Testing and Individual Differences

Key Ideas:1. Theories of intelligence

Charles Spearman

• The G Factor• Major Contributions• “First systematic psychometrician” and father of classical

test theory (Jensen, 1994)• Pioneer of the statistical technique called factor analysis• Discovered a general factor (g) in correlations among

mental tests (positive correlations)• G factor could be expressed as a single number such as

an IQ score

Raymond Catell

• Major Contributions• The Cattel Horn Theory of Fluid and Crystallized

Intelligence.• Application of advanced statistical techniques to

the study of intelligence• Spearman’s concept of general intelligence could

be broken down into two relatively independent components. Fluid and Crystallized intelligence

Fluid Intelligence

• Fluid Intelligence• Characteristics:– Believed it was innate/independent of education and

experience– Memory, speed of information processing, and

reasoning abilities– Forming new concepts, seeing underlying

relationships and quickly solving unfamiliar problems.– Like other biological capacities it declines with age

Crystallized Intelligence

• Refers to stored knowledge and and skills gained through experience and education

• Remains stable or increases with age.

Robert Sternberg

• Definition of Intelligence• "I define [intelligence] as your skill in achieving

whatever it is you want to attain in your life within your sociocultural context by capitalizing on your strengths and compensating for, or correcting, your weaknesses

• Major Contributions• Triarchic Theory of Human Intelligence • Several influential theories related to creativity,

wisdom, thinking styles, love and hate

Triarchic Theory

• Three Aspects of Intelligence• Analytical Intelligence: logical reasoning skills

that include analysis, evaluation and comparison

• Creative Intelligence: imaginative skills/seeing new relationships/ creating something different

• Practical Intelligence: street smart skills dealing and coping with people and events

Howard Gardner: Multiple Intelligences

• Howard Gardner's Theory of Multiple Intelligences (1983) proposes that intelligent behavior does not arise from a single unitary quality of the mind, as the g based theories but rather that different kinds of intelligence

• Partially cultural based.

Multiple Intelligences• The seven intelligences proposed by Gardner are linguistic, logical-

mathematical, spatial, bodily-kinesthetic, musical, interpersonal and intrapersonal.

• Linguistic intelligence enables individuals to read, write and speak well. • Logical-mathematical intelligence encompasses logical thinking (as

might be used in chess or deductive reasoning, for example) as well as mathematical and scientific problem-solving.

• Spatial intelligence makes its appearance when an individual navigates an unfamiliar set of streets, or when an architect visualizes her plans for a building.

• Musical intelligence generates the set of skills that allow musicians to play a tune by ear, or to execute a phrase with sensitivity and grace.

Multiple Intelligences• Bodily-kinesthetic intelligence is necessary for problem-solving that

requires the individual to use his or her physical body, as would be necessary for performing a complex surgical procedure, executing a series of dance steps or catching a fly ball.

• Interpersonal intelligence drives social skills and things like empathy and intuition about what motivates other people-a type of understanding that is necessary for salespersons, teachers and clergy, for example.

• Intrapersonal intelligence involves a similar set of abilities, but these are turned toward the self; individuals who have high intrapersonal intelligence have an accurate self-understanding, and can use this to their advantage in problem-solving.

• Gardner asserts that logical-mathematical and linguistic intelligences are overemphasized in traditional models of human intelligence, but that this is a cultural artifact; in different life circumstances, different intelligences would gain higher priority ( Gardner, 1993

The Development of Intelligence Tests

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?

Problems with the IQ Formula

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

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

If a 56 year old man

does as well as an average 27 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

• Statistically fixed mean at a 100• Today the Stanford Binet and most other intelligence exams use this scale

The Flynn EffectFlynn Effect

How do we construct Intelligence tests?

Tests must be:

• Standardized• Reliable• Valid

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.

• Construct are ideas that help summarize a group of related phenomena or objects

Standardization• The test must be pre-tested to a large

representative sample of people and• Form a normal distribution or bell curve

The scores of the representative sample set the norms or standards against which the performance of other test takers can be evaluated.

