Intelligence
What makes us smart?
Or not so smart?
Top 10 facts about IQ
1. School attendance
correlates with IQ
2. IQ is not
influenced by birth
order
3. IQ is related to
breast feeding
4. IQ varies by birth
date
5. IQ evens out with
age
6. Intelligence is plural
not singular
7. IQ is correlated
with head size
8. Intelligence scores
are predictive of
real-world outcomes
9. IQ is going up
10. IQ may be related to
the school cafeteria
menu!
Intelligence
• Intelligence – a mental
ability to learn from
experience, solve problems,
and use knowledge to adapt
to new situations.
• Socially constructed defined according to the
attributes that enable
success in a culture
– Example: problem solving
that demonstrates school
smarts or knowledge of
medicinal plants in the
amazon
According to this
definition, are both
Einstein and Ruth
intelligent?
Intelligence Tests
• Intelligence Test – a
method of assessing
mental aptitudes and
comparing them with
others
– Reification – converting
something abstract into
a material thing
• Example: claiming I’m
gifted because I have an
IQ of 145
Theories of Intelligence
• 5 Theories:
1.
2.
3.
4.
5.
g-intelligence (Spearman)
Thurstone’s primary mental abilities
Gardner’s Theory of Multiple Intelligence
Sternberg’s Three Intelligences
Emotional Intelligence
G factor (Spearman)
• General Intelligence (G) - a general
intelligence that underlies successful
performance on a wide variety of tasks.
– measured with a single numerical score
• Example - People who score above ave. on math
aptitude tests also score high on verbal aptitude
• The Stanford-Binet, WAIS, and WISC
 Factor analysis – statistical procedure
used to identify clusters of closely related
test items.
 Used to assess whether intelligence is a single
trait or a collection of several distinct abilities
(G intelligence uses factor analysis)
Thurstone’s Primary Mental
Abilities
• Thurstone challenged Spearman identified 7 clusters of mental
ability
• Word fluency, verbal comprehension,
spatial ability, perceptual speed,
numerical ability inductive reasoning
and memory
• Provides evidence for g intelligence
– Later found that those who excelled
in one of Thurstone's seven primary
mental abilities also demonstrated
high levels of competence in other
abilities
Howard Gardner and Multiple
Intelligences
• Gardner believed that
there are 8 different
types of intelligences.
1.
2.
3.
4.
5.
6.
7.
8.
Linguistic
Logical-mathematical
Spatial
Musical
Body-kinesthetic
Intrapersonal
Interpersonal
Naturalist
• Example
– Savant Syndrome – a person
who demonstrates an
exceptional specific mental
skill, but is otherwise limited
in intellectual capability
Triarchic Theory (Sternberg)
• Most commonly accepted theory today.
• Three types of intelligence
1. Analytical - ability to analyze and evaluate
ideas, solve problems and make decisions.
– Example: A student who solve a math problem
in record time
2. Creative - going beyond what is given to
generate novel and interesting ideas
– Example: Writing a short story when given
the title “The Octopus’s Sneakers”
3. Practical - ability that individuals use to
find the best fit between themselves and the
demands of the environment.
– Example: Business woman who can write
effectively, motivate people, delegate tasks
and promote her career
Think Pair Share
• Although Susan is a brilliant pianist and highly
acclaimed ballet dancer, her high school intelligence,
test scores were only average.
• Compare and Contrast the different theories of
intelligence as they relate to this statement
EQ – Emotional Quotient
• Social Intelligence – the ability to
comprehend social situations and
managing yourself successfully
• Emotional Intelligence – ability to
perceive, understand, manage and
use emotions
– 4 components
•
•
•
•
Perceive emotions
Understand emotions
Manage emotions
Use emotions
– Example: Low EQ - Someone who
frequently looses their temper (not
saying any names…)
– Criticism – stretches concept of
intelligence too far
Brain Size and Intelligence
Is there a link?
• Head Size - +.15
correlation between head
size and intelligence
scores (relative to body
size).
• Brain size - +.33
correlation
• Einstein’s Brian
– 15% larger in parietal lobe
• Math and spatial info
Brain Size and Complexity
• Higher performing brains:
– use less glucose
– have more synapses
– Increased neural
plasticity
– more gray matter (cell
body) in areas involved in
memory attention
language
BBrain Function
• Perceptual Speed – take in
perceptual images at
greater speed
– + 3-+5 correlation
• Neurological speed
– Fast reaction on simple
tasks (flash of light,
beeped tone)
– Retrieve info from
memory at high speeds
Assessing Intelligence
• Frances Galton – intellectual
superiority was inherited
– Measured muscular power, sensory
acuity, and body proportions
• Alfred Binet and Theodore Simon
– mental age - what a person of a
particular age should know.
Wanted to eliminate teacher bias and help
children, not label them.
