Unit 11: Testing and
Individual Differences
What is Intelligence?

Intelligence  mental quality
consisting of the ability to learn from
experience, solve problems, and use
knowledge to adapt to new situations.

Meanings can vary from culture to
culture.

How might the North American
culture asses or define intelligence
as compared to other cultures around
the world? DISCUSS

HINT: Use the picture of the
traditional folk healer as a starting
off point.

Is intelligence one aptitude or many? Based on cognitive speed or
neurologically measurable? Easiest way to think about it, is that intelligence
is a ‘concept’ not a ‘thing’. Therefore it is interpretable on many levels.

So, when intelligence is measured by IQ (Intelligence Quotient), as if it is a
fixed trait (like height) a reasoning error occurs, called reification – viewing
an abstract, immaterial concept, as if it were a concrete thing.

Using an intelligence test ( a method of assessing an individual's mental
aptitudes and comparing them with those of others, using numerical scores),
simply places a person along a scale as compared with others scores.

Street smarts vs. Book smarts.
Is Intelligence One General Ability or
Several Specific Abilities?

Can you think of someone who is great at science but has a hard time with math? Someone
who may be amazing at math, but can’t hold their own in a literary discussion. Are these
people still intelligent? Can you rate them only on a single scale?

General Intelligence  a general intelligence factor that, according to Spearman and others,
underlies specific mental abilities and is therefore measured by every task on an intelligence
test. By Charles Spearman,

Usually just called ‘G’…. Not like the original G… just G. What at title to have ! It’s like
Madonna!

Spearman developed factor analysis  a general intelligence factor that, according to
Spearman and others, underlies specific mental abilities and is therefore measured by every
task on an intelligence test.

L.L. Thurstone tried to counter the G theory. When Spearman tested people, he noticed that if
they scored high in one category, they tended to score high in other categories as well.
Thurstone did a series of tests to counter this. His results? Same as Spearman. Therefore it is
commonly accepted that general intelligence is correct.
g

How to organize or theorize general intelligence? Think of an athlete. If you
are good at long distance running, it may not mean your are good at
powerlifting. However, if you are in overall, good athletic shape, you will
probably be good at a larger variety of sports than a person who is out of
shape.
Theories of Multiple Intelligences

Since the G classification, psychologists have been trying see how
intelligences may interact.

Think of savant syndrome ( a condition in which a person otherwise limited in
mental ability has an exceptional specific skill, such as in computation or
drawing), where the individual typically scores low on an intelligence test but
have an island of brilliance somewhere else.) There is more than one way to be
‘smart’.
Savant Syndrome
Is Intelligence One General Ability or Several Specific Abilities?
Theories of Multiple Intelligences
 Gardner’s

Eight Intelligences
Linguistic
 Logical-mathematical
 Musical
 Spatial
 Bodily-kinesthetic
 Intrapersonal
 Interpersonal
 Naturalist
Is Intelligence One General Ability or Several Specific Abilities?
Theories of Multiple Intelligences
Is Intelligence One General Ability or Several Specific Abilities?
Theories of Multiple Intelligences

Sternberg’s Three Intelligences
(academic problem-solving intelligence –
assessed using intelligence tests. Predicts school
grades well and not as well with vocational success.
 Creating intelligence – reacting adaptably to novel
situations and generating novel ideas.
 Practical intelligence – everyday tasks that may be ill
defined with multiple solutions. Seen most in business
 Analytical
Comparing Theories of Intelligence
What Makes Up Emotional Intelligence?

Distinct from academic intelligence is social intelligence – the know-how involved in comprehending social
situations and managing oneself successfully.

A part of social intelligence is emotional intelligence  the ability to perceive, understand, manage, and use
emotions.

Emotional intelligence should not include varied traits such as self-esteem and optimism
emotions – to recognize them in faces,
music, and stories.
 Understand emotions – to predict them and how they
change and blend.
 Manage emotions – to know how to express them in
varied situations.
 Use emotions for adaptive or creative thinking
 Perceive
Is Intelligence Neurologically Measurable?
Brain Size and Complexity

Fun fact! English Poet Lord Byron had a 5 pound brain, 2 pounds bigger than the normal size!

Fun fact! Beethoven's brain had exceptionally numerous and deep convolutions.

Fun fact! Einstein had a 15% larger lower parietal lobe – centre for mathematical processing
and spatial information. However, other regions seem to register a bit smaller. May be why
our most notable mathematicians were late bloomers (slow to talk, etc).

Fun fact! More educated people die with more synapses than uneducated people. Did they
seek education because they had more synapses or have more synapses because of their
education?

Unfortunately brain structure and size does not equal intelligence. Could it be genetics?
Environment? (rats in stimulating environments) Nutrition?

Neural plasticity may be the biggest link we have. The more mouldable the brain, the more
opportunity for new learning. Agile minds = agile brains.

