Intelligence Testing

Intelligence Testing

A brief history of intelligence • The concept of 'intelligence' is relatively new, unknown a century ago, though it comes from older Latin roots • inter= between, within + legere =to bring together, gather, pick out, choose, catch up, catch with the eye, read; intellegere = to see into, perceive, understand • Francis Galton revived the term in the late 19th century, arguing for its innateness

A brief history of intelligence • Some objected to the innateness bias, and suggested the term be replaced with 'general scholastic ability' or 'general educational ability' • However, this did not catch on = most theorists today posit a construct of intelligence that is independent of education

Defining intelligence Binet (1916) defined it as the capacity to judge well, to reason well, and to comprehend well Terman (1916) defined it as the capacity to form concepts and grasp their significance Pintner (1921) defined it as the ability of an individual to adapt well to new situations in life Thorndike (1921) defined it as the power of good responses from the point of view of truth or fact Thurstone (1921) defined it as the capacity to inhibit instinctive response, imagine a different response, and realize the response modification into behavior

Defining intelligence Spearman (1923) defined it as a general ability involving mainly the ability to see relations and correlates Wechlser (1939) defined it as the global capacity of an individual to act purposefully, think rationally, and deal effectively with the environment Piaget (1972) defined it as referring to the superior forms of organization or equilibrium of cognitive structuring used for adaptation to the to the physical and social environment Sternberg (1985) defined it as the mental capacity to automatize information processing and to emit contextually appropriate behavior in response to novelty Gardner (1986) defined it as the ability to solve problems or fashion products valued within some setting.

Defining intelligence • You can take your pick of definitions but most agree that intelligence has to do with the related capacities of: i) Learning from experience ii) Adapting to ones environment • Think of a person lacking either of these, and you pick out people who seem to lack intelligence • Note however that very few formal tests of intelligence really demand subjects to do either of these!

Defining intelligence • Factor analystic studies (Sternberg, 1981) of informal views of an 'ideally intelligent' person capture these characteristics • They emphasize practical problem solving and social competence (the same thing?) as signs of intelligence, along with a factor loaded on verbal ability

Early History on the Intellectually Impaired-Era of Extermination • Prevailing attitude is one of extermination • Individuals with disabilities were seldom allowed to live since physical prowess was valued and essential for the survival of the group

Prehistoric Time • abandonment • murdered • failure to survive (hard life style)

Early Historic Time (1552 B.C.-300 A.D.) • very few records • first written reference found in Egyptian papyrus (Therapeutic Papyrus of Thebes) • persons with the most severe disabilities allowed to survive if able • many forced to beg for food and shelter • occurrence of a disability viewed as sickness and as a punishment from God for wrongdoing by the parent

Aristotle stated that humans differ from animals by intellect alone there was no concept of individual differences--and intellect was noted by man's ability to speak. • Therefore if an individual was unable to speak then s/he was no different than an animal.

Era of Ridicule • During this 1400 years most of the attitude of people concerning others with disabilities was that of ridicule or neglect. • Persons viewed with a mixture of fear and reverence.

Middle Ages (300-1350 A.D.) • Emphasis was on "other" world--little concern for anything but religion and one's own soul • All forms of deviance were seen in supernatural or superstitious terms • Mental illness and mental retardation seen as same condition

Renaissance (1350-1700 A.D.) • During this time attention shifted from "other world" to man, his nature, dignity, and senses • Spirit of curiosity gave birth to medicine and attempts to improve man's condition on earth • Differences in disabilities were noted but recognized only the severest disabilities

Era of Asylum • Lasted approximately 100 years • Concept of equality and the concept of humanism arose

Age of Reason (1700-1800 A.D.) • Humanism stressed dignity of person • Phrases were heard such as "all men are created equal" and "equality, brotherhood and liberty" • Individualism instead of Group stressed • Scientific approach was first used with problems relating to disabilities (e.g., MR)

1800's • Era of Education • Time when mass education became emphasis instead of education of the few • grew out of 1700's concern for enlightenment and individual worth • During the movement for training industrialization shifted man's work to machines; education became very important

Movement for Training (1800-1890) • Society became aware of the "slow learner" • Period of optimism-education seen as a "cure" • Significant people: • Louis Braille • Edouard Seguin • Guggenbuhl (1940's)

Era of Indictment • Late 1800's is period of disillusionment and pessimism • Recognize the fact that there is no "cure" for mental retardation • Research of time indicated that MR and other behavior disorders were prime factors in crime and degradation in country

1900's • time of Measurement (1890-1919 A.D.) • first mental test was devised (Cattell) • first special class was founded in the U.S. in Providence, RI in 1896 • first program to prepare special education teachers developed at NY University (1906) • Significant people: • Maria Montessori • Lewis Terman

Time of Social Control (1900-1930) • publication of 1912 research study of the Kallikak family by Goddard States • era overlapped the Era of Measurement and Social Control

History of Intelligence Testing • Head Circumference (Francis Galton 1880) – first attempts to measure intelligence • Binet-Simon (Alfred Binet 1909) – first “intelligence test” • comissioned by French gov to separate children into vocational vs academic schooling • did not design test to measure ‘intelligence’ • created concept of mental age (MA)

Psychological Measurement in the 19th Century • Interest in science and measurement • Emergence of psychology as an experimental and quantitative science • Interest in hereditary and neurological (“measurable”) basis of cognitive abilities (Galton)

History of Psychological Testing • Basis of psychological testing • The significance of individual differences • Why? • Interest in performance of professionals • Chinese system (2200 BC) • 19th century Europe

Psychological Measurement in the 20th Century • Public education and availability of limited funds • Needs of the military for allocating personnel (WW I)

