Intelligence

What makes us smart?Or not so smart?

Theories of Intelligence

• No one real definition

• Fluid versus Crystallized Intelligence

• 4 main theoretical concepts of intelligence….

Charles Spearman and his G factor

• Used factor analysis and discovered that what we see as many different skills is actually one General Intelligence.

• If you are good at one subject you are usually good at many others.

Jack Bauer is good at torturing, bomb defusing, shooting, figuring out evil plots and saving the country (and he is good looking). Is there anything he cannot do?

Howard Gardner and Multiple Intelligences

• Gardner believed that there exists at least 7 different types of intelligences.

1. Linguistic2. Logical-mathematical3. Spatial4. Musical5. Body-kinesthetic6. Intrapersonal7. Interpersonal8. Naturalist

Robert Sternberg and his Triarchic Theory

• Most commonly accepted theory today.

• Three types of intelligence

1.Analytical2.Creative3.Practical

Goleman and his EQ

• Emotional Intelligence

• Interpersonal and intrapersonal intelligences.

• Maybe EQ is a better predictor for future success than IQ.

Brain Size and IntelligenceIs there a link?

• Small +.15 correlation between head size and intelligence scores (relative to body size).

• Using an MRI we found +.44 correlation with brain size and IQ score.

Brain Function and Intelligence

• Higher performing brains are less active than lower performing brains (use less glucose).

• Neurological speed is also a bit quicker.

How do we Assess Intelligence?

• Alfred Binet and Theodore Simon set out to figure out a concept called a mental age (what a person of a particular age should know).

• They discovered that by discovering someone’s mental age they can predict future performance.

• Hoped they could use test to help children, not label them.

Terman and his IQ Test

• Used Binet’s research to construct the modern day IQ test called the Stanford-Binet Test.

• IQ=Mental age/Chronological age X 100.

• A 8 year old has a mental age of 10, what is her IQ?

• A 12 year old has the mental age of 9, what is his IQ?

• A boy has the mental age of 10 and an IQ of 200, how old is he?

Intelligence Tests

• Binet-Simon scale– First test of intelligence, developed to identify children

who might have difficulty in school– Binet developed the concept of mental age in children

• Stanford-Binet scale– L. M. Terman’s adaptation of the Binet-Simon scale– Terman introduced the I.Q. score– A score of 100 is considered average

Aptitude and Achievement Tests

Aptitude tests are intended to predict your ability to learn a new skill and achievement tests are intended to reflect what you have

already learned.

Wechsler Tests

• Hard to use Formula to judge adults- 60 year old vs 30 year old. ….does not use the formula but uses the same scoring system.

• WAIS• WISC (preschool)

WAISWAIS measures overall intelligence and 11 other aspects related to intelligence that

are designed to assess clinical and educational problems.

Intelligence Tests

• Performance tests– Tests that minimize the use of language– Used to test very young children or people with

retardation– Also can be used to test those unfamiliar with English

• Culture-fair tests – Tests designed to reduce cultural bias– Minimize skills and values that vary from one culture to

another

Normal Distribution

The Flynn Effect

How do we construct an Intelligence Test?

• Standardized: the questions have been piloted on similar populations and the scores fall on a normal distribution.

• Reliable: Test-Retest, Split-halves Methods.

• Validity: Content, Predictive or Construct.

Types of Tests

Aptitude• Measure ability or

potential.

Achievement• Tests that measure

what you have learned.

Does Intelligence Change Over Time?

By age 3, a child’s IQ can predict adolescent IQ scores.Depends on the type of intelligence, crystallized or fluid.

Extremes of Intelligence

• Akrit Jaswal

Genetic and Environmental Influences on Intelligence

No other topic in psychology is so passionately followed as the one that asks

the question, “Is intelligence due to genetics or environment?”

Heredity vs. Environment:Which is More Important?

• There is general agreement that both heredity and environment affect IQ scores

• Debate centers around the relative contribution of nature (heredity) and nurture (environment) to the development of intelligence

• No other topic in psychology is so passionately followed as the one that asks the question, “Is intelligence due to genetics or environment?”

