Psychology: Intelligence
I) What is Intelligence?
A) Intelligence is a type of cognitive ability (the capacity to reason,
remember, understand, solve problems, and make decisions) that deals
specifically with:
1) Information processing
2) Problem solving
3) Adaptability to new conditions
II) Intelligence testing
A) History:
1) Alfred Binet
(a) Made an age-graded test that compares a person’s mental vs.
chronological age
2) Lewis Terman (from Stanford University)
(a) Developed an English version of the test known as the
Stanford-Binet which expressed scores as single number Intelligence Quotient (IQ):
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IQ = (Mental Age / Chronological Age) * 100
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If Mental = Chronological Age, then IQ = 100
Therefore, 100 is the average IQ of individuals.
(b) Army Alpha (written)
(c) Army Beta (oral)
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B) Current methods:
1) David Wechsler
(a) WAIS (Wechsler Adult Intelligence Scale)
(b) WISC (Wechsler Intelligence Scale for Children)
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Includes verbal comprehension, perceptual reasoning,
working memory, & processing speed
(c) Global IQ - person’s score compared w/ others of same age
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“Average” = 100; “Normal range” – 85-115
2) Stanford-Binet includes:
(a) Fluid reasoning, Quantitative reasoning, Knowledge, Visualspatial processing, Working memory
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All of these have one verbal and one nonverbal subtest
C) Aptitude/Achievement tests:
1) Aptitude test
(a) Designed to measure capability to benefit from education or
training
(b) E.g., SAT, GRE
2) Achievement test
(a) Designed to measure level of knowledge, skill, or
accomplishment in a particular area
(b) E.g., GRE subject test
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III) Advantages and Components of Good Tests (tests are systematic
procedure for observing behavior in a standard situation and describing it
with the help of a numerical scale or category system)
A) Standardized: similar conditions for everyone taking test
B) Objective: no biases based on who gives/takes test
C) Norms: frequency of particular scores, this allows us to compare
scores between people
D) Remember Reliability? - Results are repeatable/stable:
1) Test-retest
i Person does the same test again
2) Alternate-form test
i Person does a similar test on another occasion
3) Split-half reliability
i Correlate two halves of the test
4) Correlation coefficient of +.80 or higher is reliable
E) Remember Validity? - Test measures what it is supposed to measure;
scores are interpreted correctly and used appropriately:
1) Content validity - Fair sample of content?
2) Criterion validity – Does the score on the test relate to some
other measure of what the test assesses?
3) Predictive validity - Predict future performance?
4) Construct validity - Actually measuring what you want?
5) IQ Tests seem to be pretty reliable (except for very young
children) and valid
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IV) Influences on IQ Scores - Intelligence is a developed ability
consisting of:
A) Genetics - Twin studies show that twins reared apart have highly
correlated intelligence
1) Half of the variability in IQ scores of a group of people can be
attributed to hereditary influences and half to environmental
influences
B) Environmental factors - Twin studies show that twins reared together
have the most highly correlated intelligence
1) Education
2) Culture (e.g., Race)
(a) More variability within the groups than between the groups
3) Socioeconomic status
(a) Parental jobs and status depend on IQ
(b) Income affects enriching value of environment
(c) Motivation
4) Culture revisited (Ethnic Differences)
(a) Often coupled with Socioeconomic status (SES) and social
support
(b) Stereotype Threat
i members of a group feel they will be evaluated in terms of
negative stereotypes about their group
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Creates test anxiety  lower scores
5) Nutrition
(a) Low nutrition is correlated with lower IQ
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6) Self-Fulfilling Prophecies
(a) Sometimes how intelligent we expect a person to be can cause
them to fulfill that prophecy!
V) Approaches to understanding intelligence
A) Psychometric approach
1) Emphasizes products of intelligence
2) Spearman’s g & s factors
(a) There is a general intelligence factor (g)
(b) And there are specific skills that rely on g (s)
(c) Some correlations couldn’t be explained by either g or s; these
are called group factors
3) Thurston’s 7 Primary Mental Abilities:
(a) Numerical ability, Reasoning, Verbal fluency, Spatial
visualization, Perceptual ability, Memory, & Verbal
comprehension
4) Cattell’s Fluid & Crystallized Intelligence
(a) Fluid intelligence - Basic power of reasoning & problem solving
(b) Crystallized intelligence - Specific knowledge gained as a
result of applying fluid intelligence
B) Information-processing approach
1) Mental processes/operations underlying intelligence
(a) Attention
(b) Processing speed
(c) Memory
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C) Triarchic theory of intelligence
1) Analytic Intelligence (BOOK SMARTS)
2) Creative Intelligence (OUTSIDE THE BOX)
3) Practical Ingelligence (STREET SMARTS)
D) Multiple (kinds of) intelligences
1) Gardner claims intelligences are independent of each other:
(a) Linguistic – vocab & reading comprehension
(b) Logical/math – arithmetic & reasoning
(c) Spatial – relationships between objects
(d) Musical – rhythm, tempo, sound identification
(e) Body-kinesthetic – dancing, athletics, hand-eye coordination
(f) Intrapersonal – self-understanding
(g) Interpersonal – understand and interact with others
(h) Naturalistic – see patterns in nature
(i) (emotional) – perceive emotions and link them to one’s thinking
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