Type of brain matter also may play a role – Grey Matter (neural cell bodies) VS White Matter
(axons and dendrites) More grey matter in memory, attention and language areas– higher
intelligence scores.
Is Intelligence Neurologically Measurable?
Brain Function

When people think about the questions on common intelligence tests, a
frontal lobe area just above the outer edge of the eyebrows becomes
especially active – left side for verbal questions and on both sides for spatial
questions.

Perceptual Speed – Intelligence and perceptual speed are closely correlated.
Experiment – stimulus picture flashed first, then masking image to override
the stimulus picture. Then asked if the right or left side was longer. The
length of time the stimulus is flashed is varied but people with higher
intelligence scores can tell which side is longer, with less time.

Neurological Speed – Neural speeds on simple tasks (pressing a button) have
been found to be faster in people who score higher on intelligence tests.
Assessing Intelligence
Origins of Intelligence Testing

Intelligence testing stemmed from understanding individual differences and seeing where
some people may exceed over others. Ex. What job are you best suited for?

English scientist Francis Galton had a fascination with measuring human traits. When his
cousin CHARLES DARWIN (Hello! Best family connection EVER!) proposed the idea that nature
chooses successful traits through natural selection, Galton wondered if it was possible to
measure natural ability and encourage those of higher ability to mate.

Galton measured 10,000 people at the 1884 London Exposition on the following traits:


Reaction Time

Sensory Acuity

Muscular Power

Body Proportions
What did he learn? Nothing. The measure did not correlate. There was no distinctive
difference between intelligent and average people.
Alfred Binet: Predicting School
Achievement

Intelligence testing became more modern, when at the turn of the century, France
passed a law that all children need to go to school.

This inevitably saw that some students were in need of different programing
separate from the ‘typical’ school experience.

Did not want the teachers to assess, because of bias. French government hired
Binet to tackle the problem.

Came up with the idea of mental age  a measure of intelligence test performance
devised by Binet; the chronological age that most typically corresponds to a given
level of performance. Thus, a child who does as well as the average 8-year-old is
said to have a mental age of 8.

Different from chronological age.

Binet’s goal was simply to identify students who required special attention. Did
not identify the ‘why’ but Binet speculated that it had to do with environment. He
also worried that his test would used to label children and limit their
opportunities.
Lewis Terman: The Innate IQ

Terman adapted the Binet test to expand beyond children and into the
teenage/adult years. Called it the Stanford-Binet Test  the widely used American
revision (by Terman at Stanford University) of Binet’s original intelligence test.

From these tests, we got the famous IQ (intelligence quotient) test  defined
originally as the ratio of mental age (ma) to chronological age (ca) multiplied by 100
(thus, IQ=ma/ca X 100). On contemporary intelligence tests, the average
performance for a given age is assigned a score of 100.

For example, a child who has the same mental and chronological age, would have
an IQ of 100. But an 8 year old who answers questions like a 10 year old would
have an IQ of 125.

This original test worked well for children, but not adults. Most modern IQ tests
(although not measuring IQ) represent the test takes performance relative to the
aver performance of others the same age. Average IQ? Between 85 and 115.

Used in WW1 to asses army recruits and immigrants to the US. Results showed
bias towards those with Anglo-Saxon heritage and reduced quotas of those
immigrating from Southern and Eastern Europe.

Terman believed that IQ testing would ‘ultimately result in curtailing the reproduction
of feeble mindedness and in the elimination of an enormous amount of crime,
pauperism (poverty) and industrial inefficiency.’ Eugenics? DISCUSS!
IQ Test? TO THE LAPTOPS!

http://www.free-iqtest.net/
Modern Tests of Mental Abilities

Tests are divided into 2 categories:

1) Achievement Tests  tests designed to assess what a person has learned.

Ex) Final AP Exam

2) Aptitude Tests  tests designed to predict a person’s future performance; aptitude is the
capacity to learn.

Ex) College Entrance Exam

Most widely used intelligence test is the Wechsler Adult Intelligence Scale (WAIS)  the WAIS
is the most widely used intelligence test; contains verbal and performance (nonverbal) subtests.
WISC is for children and has variants for each age group. (see picture)

Measures not only overall intelligence score, but separate scores for verbal comprehension,
perceptual organization, working memory and processing speed.

Provides clues to cognitive strengths and weaknesses that teachers/therapists can use to work
upon. Ex. Low language or verbal score combined with high scores in other areas can indicate
a reading/language disability.
Wechler Adult Intelligence Scale
To the Laptops! WAIS Time!

http://wechsleradultintelligencescale.com/

Similarities and differences between IQ and WAIS tests? DISCUSS!
Principles of Test Construction

The number of questions you answer correctly on an intelligence test will tell
us almost nothing. How those answers are compare with others performance
will tell us what we need to know.

In order to find comparisons, the tests need to be given to a representative
sample of people. Called standardization  defining meaningful scores by
comparison with the performance of a pretested group.

