Intelligence
Defining Intelligence
Intelligence
An inferred characteristic of an individual,
usually defined as the ability to profit from
experience, acquire knowledge, think abstractly,
act purposefully, or adapt to changes in the
environment.
g factor
A general intellectual ability assumed by many
theorists to underlie specific mental abilities and
talents.
Psychometrics
The measurement of:
Mental abilities
Traits
Processes
The Invention of IQ Tests

In 1905 the French psychologist Alfred Binet published
the first modern intelligence test called the Binet-Simon
intelligence scale.
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His principal goal was to identify students who needed
special help in coping with the school curriculum.
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Along with his collaborator Theodore Simon, Binet
published revisions of his intelligence scale in 1908 and
1911, the last appearing just before his untimely death,
at the age of 54.
The Invention of IQ Tests

In 1912, the German psychologist William Stern coined
the abbreviation "I.Q.," a translation of the German
Intelligenz-Quotient ("intelligence quotient"), proposing
that an individual's intelligence level be measured as a
quotient of their estimated "mental age" and their
chronological age.
I Q = 100 x Mental Age/Chorological Age

A further refinement of the Binet-Simon scale was
published in 1916 by Lewis M. Terman, from Stanford
University, who incorporated Stern's proposal, and this
Stanford-Binet Intelligence Scale formed the basis for
one of the modern intelligence tests that remains in
common use.
Wechsler Scales

In 1939 David Wechsler published the first
intelligence test explicitly designed for an adult
population, the Wechsler Adult Intelligence
Scale, or WAIS.

Subsequent to the publication of the WAIS,
Wechsler extended his scale for younger ages,
creating the Wechsler Intelligence Scale for
Children, or WISC.
Wechsler Scales

The Wechsler scales contained separate
sub-scores for verbal and performance IQ,
thus being less dependent on overall
verbal ability than early versions of the
Stanford-Binet scale.
14 subtests of the WAIS-III
7 Verbal and 7 Performance

Verbal subtests
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Information
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Comprehension
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The degree to which one has learned, been able to comprehend and verbally express vocabulary (e.g.
What is a guitar?)
Digit span
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Abstract verbal reasoning (e.g. In what way are an apple and a pear alike?)
Vocabulary

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Concentration while manipulating mental mathematical problems (e.g. How many 45c. stamps can you
buy for a dollar?)
Similarities

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Ability to deal with abstract social conventions, rules and expressions (e.g. What does "Kill 2 birds with
1 stone" metaphorically mean?)
Arithmetic

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Degree of general information acquired from culture (e.g. Who is the president of Russia?)
Attention and concentration (e.g. given the sequence of digits '123', reverse the sequence.)
Letter-Number Sequencing

Attention and working memory (e.g. Given Q1B3J2, place the numbers in numerical order and then
the letters in alphabetical order)
14 subtests of the WAIS-III
7 Verbal and 7 Performance

Performance subtests

Picture Completion

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Digit Symbol — Coding

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Visual perception, speed
Object Assembly

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Logical/sequential reasoning, social insight
Symbol Search
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Nonverbal abstract problem solving, inductive reasoning, spatial reasoning
Picture Arrangement

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Spatial perception, visual abstract processing & problem solving
Matrix Reasoning

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Visual-motor coordination, motor and mental speed
Block Design

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Ability to quickly perceive visual details
Visual analysis, synthesis, and construction
Optional post-tests include Digit Symbol - Incidental Learning and Digit Symbol - Free Recall.
Wechsler Scales

Was the first intelligence scale to base
scores on a standardized normal
distribution rather than an age-based
quotient.
Gaussian Bell Curve
Normal Distribution
IQ Scores Distributed Normally
Very high and very low scores are rare.
68% of people have IQ scores between 85 and 115
99.7% between 55 and 145
Below-average Cognitive Ability

Profound mental retardation - Below 20

Severe mental retardation - 20–34

Moderate mental retardation - 35–49
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Mild mental retardation - 50–69
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Borderline mental retardation - 70–79
More on Mental Retardation


