Tripken11 Intelligence Study Guide

Intelligence

INTRODUCTION: In 1917, as the United States mobilized its vast resources for the war against Germany, Professor Lewis Terman of Stanford University traveled east to meet with a group of prominent psychologists. Terman was an expert on intelligence testing, for he had pioneered the application of a French Intelligence test (developed by Alfred Binet) in the U.S. Terman, a devoted member of the Stanford University faculty, called his test the Stanford- Binet, and it was widely used in clinical settings.

But why was Terman meeting with other psychologists? Their goal: to develop some kind of psychological test that the U.S. Army could give to the thousands of new recruits coming into the army. The test would help them decide who had the intellectual potential to be an officer, who did not. Terman carried in his briefcase the rough materials his student Arthur Otis had designed for a questionnaire measure of intelligence. In several weeks the group of psychologists had designed the Army Alpha Examination, based on the Otis scales. The test was given to 1,700,000 men, and it seemed to work. Some were sent off to the trenches, and others were selected to lead them there. And psychologists, delighted with their success, began to spread their testing into civilian settings: particularly in educational settings.

School systems and colleges snatched up the tests for use in pupil classification, guidance, and admissions

Within 30 months of the first publication of the group test some four million children had been tested, and the IQ test was on its way to acceptance

I. Intelligence Testing

A. Historical Development

1)Alfred Binet Charged by the Minister of Public Instruction in Paris to develop a method of detecting "defective" children who could then be given special instructions

Although he toyed with the idea of developing a physiological measure, he ended up with a test he called "aptitude for academic achievement"

this test was designed to be relevant in academic settings

Simple procedures used identified behaviors for each age (important - this test was age specific - also known as the "age-standard method"). This made it possible to establish range of normality ("norms"), then checked to see if the child/person possessed these abilities

a) 3 years: show eyes, nose, mouth, name objects in a picture, repeat figures, repeat a sentence of 6 syllables, give last name

b) 5 years: compare 2 boxes of different weights, copy a square, repeat a sentence of 10 syllables, put together 2 pieces of a game

c) 7 years: indicate omissions in drawings, copy a written sentence, copy a triangle and a diamond, etc.

d) 9 years: give the date complete, name days of the week, give definitions, memory

this measure proved highly successful in predicting school success

2) In 1916, an American psychologist (TERMAN) revised and translated the test

a) problem: unfair to say an 8 year old is more intelligent than a 6 year old simply because he or she gets more questions right

b) need to adjust for chronological age

c) He used the formula IQ = MA/CA X 100 (to get rid of decimals) - HOWEVER, this formula was actually developed by William Stern in 1912 in order to avoid the inconvenience of decimals.

For example - A 10 year old with a mental age of 8 has a ratio of 8/10 = .8 and a 6 year old with a mental age of 4 has a ratio of 4/6 = .67. This indicates that the 6 year old is relatively farther behind his or her age peers.

STERN then got rid of the decimal point so .8 becomes 80, and .67 becomes 67. d. if 100, just right. This would mean that a person has the same mental age and chronological age.

B. Types of Tests

1) Individual Tests

a) Stanford-Binet: This made it possible to test adults & children

1. established the procedures to use in administering the test - takes 1 hour or more so it was not good for collecting data from groups very quickly. This was not good if you wanted to test military troops - So, Otis instead created an oral intelligence test (goes back to introduction).

2. established the norms for the test (e.g., how many an "X" year old got correct) But, there is still a problem here. This test still utilized the intelligence quotient developed by Stern - but mental age slows dramatically after childhood. So, someone could go from gifted as a young person, to mentally challenged as an older adult without actually getting "less intelligent".

Example: a 15 year old female with a mental age of 20: 20/15 x 100 = 133, which would classify her as "gifted". Then, as an adult of age 40, let's say she retained the mental age of 20: 20/40 x 100 = 50. Now she would be classified as mentally retarded, yet she may be successful doctor. This problem was overcome by the introduction of the DEVIATIONIQ, by Wechsler.

