1. Intelligence Chapter 10 Myers’ PSYCHOLOGY James A. McCubbin, PhD
Clemson University
Worth Publishers

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

3. 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

4. Origins of Intelligence Testing
Stanford-Binet
the widely used American revision of Binet’s original intelligence test
revised by Terman at Stanford University

5. 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

6. What is Intelligence? Intelligence
ability to learn from experience, solve problems, and use knowledge to adapt to new situations

7. What is Intelligence? Factor Analysis General Intelligence (g)
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

8. Are There Multiple Intelligences?
Savant Syndrome
condition in which a person otherwise limited in mental ability has an exceptional specific skill
computation
drawing

9. 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

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

11. Brain Function and Intelligence
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?

12. 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

13. Assessing Intelligence
Wechsler Adult Intelligence Scale (WAIS)
most widely used intelligence test
subtests
verbal
performance (nonverbal)

14. Assessing Intelligence: Sample Items from the WAIS
From Thorndike and Hagen, 1977
VERBAL
General Information
Similarities
Arithmetic Reasoning
Vocabulary
Comprehension
Digit Span
PERFORMANCE
Picture Completion
Picture Arrangement
Block Design
Object Assembly
Digit-Symbol Substitution

15. 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

16. The Normal Curve

17. Getting Smarter?

18. 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

19. 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

20. 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

21. Assessing Intelligence
Greater correlation
over broad range
of body weights 10 9 8 7 6 5 4 3 2 1
Little corre-
lation within
restricted
range
Football linemen’s
success
Body weight in pounds
As the range of data under consideration narrows, its predictive power diminishes

22. 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

23. The Dynamics of Intelligence

24. Genetic Influences
The most genetically similar people have the most similar scores

25. Genetic Influences Heritability
the proportion of variation among individuals that we can attribute to genes
variability depends on range of populations and environments studied

26. Genetic Influences

27. Environmental Influences
The Schooling Effect

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

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

30. Group Differences Stereotype Threat
A self-confirming concern that one will be evaluated based on a negative stereotype