– Example: 10 year old with an intellectual
performance of an 8 year old:
Mental Age = 8
Stanford-Binet (Terman)
• Used Binet’s
research to
construct the
modern day IQ test
called the StanfordBinet Test.
• IQ = Mental
Age/Chronological
Age X 100.
• A 8 year old has a
mental age of 10,
what is her IQ?
• A 12 year old has
the mental age of 9,
what is his IQ?
• A boy has the mental
age of 10 and an IQ
of 200, how old is
he?
Problems with the IQ Formula
If a 60 year old woman
does as well as an average 29 year old
then her IQ would be _______?
Ok, ok…an average 35 year old?
Then her IQ would be_________?
Still makes no sense!!!!!
• It does not really work well on adults, why?
• Terman assigned a chronological age of 20 for
all adults to fix this problem
The Normal Curve and
Stanford-Binet IQ Scores
Your score represents your performance relative to the
average performance (ave = 100) of others the same age
1 Standard deviation = ?
IQs less than 70 = intellectual disability. More than 130 = gifted
Table 6.2 Sample Items from the Stanford-Binet Intelligence
Test, Form L–M
The older the test taker is, the more the test requires in the way of verbal
comprehension and fluency.
Age Task
4 Fills in the missing word when asked, “Brother is a boy; sister is a .”
Answers correctly when asked, “Why do we have houses?”
9 Answers correctly when examiner says, “In an old graveyard in Spain they
have discovered a small skull which they believe to be that of Christopher
Columbus when he was about 10 years old.” What is foolish about that?
Examiner presents folded paper; child draws how it will look unfolded.
12 Completes “The streams are dry . . . there has been little rain.”
Tells what is foolish about statements such as “Bill Jones’s feet are so big that
he has to put his trousers on over his head.”
Adult Can describe the difference between misery and poverty, character and
reputation, laziness and idleness.
Explains how to measure 3 pints of water with a 5-pint and a 2-pint can.
Wechsler Tests
• More common
• Does not use the
formula but uses the
same scoring system.
• WAIS
• WISC
• WPPSI
Modern Tests of Mental Abilities
• Wechsler Adult Intelligence Scale (WAIS)
consists of 11 verbal and performance subtests
– Assesses Adult intelligence
– verbal comprehension, perceptual
organization, working memory, and processing
speed scores, as well as an overall
intelligence score
– Uses factor analysis
– A low or high score in one area can indicate a
cognitive weakness or strength
• i.e. low verbal comprehension = reading disability
• WISC – tests children’s intelligence
• Performance tests - Object assembly, picture
arrangement, and block design, digit span,
vocabulary
Wechler Adult Intelligence Scale
WISC
Aptitude v. Achievement Tests
Aptitude
• A test designed to
predict a person’s
future performance.
• Ability for a person
to learn a new skill.
• Example:
Achievement
• A test designed to
assess what a person
has learned
(knowledge and skills)
• Example:
Constructing Intelligence Tests
• Standardized - a person's test
performance can be compared with
that of a representative pretested
group (that has established a mean
for the test)
• How would you standardize the AP
Psych Exam?.
– Example: Give AP exam questions to a
representative sample of high school
and college psychology students in
order to be able to compare scores of
test-takers to this standardization
group
• Reliable: Test-Retest, Splithalves Methods.
• Validity: Content, Predictive or
Construct.
Normal Bell Curve
• Standardized tests form a normal
distribution or bell curve
• Few people deviate extremely from the ave.
– more than 2 standard deviations from the mean
– Examples:
• Height, weight and intelligence (WISC, WAIS,
Standford-Binet) scores all form a normal bell curve
• AP Exam scores also fall on a normal curve – few students
scoring 1 and 5, many students scoring 2, 3, 4
The Flynn Effect
• Performance on IQ scores has steadily increased
over generations
– Environmental factors NOT genetics
• Reduction in malnutrition
• Access to schooling
• Technological advances
– To avoid: need up to date standardization samples
Reliability
• Reliability - The extent which
a test yields consistent
results over time.
– Spilt halves - administering 2 halves of the
test items on a single test to two different
groups and comparing scores
• Ex. - giving even numbered questions to one group
and odd numbers to another and comparing results
– test–retest method – administering the test
more than once to a standardization group
– How would you insure the AP Psych Exam is
reliable using split halves? Using the testretest method?
• Ex – Giving the AP Exam to the same group twice
and comparing the results
Validity
Validity - the extent to which a test measures what it is supposed
to measure.
• Content Validity: does the test sample the behavior of interest
• Examples:
• AP test measures relevant psychology content by showing test items to
psychology professors
• Unit 11 exam has few questions about Intelligence – no content validity
• Predictive Validity: does the test predict future behavior.