Genetic Influences

Studies of twins, family members, and adopted children together support the idea

that there is a significant genetic contribution to intelligence.

Correlation of IQ Scores of Family Members

Adoption Studies

Adopted children show a marginal correlation in verbal ability to their adopted

parents.

Brain Function

Studies of brain functions show that people who score high on intelligence tests perceive

stimuli faster, retrieve information from memory quicker, and show faster brain

response times.

People with higher intelligence respond correctly and quickly tothe above question.

Environmental Influences

Studies of twins and adopted children also show the following:

1. Fraternal twins raised together tend to show similarity in intelligence scores.

2. Identical twins raised apart show slightly less similarity in their intelligence scores.

Early Intervention Effects

Early neglect from caregivers leads children to develop a lack of personal control over the

environment, and it impoverishes their intelligence.

Romanian orphans with minimalhuman interaction are delayed in their development.

Schooling Effects

Schooling is an experience that pays dividends, which is reflected in intelligence scores. Increased schooling correlates with

higher intelligence scores.

To increase readiness for schoolwork,projects like Head Start facilitate leaning.

Group Differences in Intelligence Test Scores

Why do groups differ in intelligence? How can we make sense of these differences?

Ethnic Similarities and Differences

1. Racial groups differ in their average intelligence scores.

2. High-scoring people (and groups) are more likely to attain high levels of education and income.

To discuss this issue we begin with two disturbing but agreed upon facts:

Racial (Group) Differences

If we look at racial differences, white Americans score higher in average

intelligence than black Americans (Avery and others, 1994). European New

Zealanders score higher than native New Zealanders (Braden, 1994).

White-Americans Black-Americans

Average IQ = 100 Average IQ = 85

Hispanic Americans

Environmental Effects

Differences in intelligence among these groups are largely environmental, as if one environment is more fertile in developing

these abilities than another.

Reasons Why Environment Affects Intelligence

1. Races are remarkably alike genetically. 2. Race is a social category.3. Asian students outperform North American

students on math achievement and aptitude tests.

4. Today’s better prepared populations would outperform populations of the 1930s on intelligence tests.

5. White and black infants tend to score equally well on tests predicting future intelligence.

6. Different ethnic groups have experienced periods of remarkable achievement in different eras.

Gender Similarities and Differences

There are seven ways in which males and females differ in various abilities.

1. Girls are better spellers

2. Girls are verbally fluent and have large vocabularies

3. Girls are better at locating objects

4. Girls are more sensitive to touch, taste, and color

5. Boys outnumber girls in counts of underachievement

6. Boys outperform girls at math problem solving, but under perform at math computation

7. Women detect emotions more easily than men do

Principles of Test Construction

For a psychological test to be acceptable it must fulfill the following three criteria:

1. Standardization

2. Reliability3. Validity

Standardization

Standardizing a test involves administering the test to a representative sample of future test takers in order to establish a basis for

meaningful comparison.

Normal Curve

Standardized tests establish a normal distribution of scores on a tested

population in a bell-shaped pattern called the normal curve.

Reliability

A test is reliable when it yields consistent results. To establish reliability researchers

establish different procedures:

1. Split-half Reliability: Dividing the test into two equal halves and assessing how consistent the scores are.

2. Reliability using different tests: Using different forms of the test to measure consistency between them.

3. Test-Retest Reliability: Using the same test on two occasions to measure consistency.

Verbal Intell

ValidityReliability of a test does not ensure validity. Validity of a test refers to what the test is

supposed to measure or predict.1. Content Validity: Refers to the extent a test measures

your definition of the construct2. Criterion-related validity: Relationship between

scores on a test and an independent measure of what the test is supposed to measure1. Predictive Validity: Refers to the function of a test in

predicting a particular behavior or trait. For instance, we might theorize that a measure of math ability should be able to predict how well a person will do in an engineering-based profession.

2. Convergent Validity: we examine the degree to which the operationalization is similar to (converges on) other operationalizations we might correlate the scores on our test with scores on other tests that purport to measure basic math ability, where high correlations would be evidence of convergent validity.