1. Myers’ PSYCHOLOGY (5th Ed)
Chapter 11
Intelligence
James A. McCubbin, PhD
Clemson University
Worth Publishers

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

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

5. Origins of Intelligence
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 it is the average performance for a given age is assigned a score of 100

6. What is Intelligence? Intelligence
capacity for goal-directed and adaptive behavior
involves certain abilities
profit from experience
solve problems
reason effectively

7. What is Intelligence? IQ is a score on a test
it is not something you have
Is intelligence singular or multiple abilities?
Does it relate to speed of brain processing?

8. Intelligence Is intelligence culturally defined?
Are intelligence tests culture free?

9. Are There Multiple Intelligences?
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

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

11. 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
critical part of social intelligence

12. 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?

13. 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

14. Assessing Intelligence
Wechsler Adult Intelligence Scale (WAIS)
most widely used intelligence test
subtests
verbal
performance (nonverbal)
Wechsler Intelligence Scale for Children (WISC)
similar to WAIS, but for school children

15. 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

16. 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

17. The Normal Curve Number of scores 55 70 85 100 115 130 145
Ninety-five percent
of all people fall
within 30 points
of 100
Number of scores
Wechsler intelligence score
Sixty-eight percent
of people score
within 15 points
above or below 100

18. Getting Smarter?
Intelligence test performance has been rising

19. 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 the same individual
Validity
the extent to which a test measures or predicts what it is suppose to

20. 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

21. 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

22. 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.
Therefore, the predictive power of aptitude tests scores diminish as students move up the educational ladder.

23. The Dynamics of Intelligence
Mental Retardation
a condition of limited mental ability
indicated by intelligence scores below 70
produces difficulty in adapting to the demands of life
varies from mild to profound

24. The Dynamics of Intelligence
Down syndrome
retardation and associated physical disorders caused by an extra chromosome in genetic make-up

25. The Dynamics of Intelligence
Degrees of Mental Retardation
Level Typical Intelligence Scores Percentage of the Retarded Adaptation to Demands of Life
Mild % May learn academic skills up to
sixth-grade level. Adults may, with
assistance, achieve self-supporting
social and vocational skills.
Moderate May progress to second-grade level.
academically. Adults may contribute
to their own support by labor in
sheltered workshops.
Severe May learn to talk and perform simple
work tasks under close supervision
but are generally unable to profit from
vocational training.
Profound Below Require constant aid and supervision.

26. The Dynamics of Intelligence
Creativity
the ability to produce novel and valuable ideas
components of creativity
expertise
imaginative thinking skills
venturesome personality
intrinsic motivation
creative environment

27. Genetic Influences
Similarity of
intelligence
scores
(correlation)
Identical
twins
reared
together
apart
Fraternal
Siblings
Unrelated
individuals
The most genetically similar people have the most similar scores

28. Genetic Influences Heritability
Similarity of
intelligence
scores
(correlation)
Adopted
children
and
biological
parents
adoptive
Heritability
the proportion of variation among individuals that we can attribute to genes
variability depends on range of populations and environments studied

29. Variation within group Difference within group
Genetic Influences
Group differences and environmental impact
Variation within group
Difference within group
Poor soil
Fertile soil
Seeds

30. Genetic Influences The Mental Rotation Test of Spatial Abilities
Which two circles contains configuration of blocks
identical to the one in the circle at left?
Standard
Responses