Intelligence
What is intelligence?
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Varies by culture
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Western cultures focus on cognitive tasks
Test performance is influenced by cultural
experiences
Is your “IQ” from nature or nurture?
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IQ and genetic effects (Genetics effects IQ)
IQ partly based on heredity
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Identical twins reared separately have more
similar IQ than fraternal twins reared together.
Is your “IQ” nature or nurture?
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IQ and birth parents (Childrearing effects IQ)
Is your IQ one general ability or
several specific abilities?
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Factor analysis
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Used to determine if intelligence is one or a cluster
of traits
Clusters: verbal, mathematical, spatial, reasoning
abilities
General intelligence
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Spearman’s “G” factor
A general capacity that underlies all specific mental
abilities
What types of intelligence are
there?
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Emotional
Cognitive
Unique
What is emotional intelligence?
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Ability to express, understand, and process
emotions
Being very empathic
What is cognitive intelligence?
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Math
Reading comprehension
What is unique intelligence?
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Savant Syndrome
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Incredible ability in one area

Numbers, drawing, music, memory
Savants are often autistic or
have other developmental
disability with a very
unusual talent in one area.
Stephen Wiltshire: The Human
Camera –
Drawn after one heliocopter ride
over New York
Do you remember?
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How does culture effect IQ scores?
How do we know IQ is partly based on heredity?
What is emotional intelligence?
What is cognitive intelligence?
What is the savant syndrome?
How did intelligence testing begin?
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Originally designed to measure cognitive aptitude
Alfred Benet
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Predicted school achievement with mental age
Eg. A 9 year old child has a mental age of 9
Lewis Terman (From Stanford University)
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Created the American revision of Binet’s original
intelligence test
Developed the “Stanford-Binet” IQ test
What is the intelligence Quotient
(IQ)?
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Mental age divided by chronological age X 100
E.g. 15 divided by 15 X 100 = 100
10 divided by 8 X 100 = 125
Worked well for children but not adults
Today’s IQ tests compare the person’s
performance to others of his own age (100 is
average)
What standard intelligence
tests are there?

WAIS
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Wechsler Adult Intelligence Scale
WISC
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Wechsler Intelligence Scale for Children
Other tests

Achievement tests - Measure what has been
learned
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Calculus test
Aptitude tests - Predicting ability

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A test of your capacity to learn
College entrance exams ( SAT & GRE exams)
Do you remember?
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How do you calculate IQ based on the older
method?
What was the problem with this method?
What is the difference between achievement tests
and aptitude tests?
What should you look for when
creating tests?
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Validity
Reliability
Standardization
What is validity?
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Measuring what it is supposed to measure

Content validity
College exams
 Driver’s license exam


Criterion validity
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Test compared to criterion group

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(e.g. depressed patients)
Predictive Validity
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SAT & GRE exams
What is reliability?
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Consistent results
Internal consistency

Odd v.s. even questions
What is standardization?


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Scores relative to
a pre-tested
group
Based on a bell
shaped normal
curve
Ave. a score of
intelligence test =
100
Do you remember?
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If a test has validity, what does that mean?
If a test has reliability, what does that mean?
Discuss the three types of validity?
What is standardization, and how did that change
the meaning of IQ?
What is the concept of the normal bell curve that
IQ is based on?