The History of IQ testing • First IQ tests developed by Alfred Binet • Alfred Binet and Theodore Simon • 30 items of increasing difficulty - 1905 • Revision 1908 – age specific versions • These were developed to identify children who needed ‘special’ education • Binet believed that IQ could be increased by education

The History of IQ testing • Early IQ tests gave estimate of children’s MENTAL age by comparing their performance on various tasks with performance of children at various ages

The history of IQ testing • calculated as • IQ = Mental Age Chronological age x 100 Nowadays NORM referenced.. that is the average performance of a group is calculated, then individual comparison

Henry Herbert Goddard • Definition of Intelligence • "…our thesis is that the chief determiner of human conduct is a unitary mental process which we call intelligence: that this process is conditioned by a nervous mechanism which is inborn: that the degree of efficiency to be attained by that nervous mechanism and the consequent grade of intelligence or mental level for each individual is determined by the kind of chromosomes that come together with the union of the germ cells: That it is but little affected by any later influences except such serious accidents as may destroy part of the mechanism" (Goddard, 1920, p. 1).

Henry Herbert Goddard (1866-1957) • Major Contributions • Translated the Binet-Simon intelligence scale into English (1908) • Distributed 22,000 copies of the translated Binet scale and 88,000 answer blanks across the United States (1908-1915) • Established the first laboratory for the psychological study of mentally retarded persons (1910) • Helped to draft the first American law mandating special education (1911) • Strongly argued the hereditarian position

Henry Herbert Goddard

Stanford-Binet Intelligence Scale • Lewis Terman (1916-72) first U.S. intelligence test • Interested in gifted children • translated and modified Binet’s scale • Heavy reliance on vocabulary/language skills • incorporated old items from the Binet scale, plus some new items • poorly standardized on 1000 children and 400 adults who were not selected with care

Lewis Terman (1916-72) • Developed Intelligence Quotient IQ = (MA/CA)*100 MA= Mental Age; CA = Chronological Age

1916 Stanford-BinetSample Items for 12 yr olds Practical Problem Solving Vocabulary Grammar • Orange. • 45.Sportive. • 80.Exaltation. • 92. Theosophy • FOR THE STARTED AN WE COUNTRY EARLY AT HOUR • TO ASKED PAPER MY TEACHER CORRECT I MY • A DEFENDS DOG GOOD HIS BRAVELY MASTER Interpretation Similarities Memory • Snake, cow, sparrow • Book, teacher, newspaper • Wool, cotton, leather 3-1-8-7-9 6-9-4-8-2 5-2-9-6-1

A brief history of intelligence testing • The 1937 revision of the scale was improved: • It had wider range (more room on the floor floor and ceiling) • It had two parallel forms to permit re-testing • It was standardized on a carefully selected population, of 100 children in each six-month interval from 6 to 14 years, and 100 in each year from 15 to 18, with control of sex, selected from 17 different communities • Alas, they were all white and (therefore) above average SES • The test was re-normed in 1960 and 1972, and revised completely in 1986 (SB-IV)

IQ testing in the USA • In the USA strong supporters of IQ testing were scientists who believed that IQ is MAINLY genetic, and that society should breed a superior group of people • This is called eugenics

Army Alpha/Beta IQ Test (1917) – designed for WWI recruits • Assumed to be testing native intelligence • Assumed intelligence and literacy independent • Alpha for literates; Beta for illiterates and non-English speakers • Alpha subtests: Oral Directions; Arithmetic; Practical Judgment; Analogies; Disarranged Sentences; Number Series; Information • Beta subtests: Memory; Matching; Picture Completion; Geometric Construction

Army Alpha Results by Years of Education

Army Beta Results by Years of Education

S J Gould - A Nation of Morons • YERKES said that: • These tests measure • NATIVE INTELLECTUAL ABILITY • in other words intelligence which was unaffected by culture or educational opportunities

S J Gould - A Nation of Morons • Gould reports many problems in the administration of the tests • Illiterate men were allocated to the Alpha • The queues for the Beta became so long that some men were reallocated to the Alpha • Many who failed the Alpha were never recalled

S J Gould - A Nation of Morons • The BETA test still required men to use pencils and paper - and many had never been educated at all • Gould suggests that all the results should be viewed with scepticism

S J Gould - A Nation of Morons • However the results were used by the army and had great impact - mental testing became….. • ‘scientifically established’ • by 1921 commercial and educational establishments were using the tests

Test conclusions • The average mental age of white American adults stood at 13 … • It was possible to grade European immigrants by their country of origin. • People of Northern & Western Europe higher than the Slavs who were higher than people of southern Europe • Black people scored lowest of all • These ‘facts’ were used to provide a genetic explanation for the differences

S J Gould - A Nation of Morons • Carl Brigham (Yerkes colleague) • Explained the differences in terms of racial superiority • “we notice the Einsteins of the world BECAUSE they are exceptional for their Jewish race”

S J Gould - A Nation of Morons • Why is this not true? • Immigration from different parts of Europe took place at different times • The most recent immigrants scored worse on the written tests .. If native IQ was being measured ‘written English should have NO effect • Test scores rose with length of stay in the USA • Those who had been in the USA longer were more familiar with American customs & products

S J Gould - A Nation of Morons • Brigham • argued that it was a sign of intelligence to emigrate to the USA and that the brightest came sooner!! • Later immigrants were progressively more stupid

S J Gould - A Nation of Morons • Despite the evidence IQ tests took hold • 1924 US Congress passed the Immigration Restriction Act • The Act set quotas for immigration to the US based on figures 30 years earlier when immigration from Southern & Eastern Europe was low

Intelligence Testing