Intelligence
A.P. Psych
Information adapted from: http://www.lbusd.k12.ca.us/millikan/Teacher_folder/HawkinsS/AdPlPsychology2.htm
Origins of Intelligence Testing
 Intelligence Test
 a method of assessing an individual’s
mental aptitudes and comparing them to
those of others, using numerical scores
Origins of Intelligence Testing
 Mental Age
 a measure of intelligence test performance
devised by Binet
 chronological age that most typically
corresponds to a given level of performance
 child who does as well as the average 8-yearold is said to have a mental age of 8
Origins of Intelligence Testing
 Stanford-Binet
 the widely used American revision of Binet’s
original intelligence test
 revised by Terman at Stanford University
 Terman added items to measure adult
intelligence
 He also revised a method of scoring by
developing the IQ or intelligence quotient
 From this method of scoring came the IQ Test
Origins of Intelligence Testing
 Intelligence
Quotient (IQ)
 defined originally the
ratio of mental age (ma)
to chronological age (ca)
multiplied by 100
 IQ = ma/ca x 100)
 on contemporary tests,
the average
performance for a given
age is assigned a score
of 100
What is Intelligence?
 Intelligence
 ability to learn from experience, solve problems, and
use knowledge to adapt to new situations
Assessing Intelligence
 Aptitude Test
 a test designed to predict a person’s future
performance
 aptitude is the capacity to learn
 Achievement Test
 a test designed to assess what a person has learned
 Wechsler Adult Intelligence Scale (WAIS)
 most widely used intelligence test
 subtests
 verbal
 performance (nonverbal)
Assessing Intelligence
 Standardization
 defining meaningful scores by comparison with
the performance of a pretested “standardization
group”
 Normal Curve
 the symmetrical bell-shaped 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
Getting Smarter?
The Normal Curve
Assessing Intelligence
 Reliability
 the extent to which a test yields consistent
results
 assessed by consistency of scores on:
 two halves of the test
 alternate forms of the test
 retesting
 Validity
 the extent to which a test measures or predicts
what it is supposed to
Reliability v. Validity
Reliability and Validity of IQ Tests
Reliability:
Problem before age 7.
For teenagers and adults, reliability is high.
Validity:
Can only be assessed for specific purposes.
Reasonably good for predicting success in
school and many occupations.
Assessing Intelligence
 Content Validity
 the extent to which a test samples the behavior
that is of interest
 driving test that samples driving tasks
 Criterion
 behavior (such as college grades) that a test
(such as the SAT) is designed to predict
 the measure used in defining whether the test
has predictive validity
Assessing Intelligence
Evidence about a test’s validity:
Content validity
Criterion validity
Predictive validity
Construct validity
Concurrent validity
Genetic Influences
Genetic Influences
 Heritability
 the proportion of variation among individuals
that we can attribute to genes
 variability depends on range of populations and
environments studied
Genetic Influences
Understanding Intelligence
 Psychometric Approach – emphasizes the
products of intelligence (IQ scores)
Spearman’s g: scores on almost all tests of cognitive
abilities were positively correlated
 g = cognitive ability, s = special intelligences
Thurstone: factor analysis – found seven independent
primary mental abilities
Cattell: two types of g
 Fluid intelligence – reasoning & problem solving
 Crystallized intelligence – specific knowledge gained as a
result of fluid intelligence
Understanding Intelligence
Information-Processing Approach –
analyzes the process of intelligent
behavior rather than the product
Applies the basic mental processes of
perception, learning, memory, and thought to
the concept of intelligence
Understanding Intelligence
 Triarchic Theory – Sternberg
 3 kinds of intelligences:
1. Analytic – problem solving, measured by IQ tests
2. Creative – composing music, art
3. Practical – survival skills
 Broadens the concept of intelligence and
emphasizes what it means in everyday life
Understanding Intelligence
 Multiple Intelligences – Gardner
1.
2.
3.
4.
5.
6.
7.
8.
Linguistic
Logical-mathematical
Spatial
Musical
Body-kinesthetic
Intrapersonal
Interpersonal
Naturalistic
Diversity in Cognitive Abilities
 Creativity – the ability to produce new, highquality ideas or products
 Divergent thinking – the ability to think along many
paths to generate many solutions to a problem
 3 kinds of cognitive and personality characteristics
necessary for creativity:
1. Expertise
2. Set of creative skills
3. Motivation

No strong correlation b/w IQ and creativity scores
 Creativity requires divergent thinking and IQ tests
assess convergent thinking (the ability to apply logic to
narrow down the # of possible solutions)
Unusual Cognitive Abilities
 Giftedness –
high IQs
don’t necessarily share same cognitive abilities
Have more of the basic cognitive abilities seen in all
children
 Mental Retardation
IQ less than 70 and who fail to display skill at daily living
and communication
 Down syndrome – extra chromosome
 Fragile X syndrome –defect on chromosome 23
 Environmental conditions – head injury, exposure to
alcohol or toxins
 Familial retardation
Deficient in metacognition
The Dynamics of Intelligence
Unusual Cognitive Abilities (con’t)
Learning Disabilities
Dyslexia – letters appear disjointed or jumbled
Dysphasia – difficulty understanding spoken
words or recalling words
Dysgraphia – problems with writing
Dyscalculia – difficulty with arithmetic