Children with mental retardation may learn to sit up, to
crawl, or to walk later than other children, or they may
learn to talk later.
Both adults and children with mental retardation may
also exhibit the following characteristics:
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Delays in oral language development.
Deficits in memory skills.
Difficulty learning social rules.
Difficulty with problem solving skills.
Delays in the development of adaptive behaviors such as selfhelp or self-care skills.
Lack of social inhibitors.
More on Mental Retardation
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Mental retardation affects approximately 1-3% of the population in
developed countries.
Until recently, a significant proportion of individuals with mental
retardation were cared for in residential facilities such as state-run
training schools.
The recent trend has been to move individuals who are mentally
disabled out of institutional settings and into more community-based
living arrangements such as group homes.
This trend underscores the idea that mental retardation cannot be
categorized as a mental illness in the strictest sense of the term.
Thus, these individuals should be viewed as a population requiring
more-than-average help in the daily chores of living.
Risk Factors
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Infections (Rubella, Toxoplasmosis, HIV, Herpes, etc.)
Chromosomal abnormalities (Down Syndrome and others)
Environmental (Deprivation Syndrome)
Genetic abnormalities and inherited metabolic disorders (PKU)
Metabolic (Hypoglycemia due to uncontrolled diabetes)
Nutritional (Malnutrition)
Toxic (Alcohol, street, Rx & over the counter drugs, lead, mercury)
Trauma (before and after birth)
Unexplained (this largest category is for unexplained occurrences
of mental retardation, about 75 % of all cases)
Prevention

Genetic

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Prenatal screening for genetic defects and genetic counseling for families at risk
for known heritable disorders.
Social

Government programs to ensure adequate nutrition to the underprivileged during
prenatal months and most critical years of life.
 Early intervention in situations involving abuse and deprivation.
 Early testing and proper diet for PKU.
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Toxic
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Environmental programs to reduce exposure to lead, mercury, and other toxins.
Increased public awareness of the risks of alcohol and drugs during pregnancy.
Infectious
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Prevention of congenital rubella syndrome.
Increased public awareness on the risk of HIV, Herpes, and other infections.
Limiting exposure to cat litter that can cause toxoplasmosis .
More on Mental Retardation

Of individuals with mental retardation, an
estimated 40-70% have diagnosable
psychiatric disorders.

The Burton Blatt Institute at Syracuse
University works to advance the civic,
economic, and social participation of
people with disabilities.
Can IQ tests be culture free?
Attempts to make IQ tests culture fair or culture
free have backfired because different cultures
have different problem-solving strategies.
Culture affects a person’s. . .
Attitude toward exams
Comfort in settings required for testing
Motivation
Rapport with test provider
Competitiveness
Ease of independent problem solving
Expectations and IQ
Scores are affected by expectations for
performance.
Expectations are shaped by stereotypes.
Stereotype threat:
Burden of doubt one feels about his/her performance
due to negative stereotypes about his/her group.
Stereotype threat affects African-Americans,
Latinos/Latinas, low-income people, women, and the
elderly.
Sternberg’s Triarchic Theory
Componential (analytic)
Comparing, analyzing, and evaluating.
This type of process correlates best with IQ.
Experiential (creative)
Inventing solution to new problems.
Transfer skills to new situations.
Contextual (practical)
Applying the things you know to everyday contexts.
Emotional intelligence
Ability to identify your own and other people’s
emotions accurately.
Ability to express your emotions clearly.
Ability to manage emotions in self and others.
Appears to be biologically based (Damasio,
1994).
The Psychometric and Cognitive
Approaches to Intelligence
Motivation and
intelligence

Comparing 100 most successful men with
100 least successful, researchers found that
motivation, not IQ, made the difference.

Motivation to work hard at intellectual tasks
differs as a function of culture.

American children are as knowledgeable as
Asian children on general skills.
Asian parents, teachers, and
students are more likely to believe
that math ability comes from
studying.
Americans are more likely to view
math and other abilities as innate.
American parents had lower
academic standards for kids.
American children value education
less.