Intelligence
Unit XI
Modules 60-64
Intelligence
• One of the biggest debates about intelligence is
about if intelligence is one aptitude or many
• In past research studies, intelligence has been
operationally defined as whatever intelligence
tests measure, which has tended to be school
smarts
• Intelligence is not a quality like height or weight
that has the same meaning to everyone around
the world
• People assign the term intelligence to the
qualities that enable success in their own time
and in their own culture *
Intelligence
• Intelligence- mental quality consisting of the
ability to learn from experience, solve
problems, and use knowledge to adapt to new
situations
• Intelligence test- a method for assessing an
individual’s mental aptitudes and comparing
them with those of others using numerical
scores *
Intelligence
• You probably know people that are really
talented at one or a few things, but struggle to
succeed in other areas in the most basic ways
• Are all these people intelligent even though
struggle badly in something?
• Can you rate someone’s intelligence on one
single scale or do you need several different
scales *
Intelligence
• Charles Spearman believed we have one general
intelligence
– (g)- 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
• In order to test the general intelligence,
Spearman helped develop factor analysis
– A statistical procedure that identifies clusters of
related items called factors on a test
– Used to identify different dimensions of performance
that underlie a person’s total score *
Intelligence
• Spearman found that those who score high in
one area like verbal intelligence usually score
higher than average in other areas such as spatial
or reasoning ability
• Spearman believed a common skill set, the g
factor, underlies all intelligent behavior
• L.L. Thurstone worked to disprove Spearman’s
idea of a g factor
• He identified seven clusters of primary mental
abilities
• He did not rank people on a single scale of
general aptitude *
Intelligence
• When other researchers studied Thurstone’s
seven clusters they found that those who excelled
in one of the seven clusters generally scored well
on the others
• This supported the idea of a g factor
• We can liken mental ability to physical ability
• Athleticism is not on thing but many
• Maybe there is a general athletic ability to allows
some to run fast and catch a ball well also
• These are two very different talents that some
people are equally good at *
Theories of multiple intelligences
• Howard Gardner views intelligence as multiple
abilities that come in different packages
• Brain damage can destroy one ability while
keeping others intact
• He looked at people with savant syndrome to
study his ideas
– Savant syndrome- a condition in which a person
otherwise limited in mental ability has an exceptional
specific skill, such as in computation or drawing *
Videos of Savant syndrome
Theories of multiple intelligences
• People with savant syndrome often score low on
intelligence tests but have an island of brilliance
• Some have virtually no language ability but can
compute numbers and figures as quickly as a
calculator
• Sometimes they can identify the day of the week
with a historical event
• About 4 in 5 who are savant are male and many
also have autism spectrum disorder *
Theories of multiple intelligences
• Using his studies about savant syndrome,
Gardner argued that we do not have an
intelligence but multiple intelligences
• If someone is talented at many things, its not
because they have a common intelligence trait
but instead they exhibit multiple intelligences
• Recent research has gone against Gardner and
supported the idea of a general intelligence *
Theories of multiple intelligences
• Recent studies have shown that the g factor does
matter and it predicts performance on various
complex tasks and in various jobs
• Success is not a one ingredient recipe
• High intelligence may help you get into a good
college but it wont make you successful once
there
• The recipe for success combines talent with grit
– Grit is passion and perseverance in the pursuit of long
term goals *
Theories of multiple intelligences
• Robert Sternberg agrees that there is more to
success than traditional intelligence and also
agrees with Gardner’s idea of multiple
intelligences
• Sternberg proposes a triarchic theory of three,
not eight, intelligences *
Theories of multiple intelligences
• Sternberg’s three intelligences are:
• Analytical intelligence- assessed by traditional
intelligence tests which present well defined
problems having a single right answer- such tests
can usually predict school grades fairly well
• Creative intelligence- demonstrated in reacting
adaptively to novel situations and generating
novel ideas
• Practical intelligence- required for everyday tasks,
which may be ill-defined with multiple solutionscan help predict managerial success *
Theories of multiple intelligences
• Sternberg has helped to develop new measures
of creativity that have been seen to be better at
predicting success of American students in their
first year of college with reduced ethnic-group
differences
• Gardner and Sternberg differ on some points but
they both agree that multiple abilities can
contribute to life success
• Under their influences, teachers are taught to
value a variety of learning styles and to apply
multiple intelligence theory to their classroom *
Emotional Intelligence
• Social intelligence is distinct from academic
intelligence
• Social intelligence is the know how involved in
successfully comprehending social situations
• People with high social intelligence can usually
properly read social situations and respond
accordingly
• Edward Thorndike first proposed the idea of
social intelligence
• Later psychologist found that people with high
IQs did not seem to be performing higher in
social situations *
Emotional Intelligence
• Emotional intelligence- the ability to perceive,
understand, manage, and use emotions
• A test has been developed to assess the four
emotional intelligence components:
– Perceiving emotions
– Understanding emotions
– Managing emotions
– Using emotions *
Emotional Intelligence
• Emotional intelligence is less a matter of
conscious effort than of one’s unconscious
processing of emotional information
• Those who score higher on emotional
intelligence tests usually enjoy higher quality
interactions with friends
• They may exhibit better job performance
• They tend to be able to stay away from
depression, anxiety, or anger *
Is Intelligence neurologically
measurable?
• Studies have shown there to be a correlation
of +.33 between brain size and intelligence
• What does this correlation mean?
• It does show a correlation to exist between
brain size and intelligence- the larger the brain
the higher the intelligence
• Remember its only a correlation *
Is Intelligence neurologically
measurable?
• Further brain imaging studies have shown that
intelligence is having ample gray matter(mostly
neural cell bodies) plus ample white
matter(axons) that make for efficient
communication between brain centers
• In some studies, like with Einstein’s brain, they
found certain areas of the brain to be larger than
normal
• In Einstein, his parietal lobe was 15 percent
larger- this area is the center for processing
mathematical and spatial information *
Is Intelligence neurologically
measurable?
• Brain scans also reveal that smart people use
less energy to solve problems
• Basically it has been seen that the brains of
smart people seem to work more efficiently
and more quickly *
Origins of intelligence testing
• Western cultures have pondered how and why
individuals differ in mental activity
• Francis Galton did a lot of research on human
traits
• Galton was Darwin’s cousin and Galton
wanted to see if he could test natural ability
• Galton would also suggest that people of high
ability mate together to rid the world of the
less diserable people- called eugenics *
Origins of intelligence testing
• Galton’s attempts to discover a way to
measure natural ability failed
• He did help create the nature vs nurture
argument that we still look at in psychology
today *
Origins of intelligence testing
• The modern intelligence testing movement began
at the beginning of the 20th century when France
passed a law requiring all children to attend
school
• Some of the children seemed incapable of
benefiting from the regular school curriculum and
in need of special classes
• The schools were in need of an objective way to
determine what kids were in need of the special
classes *
Alfred Binet
• The schools did not trust the subjective
judgments of teachers
• To minimize bias from teachers, France
commissioned Alfred Binet to study the
problem
• Binet assumed that all children follow the
same course of intellectual development but
that some develop more rapidly *
Alfred Binet
• A dull child should perform as does a typical
younger child on tests and a bright child should
perform as does a typical older child
• Binet wanted to measure a child’s mental age
– The chronological age that most typically corresponds
to a give level of performance
– A child who does as well as the average 8 year old is
said to have a mental age of 8
• If a 9 year old performs at the level of a typical 7
year old, they would struggle with age
appropriate schoolwork according to Binet *
Alfred Binet
• Binet would test a variety of reasoning and
problem solving questions on his daughters
and then on bright and backward Parisian
children- standardization for his tests
• By testing these children he identified items
that would predict how well French children
would handle their schoolwork *
Alfred Binet
• Professionally Binet did not make assumptions
concerning why a particular child was slow,
average, or advanced
• Personally Binet leaned more towards an
environmental reasons
• To raise the capacities of low scoring children
he recommended mental orthopedics that
would help develop their attention span and
self discipline *
Alfred Binet
• Binet believed his intelligence test did not
measure inborn intelligence but it did identify
French schoolchildren that needed special
attention
• Binet feared his tests would be used to label
children and limit their opportunities instead
of helping children that needed help *
Lewis Terman and IQ
• Soon after Binet’s death, people adapted his
tests for use as a numerical measure of
inherited intelligence
• Lewis Terman, a professor at Stanford, was
one of the first to do this
• Terman found that the Paris developed
questions and age norms did not work well
with California schoolchildren *
Lewis Terman and IQ
• Terman’s revision of Binet’s test would be called
the Stanford-Binet Intelligence Test
• For Terman, intelligence tests revealed the
intelligence with which a person was born
• William Stern would use the tests to develop the
intelligence quotient or IQ
– Defined originally as the ratio of mental age to
chronological age multiplied by 100(IQ=ma/ca X 100)
– On contemporary intelligence tests the average for
performance for a given age is assigned a score of
100, with scores assigned to relative performance
above or below average *
Lewis Terman and IQ
• What would an 8 year old who answers questions as
would a typical 10 year have for an IQ?
• 125
• The original IQ formula worked well for children but
not adults
• Today’s Stanford-Binet tests compute IQ differently
• The IQ scores represent the test takers performance
relative to the average performance of others the same
age
• 2/3 of people fall between 85 and 115 with 100 being
average *
Lewis Terman and IQ
• Terman agree with Galton’s ideas of eugenics
• He believed that intelligence tests would
ultimately result in curtailing the reproduction
of feeblemindness and in the elimination of an
enormous amount of crime and industrial
inefficiency
• With Terman’s help, the US government
developed new tests to evaluate both newly
arriving immigrants and WWI army recruits *
Lewis Terman and IQ
• The results of the tests indicated the
inferiority of people not sharing their AngloSaxon heritage
• This led to a 1924 immigration law that
reduced Southern and Eastern European
immigration quotas to less than 1/5 of those
for Northern and Western Europe
• Binet would have been horrified to see how
his tests were being used *
Modern Tests of Mental Ability
• Achievement tests- a test designed to assess
what a person has learned
– AP exams, final exams
• Aptitude test- a test designed to predict a
person’s future performance
– Aptitude is the capacity to learn
– College entrance exams
• Total scores on the US SAT correlated +.82 with
general intelligence scores in a national sample of
14 to 21 year olds *
Modern Tests of Mental Ability
• Wechsler Adult Intelligence Scale(WAIS)- contains
verbal and performance(nonverbal) subtests
– Most widely used individual intelligence test
– WISC- Wechsler Intelligence Scare for Children
– Includes 15 subtests including similarities, vocabulary,
block design, and letter number sequencing
– It yields an overall intelligence score and a separate
score for verbal comprehension, perceptual
organization, working memory, and processing speed
– Can show weaknesses in people to help know what
the student needs help in *
Test Construction
• To be widely accepted, psychological tests must
meet three criteria
– Standardized, reliable, and valid
• Just seeing how many questions you get right on
a test does not tell us anything
• We need a basis for comparing your score with
others’ performance
• Test-makers first give the test to a representative
sample of people to gain meaningful comparisons
*
Test Construction
• Your score is then compared to the scores of
others to see your position relative to others
• Standardization- defining uniform testing
procedures and meaningful scores by comparison
with the performance of a pretested 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
– The midpoint for intelligence is 100 *
Test Construction
• To keep the average score near 100, the
Stanford-Binet and Wechsler scales are
periodically restandardized
• Flynn effect- intelligence test performance has
been improving over time
– The cause of this increase is unknown *
Test Construction
• Reliability- the extent to which a test yields
consistent results as assessed by the consistency
of scores on two halves of the test, on alternate
forms of the test, or on retesting
• If the two scores generally agree the test is
considered to be reliable
• The higher the correlation between the testretest scores, the higher the test’s reliability
• The Stanford-Binet and WAIS have a reliability of
+.9 *
Test Construction
• High reliability does not ensure a test’s validity
• Validity- the extent to which a test measures
or predicts what it is supposed to
• If you use an inaccurate tape measure to
measure people’s heights, your height report
would have high reliability but low validity
• Content validity- the extent to which a test
samples the behavior that is of interest *
Test Construction
• The road test for a driver’s license has content
validity because it samples the tasks a driver
routinely faces
• 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 *
Test Construction
• The predictive power of aptitude tests is fairly
strong in the early school years, but later it
weakens *
Stability or Change?
• How stable are people’s intelligence scores
throughout their lives?
• Do people gradually decline intellectually as we
do physically?
• In cross sectional studies researchers are able to
test and compare people of various ages at one
time
• In these studies, researchers have consistently
found that older adults give fewer correct
answers on intelligence tests than do younger
adults *
Stability or Change?
• Wechsler stated that he thought the decline of
mental ability with age was a part of the
general aging process of the organism(human)
as a whole
• For a long time, his opinion was not
challenged
• Corporations established mandatory
retirement policies, assuming companies
would benefit from replacing old workers with
young ones *
Stability or Change?
• In the 1920s, some psychologists decided to
study college students longitudinally
• They retested the same cohort over a period
of years
– Cohort- a group of people from a given time
period
• They found that until late in life, intelligence
remained stable
• In some cases it even increased *
Stability or Change?
• Why the difference in the two studies?
• The cross sectional studies were studying 2
groups of people from different ages but also
different eras
• They compared less educated people from the
early 1900s with better educated people born
after 1950
– They also looked at people raised in large families
compared to smaller families
– People in less affluent homes to people raised in more
affluent homes *
Stability or Change?
• With the new findings, the idea that
intelligence sharply declines with age was
found to not be accurate
• They also found possible problems in the
longitudinal studies
• Those that survived to be retested were those
that were bright and healthy so they were
most likely to survive the study *
Stability or Change?
• Crystallized intelligence- our accumulated
knowledge and verbal skills
– Tends to increase with age
• Fluid intelligence- our ability to reason
speedily and abstractly
– Tends to decrease during late adulthood
• So basically our intelligence increases and
decreases depending on the type of
intelligence that is being tested 8
Extremes of Intelligence
• At one extreme of the normal curve are those
with unusually low intelligence test scores
• Intellectual disability- a condition of limited
mental ability, indicated by an intelligence score
of 70 or below and difficulty in adapting to the
demands of life- formerly called mental
retardation
• Performance is usually two standard deviations
below average
• Intellectual disability is usually apparent before
age 18 *
Extremes of Intelligence
• Down syndrome- a condition of mild to severe
intellectual disability and associated physical
disorders caused by an extra copy of
chromosome 21 *
Extremes of Intelligence
• Terman studied a large population of children
in California that IQ scores were over 135
• Terman found the children to be healthy, well
adjusted, and unusually successful
academically
• Before his studies people thought they were
maladjusted *
Extremes of Intelligence
• Many people question the assumptions of the
“gifted and talented” programs in schools
• One is the belief that only 3 to 5 percent of
children are gifted and that it pays to identify and
track these special few
• Tracking- segregating them in special classes and
giving them academic enrichment not available to
their peers
• Critics say tracking by aptitude often creates a
self-fulfilling prophecy *
Twin and adoption studies
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Intelligence does run in families
Is this nature or nurture?
How can you study this issue?
Twin and adoption studies
The intelligence test scores of identical twins
raised together are virtually as similar as those of
the same person taking the same test twice
• The scores of fraternal twins are much less similar
Twin and adoption studies
• Heritability- the proportion of variation among
individuals that we can attribute to genes
• The heritability trait may vary, depending on
the range of populations and environments
studied
Group differences in intelligence test
scores
• Stereotype threat- a self-confirming concern
that one will be evaluated on a negative
stereotype
• In a study, when African-American students
were reminded of their race before taking a
verbal test, they performed worse
• While taking a test, if you are worried about
the stereotype that your group does not
perform well, it may affect your performance