What is
Chapter 8
Intelligence and Individual Differences
SO, what did you get on your SATs?
Jane said she got a 1350…that means
she’s really smart, right?
Does it?
Module Objectives:
What is intelligence?
How do we measure intelligence?
Who are the children whose intelligence sets them
apart from their peers?
Think on Your Own…
How do YOU define Intelligence?
Is it the ability to use reason and logic?
Is it the ability to write and speak clearly?
Is it limited to one’s performance in school?
Is it behavior in social situations?
How about knowing when you’re wrong?
Not that simple, right?
There are many psychological theories about
intelligence that we will examine in this
How do we know intelligence
even exists?
Psychometricians specialize in measuring
psychological characteristics for intelligence and
personality. By using patterns of test scores, they
have found evidence for general intelligence as well
as for specific abilities
What is Intelligence?
Intelligence is an inferred process that
humans use to explain the different degrees
of adaptive success in people’s behavior
‐ The mental abilities that enable one to adapt to,
shape, or select one’s environment
‐ The ability to judge, comprehend, and reason
‐ The ability to understand and deal with people,
objects, and symbols
‐ The ability to act purposefully, think rationally, and
deal effectively with the environment
Spearman’s Psychometric Approach Intelligence as a Single Trait
Psychometric Approach
‐ The measurement (metric) of individual
differences in behaviors and abilities
George Spearman reported findings supporting the
idea that performance on any test of mental ability
was based on a single general ability factor that he
termed “g”
Spearman also believed that performance on any
test of mental ability required the use of a specific
ability factor that he termed “s”
s Mechanical
Conflicting theories have led many
psychometric theorists to propose
hierarchical theories of intelligence
that include both general and
specific components
Cattell’s View of Intelligence Intelligence as a Few Basic Abilities
Fluid Intelligence
‐ The ability to think on the spot and solve novel
‐ The ability to perceive relationships
‐ The ability to gain new types of knowledge
Crystallized Intelligence
‐ Factual knowledge about the world
‐ The skills already learned and practiced
‐ Examples
‐ Arithmetic facts
‐ Knowledge of the meaning of words
‐ State capitals
Intelligence Tests and
Basic Abilities
Fluid intelligence on tests is measured by:
‐ The ability to assemble novel puzzles
‐ The ability to determine the next entry in a series of
‐ The ability to identify which one of four objects is related
to the others
Children who do well on one test of fluid intelligence
usually do well on other tests of fluid intelligence
‐ They may no necessarily perform well on tests of
crystallized intelligence
Three-Stratum Theory
of Intelligence - John Carroll
Carroll’s hierarchal theory is
essentially a compromise between
general and distinct abilities view of
Some critics still find it unsatisfactory
because it ignored the research and theory on
cognitive development
Broader Theory of Intelligence
Howard Gardener proposed a theory of
multiple intelligences, in which he identified 9
distinct types of intelligence.
The first three intelligences are included in
psychometric theories of intelligence:
‐ Linguistic intelligence
‐ Logical-Mathematical Intelligence
‐ Spatial Intelligence
What Do These Intelligences Examine?
Linguistics - sensitivity to the meanings and sounds
of words, mastery of syntax, appreciation of the
ways language can be used
Logical-Mathematical - Understanding of objects
and symbols and of actions that be performed on
them and of the relations between these actions,
ability to identify problems and seek explanations
Spatial - capacity to perceive the visual world
accurately, to perform transformations upon
perceptions and to re-create aspects of visual
experience in the absence of physical stimuli
Gardener’s Theory of Multiple
Gardener’s remaining 6 distinct intelligences
are unique to Gardner’s theory:
Existential intelligence
What are these Intelligences?
Musical - Sensitivity to individual tones and phrases of music, an
understanding of ways to combine tones and phrases into larger musical
rhythms and structures, awareness of emotional aspects of music
Bodily-Kinesthetic - Use of one’s body in highly skilled ways for expressive
or goal-directed purposes, capacity to handle objects skillfully
Interpersonal - Ability to notice and make distinctions among the moods,
temperaments, motivations, and intentions of other people and potentially
to act on this knowledge
Intrapersonal - access to one’s own feelings, ability to draw on one’s
emotions to guide and understand one’s behavior, recognition of personal
strengths and weaknesses
Naturalistic -- sensitivity and understanding of plants, animals, and other
aspects of nature
Existential - sensitivity to issues related to the meaning of life, death, and
other aspects of the human condition
The question arises… should we use the
word intelligence to describe all valuable
skills like doing calculus, speaking 6
different languages, being able to make the
throw from home to second?