3. Wechsler tests

This scale compares a person's intelligence test scores with those of the mean scores of their age peers. Those who perform exactly the same as their age peers would receive the score of 100.

a) developed many tests, three very important: WISC (W Int. Scale for Children), the WAIS (W. adult int. scale), and the WPPSI (W preschool and primary scale of intelligence; good for ages 4-6 1/2)

b) attempted to bring in more behavioral measures rather than just verbal

c) two subsections: verbal subtests, performance subtests - verbal: information, comprehension, arithmetic, digit span, similarities, and vocabulary -performance: picture arrangement, picture completion, block design, etc.

C. Forms of Intelligence

1)Basic approach: verbal and math

2) Sternberg's Triarchic theory of intelligence

Sternberg performed poorly on IQ tests as a child and suffered from severe test anxiety. Yet he was able to become a successful cognitive psychologist and a leader in the field of intelligence. This was a major influence in his belief that intelligence was much more than those abilities measured by traditional intelligence tests. He and colleagues wanted to know what the "lay person" though intelligence was so they interviewed many people. Most people indicated that intelligent people have good verbal skills, problem-solving skills, and social judgment.

Thus, he developed the Triarchic theory which is comprised of the following:

a) componential intelligence - reflects our information-processing abilities. This is similar to traditional intelligence tests.

b) experiential intelligence - ability to combine different experiences in insightful ways to solve novel problems. Reflects creativity.

c) contextual intelligence - ability to function in practical, everyday social situations. Reflects "street smarts".

Sternberg recognized that situations may call for one type or a combination of all three, and that each can be improved through training. D. IQ Controversies

3) Questions to consider

a) What does the IQ Test Measure? Intelligence?

e.g., the California Legislature has twice voted to prohibit group testing in schools on the grounds their effect is to limit the quality of education given to minority students. Many experts have gone on record as opposing IQ tests as invalid, easily altered by special coaching, and monopolizing the testing industry.

Intelligence ----> IQ score Intelligence + Other Factors -----> IQ score

b) Are IQ tests Valid (fair)? -why is there a difference between groups on the IQ test?

c) Is Intelligence Genetically determined Nurture Nature -learning -instinct -experience -innate determinant -flexible -inflexible, wired in -acquired -genetic

Intelligence: mental quality consisting of the ability to learn from experience, solve problems, and use knowledge to adapt to new situations.

Intelligence Test: a method for assessing an individual's mental aptitudes and comparing them with those of others, using numerical scores.

Factor Analysis: a statistical procedure that identifies clusters of related items (called factors) on a test; used to identify different dimensions of performance that underlie one's total score.

Reification: When we view an abstract concept (like intelligence) as if it were a concrete thing, we have made the error of reification.

Distribution of IQ Scores

Theories of Intelligence
Francis Galton (late 1800's): He believed that some people were more superior than others with respect to intelligence. He felt those people should be encouraged to mate and that less superior people should not be allowed to produce offspring (eugenics movement). He felt you could determine one's intelligence by measuring his/her head size, body proportions, and reaction time.
Charles Spearman (1930's): Noted that people "smart" in one area were often skilled in other areas. Thus, he believed in an underlying general intelligence or g-factor.
g-factor: a general intelligence factor that Spearman and others believed underlies specific mental abilities and is therefore measured by every task on an intelligence test.

L.L. Thurstaone (1930's): Disagreed with Spearman. He identified "8 Primary Mental Abilities" and believed they were all independent from each other. They included: perceptual speed, numerical ability, verbal meaning, memory, spatial skills, reasoning, word fluency, & comprehension. The existence of Savant Syndrome supports his viewpoint.
Savant Syndrome: a condition in which a person otherwise limited in mental ability has an exceptional specific skill, such as in computation or music. Howard Gardner (1980--): agreed with Thurstone in that intellectual skills were independent of one another. He identified 8 independent multiple intelligences: logical/mathematical, spatial, linguistic, body-kinesthetic, musical, intrapersonal, interpersonal, & naturalist.

Robert Sternberg (1980--): believed there are 3 general types of IQ. He called this the Triarchic Theory of Intelligence.
Academic (or analytic): intelligence which is assessed by intelligence tests, which present well-defined problems with a single correct answer (i.e., school smarts).
Creative: intelligence demonstrated by reacting adaptively to new situations and generating novel ideas.
Practical: intelligence required for everyday tasks, which are frequently ill-defined with multiple solutions (i.e., street or business smarts).

Other Types of Intelligence
Emotional Intelligence: the ability to perceive, express, understand, and regulate emotions.

Creativity: the ability to produce novel and valuable ideas.

Brain Functions and Intelligence
While Galton was incorrect and you cannot determine IQ from head size, there is a moderate correlation (+.44) between brain volume and IQ (i.e., more cortical tissue and 17% more synapses in educated versus less educated people). Also, we find moderate correlations between IQ and (1) processing speed; (2) perceptual speed and; (3) neurological speed.

ASSESSING INTELLIGENCE
Aptitude Test: a test designed to predict a person's future performance. Aptitude refers to the capacity to learn (IQ tests are considered to be aptitude tests).

Achievement Test: a test designed to assess what a person has already learned (e.g., AP exams, driver's license test).
**While the SAT is designed to predict future performance (and is thus an aptitude test), it is clearly also an achievement test.

Alfred Binet: Along with Theodore Simon developed the first intelligence test in France in 1904. It was designed to measure a child's mental age in order to predict future school performance. The test was called the Simon-Binet Intelligence Test. It was later revised at Stanford University by Lewis Terman and is now known today as the Stanford-Binet.

Intelligence Quotient (IQ): defined originally (Stern) as the ratio of mental age (MA) to chronological age (CA) multiplied by 100 (thus, IQ = MA/CA * 100). On contemporary intelligence tests, the average performance for a given age is assigned a score of 100.

Wechsler Adult Intelligence Scale (WAIS) & Wechsler Intelligence Scale for Children (WISC):These are the 2 most frequently used IQ tests in the US. They provide a verbal IQ along with a non-verbal or performance IQ. They also provide an overall or full-scale IQ score. The Wechsler tests have a mean of 100 and a standard deviation of 15.

Principles of Test Construction

Standardization: defining meaningful scores by comparison with the performance of a pretested "standardization group".
Normal Curve: the symmetrical bell-shaped curve that describes the distribution of many physical and psychological traits (including intelligence). Most scores fall near the average, and fewer and fewer scores lie near the extremes.
Reliability: the extent to which a test yields consistent results, as assessed by the consistency of scores on two halves of the test (split-half reliability) or on retesting at a later date (test-retest reliability).
Validity: the extent to which a test measures or predicts what it is supposed to.
a) Face Validity: the extent to which questions on a test appear to measure the construct of interest.
b) Content Validity: extent to which a test actually measures the construct of interest.
c) Predictive Validity: the success with which a test predicts the behavior it is designed to predict.

This is assessed by computing the correlation between test scores and the criterion behavior (also called criterion-related validity).

Criterion: the behavior (such as college grades) that a test (such as the SAT) is designed to predict.

Extremes of Intelligence
Mental Retardation: a condition of limited mental ability, indicated by an IQ score below 70 and difficulty in adapting to the demands of life; varies from mild to profound.

Down Syndrome: a condition of retardation and associated physical disorders caused by an extra chromosome in one's genetic makeup.

GENETICS & ENVIRONMENT
Heritability: the proportion of variation among individuals on a particular trait that can attributed to the differences in their genes.
IQ and Genetics

Twin & adoption studies show that genetics do play a role in intelligence (e.g., IQ's of identical twins correlate at about .85, while fraternal twins at about .60).

However, the same studies show how important environment is in that identical twins reared together correlate at .85, while those raised in different homes correlate at .71.

Most psychologist agree that differences in group IQ scores based on ethnic background or gender are due to environmental differences not genetics.

Brief information about the Wechsler Adult Intelligence Scale

David Wechsler designed intelligence tests made up of items that are appropriate for a wide range of ages.
There are three main types of Wechsler intelligence tests:
Wechsler Pre-school and Primary Scale of Intelligence (WPPSI) - 3-7 years
Wechsler Intelligence scale for Children (WISC) - 7-16 years
Wechsler Adult Intelligence Scale (WAIS) - 16 years and over
The first was the Wechsler-Bellevue Intelligence Scale (Wechsler, 1939).
Replaced 1955 by the Wechsler Adult Intelligence Scale (WAIS).
1981 revision is referred to as the WAIS-R.
A subsequent revision was conducted in the US in 1997 and the present scale is the 3rd edition, known as the WAIS-III. The revised version has almost 80 per cent of the original form. A number of improvements have been made including an attempt to make it more culturally fair.
The WAIS(R) was standardised on a sample of 1,800 U.S. subjects, ranging from 16 to 74 years of age. It was a highly stratified sample, broken down into 9 different age groups. Equal numbers of men and women were used, as were white and nonwhite subjects, in line with census figures. It was further broken down into four geographic U.S. regions and six occupational categories. There was also an attempt to balance urban and rural subjects. The mean I.Q. for each age group on this test is 100, with a standard deviation of 15. The WAIS scales have impressive reliability and validity.
There are different adaptations of the scale by country. For example, in Australia we have the Australian adaptation of the WAIS-R (1989).
11 separate subtests, which are broken into the Verbal scale (6 subtests) and the Performance scale (5 subtests).
A person taking the test receives a full-scale IQ score, a verbal IQ score, a performance IQ score, as well as scaled scores on each of the subtests.

WAIS Scales

Verbal WAIS scales

1. Information: 29 questions - a measure of general knowledge.

2. Digit Span: Subjects are given sets of digits to repeat initially forwards then backwards. This is a test of immediate auditory recall and freedom from distraction.

3. Vocabulary: Define 35 words. A measure of expressive word knowledge. It correlates very highly with Full Scale IQ

4. Arithmetic: 14 mental arithmetic brief story type problems. tests distractibility as well as numerical reasoning.

5. Comprehension: 16 questions which focus on issues of social awareness.

6. Similarities: A measure of concept formation. Subjects are asked to say how two seemingly dissimilar items might in fact be similar.

Performance WAIS scales

7. Picture Completion: 20 small pictures that all have one vital detail missing. A test of attention to fine detail.

8. Picture Arrangement: 10 sets of small pictures, where the subject is required to arrange them into a logical sequence.

9. Block Design: Involves putting sets of blocks together to match patterns
on cards.

10. Digit Symbol: Involves copying a coding pattern.

11. Object Assembly: Four small jig-saw type puzzles.

Interpretation of the WAIS (R)

Three IQ scores are obtained from the WAIS(R):
1. Verbal IQ
2. Performance IQ
3. Full Scale IQ

1. Francis Galton: The 1st Modern Attempt (late 1800s)

Intelligence tests are grounded in the work of Francis Galton in the late 19th century. Galton is considered to be the father of the study of individual differences [and, incidentally was the half-cousin of Charles Darwin]. For Galton, measurement of intelligence was to be as direct as possible a measure of underlying intelligence. Hence, Galton suggested reaction time as a feasible approach and pursued various sensori-motor measurements.
Interestingly, more contemporary "Galton-like" approaches are being pursued by psychologists such as Arthur Jensen and Mike Andersen who assert that they are assessing the integrity of the central nervous system - inherent capabilities (Intelligence A) - as opposed to manifestations of intelligence in everyday life (Intelligence B). (Weinberg, 1989).

2. Alfred Binet: The origins of IQ Testing (early 1900’s)

Alfred Binet is celebrated in history as the man who created the first 'intelligence test' in the form as we know them today. He is commonly known as the “father” of IQ testing.
In 1904, Binet was commissioned by the French Ministry of Public Instruction to develop techniques for identifying primary grade children whose lack of success in normal classrooms suggested the need for some form of special education (Gould, 1981).
In 1905 he produced the Binet-Simon scale [with Theodore Simon] - the first intelligence test. Binet took a pragmatic approach, choosing a series of 30 short tasks related to everyday problems of life (e.g.
attend to simple instructions