(7th Ed)
James A. McCubbin, PhD
Clemson University
Worth Publishers

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

 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

 Stanford-Binet
 the widely used American revision of Binet’s original intelligence test
 revised by Terman at Stanford
University

 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


 ability to learn from experience, solve problems, and use knowledge to adapt to new situations

 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

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

 Social Intelligence
 the know-how involved in comprehending social situations and managing oneself successfully
 Emotional Intelligence
 ability to perceive, express, understand, and regulate emotions

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

 People who can perceive the stimulus very quickly tend to score somewhat higher on intelligence tests
Stimulus Mask
Question: Long side on left or right?

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
VERBAL
General Information
Similarities
Arithmetic Reasoning
Vocabulary
Comprehension
Digit Span
PERFORMANCE
Picture Completion
Picture Arrangement
Block Design
Object Assembly
Digit-Symbol Substitution
From Thorndike and Hagen, 1977

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

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
Football linemen’s
10
9 success
8
7
4
3
6
5
2
1
0
Greater correlation over broad range of body weights
Little correlation within restricted range
180 250 290
Body weight in pounds
 As the range of data under consideration narrows, its predictive power diminishes

 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

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

Genetic Influences

 The Schooling Effect

Group Differences
 Group differences and environmental impact
Variation within group
Variation within group
Seeds
Poor soil
Difference within group
Fertile soil

Group Differences
 The Mental Rotation Test
Which two of the other circles contain a configuration of blocks identical to the one in the circle at the left?
Standard Responses

Group Differences

 A self-confirming concern that one will be evaluated based on a negative stereotype