Intelligence & Psychological Testing

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Origins of Intelligence Testing Intelligence Test

a method of assessing an individual’s mental aptitudes and comparing them to those of others, using numerical scores

Origins of Intelligence Testing

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

Origins of Intelligence Testing

Stanford-Binet the widely used American

revision of Binet’s original intelligence test revised by Terman at Stanford

University

Origins of Intelligence Testing 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, the average performance for a given age is assigned a score of 100

What is Intelligence?

Intelligence ability to learn from experience,

solve problems, and use knowledge to adapt to new situations

What is Intelligence? 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

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

Assessing Intelligence

Wechsler Adult Intelligence Scale (WAIS) most widely used intelligence test subtests

verbal performance (nonverbal)

Assessing Intelligence: Sample Items from the WAIS

From Thorndike and Hagen, 1977

VERBAL

General Information Similarities Arithmetic ReasoningVocabularyComprehensionDigit Span

PERFORMANCE

Picture Completion Picture ArrangementBlock DesignObject AssemblyDigit-Symbol Substitution

Examples of IQ Test Items

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

The Normal Curve

Statistical Norms for IQ

Getting Smarter?

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

Validity the extent to which a test measures or predicts

what it is supposed to

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

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

Assessing Intelligence

As the range of data under consideration narrows, its predictive power diminishes

Greater correlationover broad rangeof body weights

10

9

8

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Little corre-lation withinrestricted

range

Football linemen’s

success

Body weight in pounds180 250 290

The Dynamics of Intelligence

Mental Retardation a condition of limited mental ability indicated by an intelligence score 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 one’s genetic makeup

The Dynamics of Intelligence

IQ Issues

• IQ scores are influenced by:– Socioeconomic status: middle class kids tend to do

better than lower class kids– Language status: children from the dominant

culture tend to do better– Age: IQ scores on timed tests tend to decline with

age– Heredity: IQ scores of identical twins raised apart

are quite similar

Genetic Influences

The most genetically similar people have the most similar scores

Genetic Influences Heritability

the proportion of variation among individuals that we can attribute to genes

variability depends on range of populations and environments studied

Reaction Range Genetically determined limits on IQ (other than

traits)

Genetic Influences

Environmental Influences The Schooling Effect

Group Differences Group differences and environmental impact

Variation within group

Variation within group

Difference within group

Poor soil Fertile soil

Seeds

Group Differences The Mental Rotation Test

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

Standard Responses

Group Differences

Stereotype Threat A self-confirming concern that one will

be evaluated based on a negative stereotype

Are There Multiple Intelligences? Savant Syndrome

condition in which a person otherwise limited in mental ability has an exceptional specific skill computation drawing

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

Intelligence and Creativity Creativity

the ability to produce novel and valuable ideas expertise imaginative thinking skills venturesome personality intrinsic motivation creative environment

Intelligence and Creativity Convergent Thinking

Narrows down a list of alternatives to “converge” on a single correct answer

Divergent Thinking Expands the range of alternatives by

generating many possible solutions.

Sternberg’s Triarchic Intelligence Theory

Giftedness and Achievement in Life

• Renzulli’s 3 ring concept:

Gardner’s Multiple Intelligences• People vary in their profile of 8 distinct forms of

intelligence: