Intelligence

The capacity to understand the world, think
rationally, and use resources effectively when
faced with challenges
History: defining & measuring
intelligence

Sir Francis Galton (1822-1911)
genes & family lines
 Cousin of Charles Darwin
 intelligence = biological capacity
 Eugenics



The study of human heredity patterns with the
goal of improving the species through
selective breeding
reaction times & sensory acuity

later research contradicted these measures
History: defining & measuring
intelligence

Alfred Binet (1857-1911)
Binet-Simon Test France, 1905
 intelligence = collection of higher-order
mental abilities loosely related to one
another
 intelligence is nurtured
 mental age

History: defining & measuring
intelligence

Charles Spearman (1863-1945)




liked Binet’s methods of testing
liked Galton’s idea that intelligence was a single
entity
developed “factor analysis”
two factors



“g” = general intelligence
“s” = specific ability
score on any given test depends on a combination of
these 2 factors


g accounts for the similarity in test results
s accounts for the differences in test results
History: defining & measuring
intelligence

Raymond Cattell (1905 - maybe)
student of Spearman’s
 modified Spearman’s intelligence theory
 thought that general intelligence was not
one factor but two

Cattell’s Fluid & Crystallized
Intelligence

Fluid intelligence
ability to perceive relationships without
previous specific experience
 matrices tests or verbal analogies
 Ability to learn new info quickly
 Speed of mental processing
 Reasoning and problem solving


Lose as you age
Cattell’s Fluid & Crystallized
Intelligence

Crystallized intelligence

mental ability derived from previous
experience
word meanings
 use of tools
 cultural practices


Gain as you age
Robert Sternberg

Proposed a Triarchic Theory of Intelligence

Componential Intelligence



Experiential Intelligence


Includes metacomponents, performance components, and
knowledge acquisition components
Analyzing information to solve problems
Ability to deal with novelty and automatize processing by
using prior experiences
Contextual Intelligence

Practical Intelligence and social intellgence


Common sense
Dealing with day to day issues and demands
Howard Gardner’s 8 Intelligences
Naturalist*

- the ability to recognize and classify plants, minerals,
and animals, including rocks and grass and all variety
of flora and fauna, and to recognize cultural artifacts
like cars and sneakers. Possible vocations that use the
naturalist intelligence include conservation, biologist,
teacher, lobbyist, and park service. *Because this is a
recent addition to the Intelligences, we have not yet
included it in the Multiple Intelligence Tests our site
features.
Musical

- the ability to understand and develop musical
technique, to respond emotionally to music and to
work together to use music to meet the needs of
others, to interpret musical forms and ideas, and to
create imaginative and expressive performances and
compositions. Possible vocations that use the musical
intelligence include technician, music teacher,
instrument maker, choral, band, and orchestral
performer or conductor, music critic, aficionado,
music collector, composer, conductor, and individual
or small group performer.
Logical-Mathematical

- the ability to use numbers to compute and describe,
to use mathematical concepts to make conjectures, to
apply mathematics in personal daily life, to apply
mathematics to data and construct arguments, to be
sensitive to the patterns, symmetry, logic, and
aesthetics of mathematics, and to solve problems in
design and modeling. Possible vocations that use the
logical-mathematics intelligence include accountant,
bookkeeper, statistician, trades person, homemaker,
computer programmer, scientist, composer, engineer,
inventor, or designer.
Existential
Interpersonal

- the ability to organize people and to communicate
clearly what needs to be done, to use empathy to help
others and to solve problems, to discriminate and
interpret among different kinds of interpersonal clues,
and to influence and inspire others to work toward a
common goal. Possible vocations that use the
interpersonal intelligence include administrator,
manager, politician, social worker, doctor, nurse,
therapist, teacher, sociologist, psychologist,
psychotherapist, consultant, charismatic leader,
politician, and evangelist.
Bodily-Kinesthetic

- the ability to use the body and tools to take effective
action or to construct or repair, to build rapport to
console and persuade, and to support others, to plan
strategically or to critique the actions of the body, to
appreciate the aesthetics of the body and to use those
values to create new forms of expression. Possible
vocations that use the bodily-kinesthetic intelligence
include mechanic, trainer, contractor, craftsperson,
tool and dye maker, coach, counselor, salesperson,
sports analyst, professional athlete, dance critic,
sculptor, choreographer, actor, dancer or puppeteer.
Linguistic

- the ability to use language to describe events,
to build trust and rapport, to develop logical
arguments and use rhetoric, or to be expressive
and metaphoric. Possible vocations that use
linguistic intelligence include journalism,
administrator, contractor, salesperson, clergy,
counselors, lawyers, professor, philosopher,
playwright, poet, advertising copywriter and
novelist.
Intrapersonal

- the ability to assess one's own strengths,
weaknesses, talents, and interests and use them to set
goals, to understand oneself to be of service to others,
to form and develop concepts and theories based on
an examination of oneself, and to reflect on one's
inner moods, intuitions, and temperament and to use
them to create or express a personal view. Possible
vocations that use the intrapersonal intelligence
include planner, small business owner, psychologist,
artist, religious leader, and writer.
Spatial

the ability to perceive and represent the visual-spatial
world accurately, to arrange color, line, shape, form
and space to meet the needs of others, to interpret and
graphically represent visual or spatial ideas, to
transform visual or spatial ideas into imaginative and
expressive creations. Possible vocations that use
spatial intelligence include illustrator, artist, guide,
photographer, interior decorator, painter, clothing
designer, weaver, builder, architect, art critic,
inventor, or cinematographer.
Modern intelligence tests