If we do… then Gardner is correct… people do
have many unrelated kinds of intelligence. Now
we have changed the definition and meaning of
Gardener’s theory has prompted
researchers to begin examining
other nontraditional aspects of
The best known is emotional intelligence
How is Intelligence
The first Intelligence test was
created by Binet and Simon using
simple tasks to distinguish children
who would do well in school from
those who wouldn’t
Binet and Simon used Mental age to
distinguish “bright” from “dull”
What is IQ?
Lewis Terman revised Simon and Binet’s test
and published a version known as the
Stanford-Binet Test in 1916.
Performance was described as an intelligence
quotient (IQ) which was imply the ratio of
mental age to chronological age multiplied by
‐ IQ=MA/CA x 100
Stanford-Binet IQ Test
This test measures things that are necessary for school
‐ Understanding and using language, memory, the ability to
follow instructions, and computational skills
Binet’s test is a set of age-graded items
‐ Binet assumed that children’s abilities increase with age
‐ These items measure the person’s “mental level” or
“mental age”
Adaptive Testing
‐ Determine the age level of the most advanced items that a
child could consistently answer correctly
‐ Children whose mental age equal their actual or
chronological age were considered to be of “regular”
Sample Stanford-Binet Test Items
Name objects from memory; complete analogies (fire is hot; ice is ______); identify
objects of similar shape; Answer simple questions (Why do we have schools?)
Define simple words; Explain differences (between a fish and a horse); identify
missing parts of a picture; count out objects
Answer questions about a simple story; explain similarities and differences among
objects; tell how to handle certain situations (finding a stray puppy)
Define more difficult words; Give explanations (about why people should be quiet in
a library); List as many words as possible; repeat 6-digit numbers
Identify more difficult verbal and picture absurdities; repeat 5-digit numbers in
reverse order; define abstract words (sorrow); fill in a missing word in a sentence
Supply several missing words for incomplete sentences; Repeat 6-digit numbers in
reverse order; Create a sentence using several unrelated words; Describe similarities
between concepts
Measuring Intelligence
At any age, children who are average will
have an IQ of 100 because their mental age
equals their chronological age.
‐ Roughly two-thirds of children will have an IQ
score between 85 and 115
‐ Approximately 95% will have scores between 70
and 130
Intelligence Quotient (IQ)
This summary is used to indicate a child’s
intelligence relative to others of the same age
IQ tests measure an individual’s probable
performance in school and similar settings
An IQ test measures performance… but an IQ
test does not explain performance
A Five-Minute IQ Test
Water lilies double in area every 24 hours. At the beginning of the
summer, there is one water lily on a lake. It takes 60 days for the
lake to become covered with water lilies. On what day is the lake
A farmer has 17 sheep. All but 9 break through a hole in the fence
and wander away. How many are left?
If you have black socks and brown socks in your drawer, mixed in a
ratio of 4 to 5. How many socks will you have to take out in order
to have a pair of the same color?
With a 7-minute hourglass, and an 11-minute hourglass, how can
you time the boiling of an egg for 15-minutes?
Washington is to one as Lincoln is to:
Five --or-- Ten --or-- Fifteen --or-- Fifty
How did you do?
On day 59. Remember, it doubles every day.
Nine sheep. It is just a matter of careful reading.
Three socks. The ratio information is irrelevant.
Allow both glasses to drain simultaneously. As soon as
the 7-minute glass empties, flip it over (7 minutes have
expired). Then, flip it over again after the 11-minute glass
empties (11 minutes have expired). Fifteen minutes will
have passed when the 7-minute glass empties.
The answer is five. The task here is to realize that the
relation is no the sequence of their presidency but which
denomination of bill upon which each face appears.
Another test used frequently are the
Wechsler Intelligence Scale
Wechsler Intelligence Scale for ChildrenThird Edition (WISC-III)
‐ Used with children 6 to 16
Wechsler Adult Intelligence Scale-Third
Edition (WAIS-III)
‐ Used with people 17 and older
Provides a profile of someone’s strengths and
Each test is made of 12 parts
‐ Each part begins with the simplest questions and
progresses to increasingly difficult ones
‐ Performance Scale (6 parts)
‐ Spatial and perceptual abilities
‐ Measures fluid intelligence
‐ Verbal Scale (6 parts)
‐ General knowledge of the world and skill in using
‐ Measures crystallized intelligence
Verbal IQ is based on:
‐ Information
‐ Measures a child's range of factual information
‐ Example: What day of the year is Independence Day?
‐ Similarities
‐ Measures a child's ability to categorize
‐ Example: In what way are wool and cotton alike?