Reliability• The extent which a test yields

consistent results over time.• Spilt halves or test–retest

method.• The extent which a test yields

consistent results over time.• Spilt halves: split the

questions evenly(odd/even) need a positive correlation between the two test scores

• test–retest (compare results of two separate administrations of the same exam)method.

ValidityThe extent to which a test measures

what it is supposed to measure.• Content Validity: does the test

sample a behavior of interest

• Predictive Validity: does the test predict future behavior.

Criterion related validity is the key measure of test validity

Types of Tests

• Aptitude Tests: predict future performance: SAT• Achievement Tests: assess what a person has

already learned AP Psychology Exam• Performance tests: include SATs, AP tests,

Intelligence Tests• Observational Tests: job interviews/formal on

the jog observations• Self Report Tests:MMPI-2

Ethics and Standards In Testing

• Bias on Tests• African Americans and other minorities have

tended to score lower on average than European American on intelligence Tests

• Culturally biased

Extremes of Intelligence

• Mental retardation/Cognitively Disabled• Below 70 on an IQ Test/difficulty adapting in

everyday life.• Between 50-70: (85%)sixth grade level/care for

themselves, hold a job, get married/main streamed in school

• Between 35 and 49: (10%) second grade level training in basic living skills/group home living

• Savants

Heredity/Environment and Intelligence

• Nature: Genetic Defects->down syndrome• Nurture: Fetal Alcohol Syndrome prenatal

exposure• Interaction of Nature and Nurture:

PKU/Phenylketonuria• 75% of mental retardation results from

nurture called cultural-familial retardation• Head Start program: first two grades

Studies of twins

• Identical Twins reared together and reared apart• Adopted identical twins more like their biological

parents and get even more similar with age.• Brain scans of identical twins reveal similar brain

volume and anatomy• Fraternal twins do not share the exact same

genetic makeup. Their Intelligences are no more likely to be similar than other siblings in the same family.

Environmental Influences on IQ

• During childhood , siblings raised together are more similar in IQ than those raised apart

• IQ is raised by school attendance• Children from deprived environments who

were moved into middle and upper class fosters homes or adoptive homes tend to see an increase in IQ scores

Heritability

• The proportion of variation among individuals in a population that results from genetic causes.

• 50 to 75%

Factor Analysisloyal, devoted, rebellious, affectionate, distant, cold, aloof, aspiring, ambitious, motivated, unmotivated, candid, guarded, secretive, caring, callous, cheerful, gloomy, grumpy, considerate, thoughtful, inconsiderate, helpful, combative, courageous, fearful, courteous, rude, impolite, decisive, uncommitted, uncaring, hostile, determined, indecisive, unsure, perseveres, endures, relents, enthusiastic, apathetic, indifferent, expansive, constricting, flexible, inflexible, rigid, unbending, stubborn, forgiving, unforgiving, resentful, spiteful, focused, unfocused, scattered, authoritarian, controlling, friendly, unfriendly, distant, aloof, hostile, frugal, thrifty, wasteful, generous, stingy, miserly, selfish, malicious, hateful, grateful, ungrateful, unappreciative, hard-working, lazy, honest, dishonest, deceiving, humble, arrogant, conceited, interested, indifferent, complacent, jealous, envious, covetous, cruel, mean, mature, immature, modest, vain, open-minded, tolerant, small-minded, intolerant, optimistic, persistent, practical, impractical, punctual, realistic, naïve,¯

WAIS (Weschler Adult Intelligence Scale)

• most widely used intelligence test• gives separate verbal and performance scores• used to identify learning disabilities• A learning disability is possible if either:

- a child scores much higher on one section that the other - a child has a much higher aptitude score than achievement score.

• WISC (Wechsler Intelligence Scale for Children) – modified version of WAIS for children

Sample WAIS Verbal tasks:

Most standardized tests result in a normal distribution (bell-shaped).

In a normally distributed population, 68% of people fall within 1 standard deviation of the mean, 95% of people fall within 2 standard deviations of the mean, and 99.7% of people fall within 3 standard deviations of the mean.Reminder: The standard deviation is the square root of the variance.