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 up10.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

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• 5Theories:

1. g-intelligence (Spearman) 2. Thurstone’s primary mental abilities3. Gardner’s Theory of Multiple Intelligence4. Sternberg’s Three Intelligences5. 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. Linguistic2. Logical-mathematical3. Spatial4. Musical5. Body-kinesthetic6. Intrapersonal7. Interpersonal8. 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 intelligence1.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

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: Someone who frequently looses their temper (not saying any names…)

– Criticism – stretches concept of intelligence too far

Think Pair Share

• Although Susan is a brilliant pianist and highly acclaimed ballet dancer, her high school intelligence test scores were only average. What does Susan's experience suggest regarding the nature of intelligence

Brain Size and IntelligenceIs 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 Stanford-Binet Test.

• IQ logical 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

• It does not really work well on adults, why?• Terman assigned a mental age of 20 for all

adults to fix this problem

then her IQ would be _______?

Ok, ok…an average 35 year old? Then her IQ would be_________?

If a 60 year old woman

does as well as an average 29 year old

Still makes no sense!!!!!

The Normal Curve and Stanford-Binet IQ Scores

IQs less than 70 = mental disability. More than 130 = gifted

Your score represents your performance relative to the average performance (ave = 100) of others the same age1 Standard deviation = ?

Table 6.2 Sample Items from the Stanford-Binet Intelligence Test, Form L–MThe older the test taker is, the more the test requires in the way of verbal comprehension and fluency.

Age Task4 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 TestsAptitude• 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, Split-halves 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 test-retest method?

• Ex – Giving the AP Exam to the same group twice and comparing the results

ValidityValidity - 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• 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

• Depends on the type of intelligence, crystallized or fluid.

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–Mental retardation–Down syndrome – people born with an extra 21st chromosome

–Mainstreamed – regular and least restrictive classrooms

Classifications of Intellectual Disability

Level Approximate

Intelligence Scores

Adaptation to Demands of Life

Mild 50-70 May learn academic skills up to sixth-grade level. Adults may with assistance, achieve self-supporting 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 higher- and 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 more 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 (50%)– 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.

• Ian and Nolan are identical twins who were adopted into different families shortly after birth. Use what you know about the stability of intelligence over time and the relative contributions of genetic and environmental factors to predict how similar Ian and Nolan's IQ scores will be at age 5 and age at 25. 

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 – biased if test performance is influenced by cultural experiences (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.