Group scores are then distributed on a normal curve  a symmetrical, bellshaped 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.
Normal Curve
Flynn Effect

Intelligence scores have been
improving over time. Higher scores
seen now than before.

Better testing? Better nutrition?
More education? More stimulating
environments? Less childhood
disease? Smaller families? More
parental investment?
Reliability

Tests need to have Reliability  the extent to which a test yields consistent
results, as assessed by the consistency of scores on two halves of the test, or
on retesting.

In order to check results, researchers retest people. May take the same test,
or split the test in half (evens vs odds) to see if they agree.

If they do, the test is reliable.

Most modern tests (ex. WISC) have a reliabilities of about +.9, very high.
Validity

High reliability does not ensure a test validity  the extent to which a test
measures or predicts what it is supposed to.

Ex. If you used an inaccurate tape measure to measure peoples heights, your test
would have a high reliability but a low validity.

2 Types:

1) Content Validity the extent to which a test samples the behavior that is of
interest.

Ex) A drivers road test has content validity because it samples tasks the driver
routinely faces.

2) Predictive Validity  the success with which a test predicts the behavior it is
designed to predict; it is assessed by computing the correlation between test scores
and the criterion behavior (also called criterion-related validity).

Ex) That a final exam should predict the criterion of future performance.
The Dynamics of
Intelligence
Stability or Change?

Are intelligence scores stable throughout life?

By age 4, scores on IQ tests seem to predict scores later on in adult life.

IQ scores stabilize by age 7.
Extremes of Intelligence – Low Extreme

Intellectual Disability  (formerly referred to as mental retardation) a condition of
limited mental ability, indicated by an intelligence score of 70 or below and difficulty
in adapting to the demands of life; varies from mild to profound.

1% of NA population meets this criteria, with males outnumbering females by 50%.

Some may have a physical cause, such as Down’s Syndrome  a condition of
intellectual disability and associated physical disorders caused by an extra copy of
chromosome 21.

Historically, raised at home, died young or worked in labor jobs, such as farming.

Last ½ of 20th century, swung to normalization.

Ex. Mainstreamed into classrooms, live at home, not allowed to execute for crimes
in US – cruel and unusual punishment designation.
Extremes of Intelligence
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 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
Extremes of Intelligence – High Extreme
Extremes of Intelligence – High Extreme
Terman’s study of gifted children – scored over 135 on IQ
test. Followed over the next 70 years. High number of
lawyers, doctors, professors, scientists and writers.
 Self-fulfilling prophecy – those labelled ‘ungifted’ may be
influenced to become so by denying them opportunities
for enriched education.
 Tracking students – placing them in groups based on
intelligence. Examples?
 Appropriate developmental placement – placed in
programs where they excel. Ex. Good at math, art, social
leadership, etc.

Genetic and Environmental Influences
on Intelligence

Intelligence runs in families but is also dependent on the environment.
 Identical twin studies – twins reared together have the same IQ test
numbers of someone who takes the test twice.
 Fraternal are less.
 Brain scans reveal that identical twins have the same amount of grey
matter and their brains are the same in areas associated with verbal and
spatial intelligence.

Polygenetic – genes for intelligence have been found on chromosomes.

Adoptive children studies – during childhood, adoptive children in the same
family tend to have similar scores – supports the environment argument.
However, as they become adults, the discrepancy between parents and
adoptive children grows.
Heritability
Environmental Influences

Early environmental influences
human enrichment – neglect in orphanages
lead to programs where adults rehabilitate babies by
teaching them language and basic skills.
 Targeted training - an enriched environment while in
infancy will not give babies a head start. Learn when
you learn!
 Tutored

Schooling and intelligence – best practices
Head Start – quality, funded preschool
programs.
 Project
Group Differences in Intelligence Test Scores
Gender Similarities and Differences







Spelling – females better spellers
Verbal ability – females have better verbal fluency and
remembering words.
Nonverbal ability – females are better at remembering and
locating objects/picture associations.
Sensation – females more sensitive to touch, taste and smell.
Emotion-detecting ability – females better.
Math and spatial aptitudes – same between 2 genders, but
males better at problem solving, females in computation.
Greater male variability – IQ scores vary more in males than in
female.
Group Differences in Intelligence Test Scores
Ethnic Similarities and Differences
Ethnic
similarities
Ethnic differences
Boils down to – ‘Grass grows
where you water it’.
The Question of Bias

Two meanings of bias
sense – intelligence tests are bias. Middle
class assumptions – cup goes with saucer, insurance
is bought to protect the home. May not be the same in
all classes.
 Scientific sense – hinges on test’s validity.
 Popular
Test-taker’s expectations – Will I do well or not?
 Stereotype threat  a self-confirming concern that
one will be evaluated based on a negative
stereotype.

HotHouse Babies