The Stanford-Binet Scale
modification of the original Binet-Simon,
after original came to US
 intelligence quotient (IQ) = child’s mental
age divided by child’s chronological age
 Mental age of 12 and chronological age of 9



IQ = 133
used widely in the US, not as much as
previously
Modern intelligence tests

The Wechsler tests
used more widely now than Stanford-Binet
 modeled after Binet’s, also made adult test

WISC-III for children
 WAIS-III for adults

Standardized scoring of
Wechsler tests
¶ All raw scores converted to
Number of score
standardized scores
¶ Normal distribution
¶Mean of 100
¶Standard deviation of 15
68.26%
95.44%
0.13%
0.13%
2.14%13.59%34.13%34.13%13.59%2.14%
50
70
85
100
115
130
145
Mental Retardation

A significant below average level of
intellectual functioning which occurs with
related limitations in two or more skill areas
Levels of Retardation

Mild


Moderate

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IQ ranges from 40-54 with limited independence and
limited skills to handle daily situations
Severe


IQ ranges from 55-69 with the ability to function
independently and can handle most daily situations
IQ ranges from 25-39 with very little independence
and little ability to handle daily situations
Profound

IQ ranges below 25 and lacks any independent control
Causes of Retardation

Down’s Syndrome

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Familial retardation

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Extra chromosome
Greater probability in older mothers
Family history with no biological causes such as lead
in the water
Organic

Damage to the brain caused by physical trauma,
illness, viruses, loss of oxygen or poisoning
Gifted

Gifted/Superior IQ


Range from 130-144
Genius


Range above 145
Lewis Terman longitudinal study on the genius has
shown that those with high IQ are on the average
better adapted and more successful than average IQs
How valid are IQ tests?



Validity = test measures what it’s intended to
measure
Does test correlate with other measures of same
construct?
School achievement




IQ tests (I.e., S-B and the Wechsler) correlate highly
but they were designed to test stuff that you learn in school
Prestigious positions
On-the-job performance & other work-related
variables
Types of Validity

Content Validity


Criterion Validity


Compares test scores to actual performance on
another direct and independent measure to what the
test is suppose to measure
Predictive Validity


Test’s ability to cover the range of material (content
that it is to measure
How well a test score predicts an individuals
performance in the future
Face Validity

How relevant test items and test appear
Reliability

Consistently measures what it is suppose to
measure

Test – retest reliability


Split-half reliability


Take a test on one day and a week later test again and score
the same
Your score on the first half of the test should be similar to
the second half of the test
Equivalent forms reliability

Two different but similar test scores should be similar
Norms


Average score based on a sample
Standards of test performance that permit the
comparison of one person’s score on a test to the
scores of others who have taken the same test
Standardization


Establishes same guidelines for testing such as
time limits, same instructions and same level
of test
It allows for comparing different individuals
abilities
Other Types of Tests

Achievement Tests



Measure your level of knowledge of learned
material
Normal school tests
Aptitude Tests

Designed to predict ability in a particular ability or
line of work
Nature vs. Nurture in IQ


Are differences between people due to
environmental or genetic differences?
Misunderstanding the question



“Is a person’s intelligence due more to genes or to
environment?”
no genes = no intelligence
both genes & intelligence crucial for any trait
Heritability &
Environmentality

Heritability


degree to which variation in trait stems from
genetic, rather than environmental, differences
among individuals
Environmentality

degree to which variation is due to environmental
rather than genetic differences
The Heritability Coefficient





Single number, ranging from 0 to 1.0
Represents amount of trait due to genetic
differences
0 means no variance due to genetics
1 means all variance due to genetics
.30 means 30% is due to genetic
differences, 70% due to environmental
Twin Studies & Family Influence

If trait genetic:


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closely related more similar than less closely related
Many close relatives share environments too
Types of studies to separate effects



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monozygotic twins reared together
monozygotic twins reared apart
siblings/dizygotic reared together
siblings/dizygotic reared apart
adoptive siblings reared together
Family Influence on IQ
Transient
influence of
family in which
you are raised


adoptive siblings as
children and adults
identical vs.
fraternal twins
reared together
1
Correlation coefficient

Identical twins
0.8
Fraternal twins
0.6
0.4
0.2
0
4-5
6-11 12-15 16-19 Adult
Age group
IQ Differences among
Racial/Cultural Groups

Find differences among racial & cultural
groups on IQ


American Blacks score about 15 points lower
than Whites
WHY?

genetics?



Witty & Jenkins (1935)
No support for genetic differences
environment?
IQ Differences among
Racial/Cultural Groups




Each wheat field planted from same
package of genetically diverse seeds
One field is quite fertile, the other is not
Within each field, differences due to
genetics
Between each field, differences due to
environment (fertility)
Why differences between
Blacks & Whites?

Social designation influences

autonomous minorities


immigrant minorities



deliberately separate themselves
came to country to better lives
see selves as better than those left behind
involuntary minorities



did not choose minority status
routinely judged as inferior by dominant majority
cross-cultural findings on IQ scores
Historical increase in IQ




Improved
performance on IQ
tests over the years
IQ
Big increases in tests Scores
assessing fluid
intelligence, smallest
in factual knowledge
Increased schooling
only accounts for
small portion of this
increase
Due to changes in the
culture?
105
100
95
90
85
80
75
70
1910 1920 1930 1940 1950 1960 1970 1980 1990
Year
Summary

Nature vs. nurture debate



Racial & cultural differences in IQ



heritability vs. environmentality
studies of twins & family influence
why we can’t interpret differences as due to
genetics
what we can attribute the differences to
Historical increase in IQ scores