Psychological Testing and Individual Differences pt. 1

What makes us smart?Or not so smart?

Table of Contents:

• Standardization and Norms• Reliability and validity• Types of Tests• Ethics and standards in testing• Intelligence• Intelligence testing• Kinds of intelligence• Heredity/environment and intelligence• Human diversity

Standardization and Norms

• Psychometrics: measurement of mental traits, abilities, and processes.

• Psychometricians are involved in test development in order to measure some construct or behavior that distinguishes people.

• Constructs are ideas that help summarize a group of related objects.– For example, we can’t measure happiness, honesty or

intelligence in feet or meters. Even though we cannot observe happiness they are a useful concept for understating, describing, predicting and influencing behavior.

How do we construct an Intelligence Test?

Standardization and Norms

• Standardization: is a two part test development procedure that first establishes test norms from the test results of the large sample.

• Norms are scores established from the test. For example the means core for the SAT is 500.– When administering a standardized test, all

proctors must give same directions and conditions and scores sheets.

Reliability and validity

• Reliability refers to when you can obtain the same score no matter where, when or home many times we take it.

• ***The closer the correlation coefficient is to 1.0 the more reliable the test.

Test-Retest: Give test to a large group, then give exactly the same test to same group laterSplit-Half: Making sure scores on one-half of a test match the scores on the other half

Reliability and validity• Valid: it is accurate, the test accurately measures or

predicts what it is suppose to.– Face Validity: measure of the extent to which the content of the

test measures all of the skills. For example, AP exam is suppose to ask between 5 and 7 questions dealing with testing.

– Content Validity: measure extent of the knowledge– Criterion related validity: measures extent to which a tests results

correlate with other accepted measure– Predictive Validity: forecasts a specific future result. For example.

The SAT is designed to predict how well someone will succeed in their freshman year in college.

– Construct Validity: measures behavior. For example the MMPI.

Types of Tests

• Psychological tests can be sorted into 3 categories of:

• Performance Tests,• Observational

Tests, • Self-report Tests

Types of Tests

• Performance Tests: SAT’s , AP, Wechsler intelligence test, Stanford-Binet intelligence, classroom tests, finals, driver’s license

• Observational Tests: person being tested does not have a single well defined task but assessed on typical behavior.: Employment interviews, on the job observations.

• Self-Report Tests require the test taker to describe his or her feelings, attitudes, beliefs, values, opinions, physical state: MMPI

Another Type of Tests can be categorized into ability, interest, and personality tests relevant to decision

making:

• Aptitude:• Measure ability

or potential.

Achievement:Tests that measure what you have learned.

Ethics and Standards in Testing

• Because some groups (such as African Americans) have tended to score lower on average than other groups (such as European Americans) on intelligence tests and SATS, critics argue that tests are bias. Not biases with respect to predictive validity but biased with respect to performance differences from cultural experience.

• Culture relevant tests incorporate skills and knowledge related to the cultural experiences of the test takers. Ex. Questions about boll weevil

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.

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. 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.

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?

Problems with the IQ Formula

• It does not really work well on adults, why?

then his IQ would be 50!!!!!!

If a 60 year old man

does as well as an average 35 year old

That makes no sense!!!!!

Wechsler Tests

• More common way to give IQ tests….does not use the formula but uses the same scoring system.

• WAIS• WISC• WPPSI

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.

Psychological Testing and Individual Differences pt. 2

Intelligence

What makes us smart?Or not so smart?

Intelligence and Intelligence Testing• Intelligence: aggregate or global capacity of the

individual to act purposefully, to think rationally, and to deal effectively with his environment.

Intelligence and Intelligence Testing

• Alfred Binet and Simon were hired by the French government to identify children who would not benefit from a traditional school setting and those who would benefit from special education. It was only meant to be used for class placement.

Intelligence and Intelligence Testing

• Binet thought that as we age, we become more sophisticated in the ways we know about the world and so 6 year old would answer questions differently than 8 year olds.

• As a result children were assigned a Mental age (what a person of a particular age should know).

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

Terman and his IQ Test'Stanford-Binet Intelligence Scale' • 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?

Wechsler Tests

• David Wechsler developed another set of age-based intelligence tests. More common way to give IQ tests….does not use the formula but uses the same scoring system.

• More helpful for determining the extremes of intelligence.

Mental Retardation vs. Genius• Mental Retardation: When test takes fall below the

mean score of 70 on IQ test. Weshsler test. WAIS

Normal Distribution

Genius: when above 130

Charles Spearman and his G factor• John Horn and Taymond Cattell determined

that Spearman’s g should be divided into two factors of intelligences:

• Fluid Intelligence: cognitive abilities requiring speed or rapid learning that tend to diminish with adult aging

• Crystallized intelligence: learned knowledge and skills such as vocabulary that tend it increase with age.

Howard Gardner and Multiple Intelligences

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

• Gardner believed that there exists at least 8 different types of intelligences

Gardner’s Theory of Multiple Intelligence

Robert Sternberg and his Triarchic Theory

• Most commonly accepted theory today.• Three types of intelligence1. Analytical what is tested by IQ test,

what we are asked to do in school2. Creative: adaptive reaction to novel

situations, showing insight, and being able to see more than one way to solve a problem.

3. Practical: “street smarts” ability to read people, knowing how to put together a bake sale

Creativity

• Creativity: ability to generate ideas and solutions that are original, novel, and useful. Not usually measured by intelligence tests.

• Threshold Theory: a certain level of intelligence is necessary but not sufficient for creative work.

Heredity/Environment and Intelligence

• Nature/Nurture controversy: what extent is intelligence hereditary and what is learned.

• Nature:– Down’s Syndrome

Nurture:Fetal Alcohol Syndrome (environmental)

Heredity/Environment and Intelligence

• Studies of Twins:• Identical twins have similar scores on intelligence tests.

Intelligence scores of adoptees are more like those of their biological parents than their adopted parents. Brain scans of twins reveal similar brain volume and anatomy.

Heredity/Environment and Intelligence• Environmental Influences on Intelligence::• Siblings raised together are more similar in IQ than

siblings raised apart.• Children from deprived homes then moved into

middle/upper class foster homes tend to increase iq. School attendance results in increased IQ scores. In fact, scores tend to steadily increase. James Flynn observed that we start doing better on tests called the FLYNN EFFECT

Heredity/Environment and Intelligence

• Heritability:• Results from genetic causes. Hereditability for

intelligence estimates range 50 to 75%• Reaction Range Model: genetic makeup determines

the upper limit for an individual’s IQ.