‐ Arithmetic
‐ Measures the ability to solve computational math problems
‐ Example: If I buy 6 cents worth of candy and give the clerk
25 cents, I would get _________ back in change?
‐ Vocabulary
‐ Measures the ability to define words
‐ Example: What does “telephone” mean?
‐ Comprehension
‐ Measures the ability to answer common sense questions
‐ Example: Why do people buy fire insurance?
‐ Digit Span
‐ Measures short-term auditory memory
Performance IQ is based on:
‐ Coding
‐ Copying marks from a code; visual rote learning
‐ Picture Completion
‐ Telling what's missing in various pictures
‐ Example: Children are shown a picture, such as a car with no
wheels, and are asked: What part of the picture is missing?
‐ Picture Arrangement
‐ Arranging pictures to tell a story
‐ Block Design
‐ Arranging multi-colored blocks to match printed design
‐ Example: Using the four blocks, make one just like this
‐ Object Assembly
‐ Putting puzzles together - measures nonverbal fluid reasoning
‐ Example: If these pieces are put together correctly, they will make
something. Go ahead and put them together as quickly as you can.
The Stanford-Binet and the WISCIII cannot be used to assess infant
The Bayley Scales of Infant Development are
often used for infant assessment
Do Intelligence tests work?
To answer this question we must
examine Reliability and Validity
How Stable is IQ?
Research suggests that intelligence is relatively
stable from early childhood on
IQ scores tend to be fairly stable
‐ IQ test at 4 and a second at 17 - 13 points up or down
‐ IQ test at 8 and a second at 17 - 9 points up or down
‐ IQ test at 12 and a second at 12 - 7 points up or down
The closer together in time that IQ tests are given…
the more consistent (stable) the scores.
Do tests scores really measure
This is a question of validity. Does the test
measure what it claims to measure?
Most test developers argue that their tests are
valid measures of intelligence by showing that
test scores are related to children’s grades in
Factors that Influence
Factors Influencing Intelligence
The Child’s Influence
‐ Genetics
‐ Genotype–Environment Interaction
‐ Gender
The Immediate Environment’s Influence
‐ Family Environment
‐ School Environment
The Society’s Influence
‐ Poverty
‐ Race/Ethnicity
Boys and girls tend to be equivalent in most aspects of
‐ The average IQ scores of boys and girls is virtually
‐ The extremes (both low and high ends) are overrepresented by boys
Girls as a group:
‐ Tend to be stronger in verbal fluency, in writing, in
perceptual speed (starting as early as the toddler years)
Boys as a group:
‐ Tend to be stronger in visual-spatial processing, in
science, and in mathematical problem solving (starting as
early as age 3)
Attending school makes children smarter
‐ Children from families of low SES and those from
families of high SES make comparable gains in school
achievement during the school year
What about during summer break?
‐ Children from families of low SES have a drop in
achievement scores
‐ Children from families of high SES have achievement
scores that stay constant or rise slightly
The more years children spend in poverty, the lower
their IQs tend to be
‐ Children from lower- and working-class homes average
10-15 points below their middle-class age mates on IQ
In many countries, children from wealthier homes
score better on IQ test than children from poorer
‐ The greater the gap in wealth in a country the greater the
difference in IQ scores
Poverty Continued…
Chronic inadequate diet can disrupt brain
‐ Chronic or short-term inadequate diet at any
point in life can impair immediate intellectual
Reduced access to health service, poor
parenting, and insufficient stimulation and
emotional support can impair intellectual
Race and Ethnicity
The average IQ score of Euro-American
children is 10-15 points higher than that of
African-American children
The average IQ score of Latino and
American-Indian children fall somewhere in
between those of Euro-American and
African-American children
The average IQ score of Asian-American
children tend to be higher than any other
group in the US
Race and Ethnicity Continued…
American-Indian children:
‐ Better on the performance part than the verbal part of an
IQ test
Latino children:
‐ Better on the performance part than the verbal part of an
IQ test
Asian-American children:
‐ Better on the performance part than the verbal part of an
IQ test
African-American children:
‐ Better on the verbal part than the performance part of an
IQ test
Overall - differences in IQ scores of children from different
racial and ethnic groups describes children’s performance
ONLY in the environments in which the children live
Culture-Fair Intelligence Tests
Raven’s Progressive Matrices
‐ A “culture-fair” or culture-reduced test that would make
minimal use of language and not ask for any specific facts
‐ These matrices progress from easy to difficult items -measures abstract reasoning
Even on culture-fair tests, Euro-American and
African-American children still differ
‐ One reason - culture can influence a child’s familiarity
with the entire testing situation

What is Intelligence?