– Aptitude tests have stronger validity in early school years, but weaken in
later school years. Why?
• How would test whether the AP Psych exam is valid?
• Examples:
• AP test scores reflect similar college grades by giving the test to both
high school and college students and comparing the scores to the college
students grades
• IF AP midterm exam was compared to scores on AP Exam and did not
have similar scores – no predictive validity
Think Pair Share
• Assume you are going to develop a new
test to predict job success for aspiring
novelists. Explain how you would
attempt to accomplish each of the
following in the new test:
– Content Validity
– Predictive Validity
– Standardization
– Reliability
Think Pair Share
• Assume you are going to develop a new test
to predict job success for aspiring pilots.
Define each of the following and explain how
you would attempt to accomplish each of the
following in the new test:
– Standardization
– Reliability
– Content Validity
– Predictive Validity
Intelligence Change Over Time
• Infant intelligence – indicator is
preference for looking at new picture
rather than old
• By age 4 - a child’s IQ can predict
adolescent IQ scores.
• By age 7 - intelligence scores begin to
stabilize and consistency increases
with age
• predictive validity of general aptitude
tests decrease as the educational
experience of students increases
– Ex. Correlation lowest between GRE and
graduate students
What is fluid intelligence?
• Our ability to learn new things fast and
abstractly (decreases with age)
What is crystallized intelligence?
• Old people intelligence - accumulated
knowledge and verbal skills (increases
with age
Extremes of Intelligence
• Akrit Jaswal
The Low Extreme
• Intellectual disability – both a
low test score and difficulty
adapting to independent living
–Down syndrome – people born with
an extra 21st chromosome
–Mainstreamed – regular and least
restrictive classrooms
Classifications of Intellectual Disability
Level
Mild
Approximate
Adaptation to Demands of Life
Intelligence
Scores
May learn academic skills up to sixth-grade
50-70
level. Adults may with assistance, achieve selfsupporting social and vocational skills
Moderate
35-50
May progress to second-grade level
academically. Adults may contribute to their
own support by laboring in sheltered workshops
Severe
20-35
May learn to talk and to perform simple tasks
under close supervision but are generally
unable to profit from vocational training
Profound
Below 25
Require constant aid and supervision
The High Extreme
• Terman’s study of gifted
– children were healthy, well adjusted,
academically successful
• Self-fulfilling prophecy
– can lead to self-fulfilling prophecy by
implicitly labeling some students as
“ungifted” and isolating them from an
enriched educational environment.
• Appropriate developmental
placement
– Tracking students
• widens the achievement gap between higherand lower-ability groups.
Twin and Adoption Studies
• Genes and Environmental influences
• Identical twin studies
– scores more similar for identical twins raised
apart than siblings or fraternal twins raised
together (genetic)
– Scores slightly dissimilar for identical twins
raised apart than together (environmental)
– Polygenetic Trait- different
chromosomal regions important to
intelligence have been identified
• Adoptive children studies
– Over time adoptive children’s IQ ‘s become
less positively correlated with adoptive
parents and more positively correlated with
biological parents
Heritability
• Heritability of Intelligence – the %
of variation in intelligence within a
group that is attributed to genetic
factions
– Example:
• Greatest in genetically dissimilar individuals who
have been raised in similar environments.
Correlation of Intelligence
Environmental Influences
• Early environmental influences
– Intellectual developmental delays
– Tutored human enrichment – trained
caregivers to imitate babies’ babbling
– Mozart effect – now discounted
finding that intelligence is boosted by
listening to classical music
• Schooling and intelligence
– Project Head Start
• Reduces likelihood that students
will repeat grades or require
special ed.
Gender Differences in Intelligence
Test Scores
• Girls
– Spelling
– Verbal ability
– Nonverbal ability
– Sensation – taste
touch, odor
– Emotion detecting
ability
– Math and spatial
aptitudes identical
• Boys
– Math problem
solving
– Higher SAT
– Go into math
fields
– Play chess
– Spatial abilities
Ethnic Differences in Intelligence
Test Scores
• Similarities
– Infant intelligence
• Black and white babies
are similar
• Differences
– Ave. intelligence scores
• Blacks – 85
• Whites – 100
– Math abilities
• Sweden/Iceland – no
gender gap
• Turkey/Korea – large
gender gap
– Asians outperform
North American’s on
math and aptitude tests
The Question of Bias
• Two meanings of bias
– Popular Sense – Culturally biased if lacks Content
Validity – has items that are unfamiliar to
minorities (i.e. biased against blacks)
– Scientific sense – biased if predictive validity is
not same for all groups
• Test-taker’s expectations
– Stereotype threat - Perform worse if feel
apprehensive because of stereotypes
• Feel you are evaluated based on a negative stereotype
• Example: women perform lower on math tests because
they feel apprehensive about test bias toward men.