function of Genetic SimilarityGenetic Similarity

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Relatedness

Parent/ AdoptiveOffspring

Siblings Apart

Siblings Together

Dizygotic twinstogether

Monozygotic twinsapart

Monozygotic twinstogether

Effects of environmentEffects of environment

Nurture side looks at means Scarr & Weinberg:

– Disadvantaged children adopted into advantaged home show big jump in IQ, similar to their adoptive parents

– BUT IQ still predicted by birth mother’s education level…

HOW??? – They maintain rank order, but IQ changes

Effects of early experienceEffects of early experience

Deprivation in the 1st 2 months of life can have a detrimental effect on intellectual and social development– Institution and War children

Home environment can also affect intellectual development– Use of HOME scale

HOME scaleHOME scale

6 subscales to measure type of early environment child is in

1. Emotional and verbal responsivity of Mother2. Avoidance of restriction and punishment3. Organization of physical and temporal env.4. Provision of appropriate play materials5. Maternal Involvement with the child6. Opportunities for variety in daily stimulation

HOME scaleHOME scale

Correlation between score on HOME scale and Stanford-Binet score at age 2

Predicts academic performance at age 11BUT maintenance depends on child’s future

environment (risk factors)

Interaction of risk factorsInteraction of risk factors

Caughy (1996) looked at biological risk factors (Low birth weight, hospitalization) and environmental risk factors (low income, low maternal education)

Impact of biological risk factors can be mediated by good home, low environmental risk factors

More environmental effects…More environmental effects…

Maternal behaviours predicts child’s intellectual development

Legerstee revisited

Effect of ChildEffect of Child

Piaget’s views of child as activeChild’s behaviour will affect how they are

treatedChildren have personalities, and can control

their environment

Stability of Intellectual FunctioningStability of Intellectual Functioning

Can be changed for the better– Skeels’ institution study– Preschool program can help– Head Start

Can also change for the worse– Children can lose early benefits if environment

is drastically changed

Back to infants’ DQBack to infants’ DQ

Looking at specific processing skills is more fruitful than looking at overall functioning

Strong correlations found between infants’ “preference for novelty” and later IQ

Suggests an underlying process that child uses over early years that predicts later learning

And that, my friends, is cognitive development…

Remember exam is Cumulative!Remember exam is Cumulative!