I. What is intelligence? II. How is it tested? III. Controversies

Part I: Intelligence

Intelligence Intelligence should be universal Exactly how intelligence is expressed will differ given the context.

History of Intelligence Testing

History of Intelligence Testing (1600s) Francis Bacon - the scientific method

History of Intelligence Testing (1600s) Francis Bacon - the scientific method (1800s) Francis March “vulgar utilitarianism”

History of Intelligence Testing (1600s) Francis Bacon - the scientific method (1800s) Francis March “vulgar utilitarianism” Francis March sat beside James Cattell

History of Intelligence Testing James Cattell gets stoned, and then argues

History of Intelligence Testing James Cattell gets stoned, and then argues Cattell becomes a psychometrician

History of Intelligence Testing James Cattell gets stoned, and then argues Cattell becomes a psychometrician At Cambridge falls in with Francis Galton

History of Intelligence Testing James Cattell gets stoned, and then argues Cattell becomes a psychometrician At Cambridge falls in with Francis Galton Francis Galton would later develop eugenics

History of Intelligence Testing James Cattell gets stoned, and then argues Cattell becomes a psychometrician At Cambridge falls in with Francis Galton Francis Galton would later develop eugenics 1889 - Cattell is now a professor at age 29

History of Intelligence Testing Cattell coined ‘mental tests’ For example, Bisection of a 50 cm line Judgment of a 10 second time Number of letters repeated

History of Intelligence Testing 1895 Cattell moves to Columbia U (NY)

History of Intelligence Testing 1895 Cattell moves to Columbia U (NY) As president of the APA Cattell convenes a meeting

History of Intelligence Testing 1895 Cattell moves to Columbia U (NY) As president of the APA Cattell convenes a meeting recommends they test senses, motor capacity, and mental processes

History of Intelligence Testing 1895 Cattell moves to Columbia U (NY) As president of the APA Cattell convenes a meeting recommends they test senses, motor capacity, and mental processes Back in France Binet emerges on the scene

History of Intelligence Testing Spearman gives birth to the g/s factor theory

History of Intelligence Testing Henry Goddard emerges, and in 1908 visits Binet

History of Intelligence Testing Binet’s ideas of testing move away from labels

History of Intelligence Testing Binet’s ideas of testing move away from labels IQ = (Mental age/chronological age) *100 For example, (15/10) * 100 = 150

History of Intelligence Testing Binet’s ideas of testing move away from labels IQ = (Mental age/chronological age) *100 For example, (15/10) * 100 = 150 Ellis Island under Goddard WWI recruits under Yerkes & Terman

History of Intelligence Testing 1920s -remember Cattell studied with Darwin’s cousin Galton

History of Intelligence Testing 1920s -remember Cattell studied with Darwin’s cousin Galton Terman argued that the correlation between test scores and social status pointed to heredity of intelligence

History of Intelligence Testing 1920s -remember Cattell studied with Darwin’s cousin Galton Terman argued that the correlation between test scores and social status pointed to heredity of intelligence Terman would work with Thorndike Dewey argues that these tests measure a social construction

History Leads to Theory Thurstone’s work would lead to the recognition that there are 7-9 mental abilities

History Leads to Theory Horn, student of Cattell, brings together work in the field and devises the Cattell-Horn Theory

History Leads to Theory Horn, student of Cattell, brings together work in the field and devises the Cattell-Horn Theory Modern theory rests on the idea that intelligence can be found by analyzing inter-correlations of scores on mental ability tests

History Leads to Theory Meanwhile distinct factor analytic work by Carroll has led to

CARROLL’S (1993) THREE-STRATUM THEORY OF COGNITIVE ABILITIES General Intelligence (Stratum III) General (Carroll, 1993, 1997) Gf Gc Gy Gv Gu Gr Gs Gt (Stratum II) Broad Processing Speed (RT Decision Speed) General Memory & Learning Broad Visual Perception Broad Auditory Perception Broad Retrieval Ability Broad Cognitive Speediness Fluid Intelligence Crystallized Intelligence (Stratum I) Narrow 69+ narrow abilities found in data sets analyzed by Carroll © Institute for Applied Psychometrics, llc K McGrew 10-26-04

Intelligence Theory Meets Practice 1985 Richard Woodcock hears about the theory 1989 The Great Gathering This leads to factor analytic studies of the WJ

Gardner’s Multiple Intelligences Linguistic Logical-mathematical Spatial Musical Bodily-Kinesthetic Interpersonal Intrapersonal Naturalist

Part II: Testing Intelligence

Individual Tests of Intelligence Stanford-Binet Wechsler Scales Kaufman Scales Woodcock Johnson

Wechsler Scales Wechsler Adult Intelligence Scale WAIS, WAIS-R, WAIS-III Wechsler Intelligence Scale for Children WISC, WISC-R, WISC-III, WISC-IV Wechsler Preschool and Primary Scale of Intelligence (WPPSI)

Subscales of the WISC-III Verbal Information Similarities Arithmetic Vocabulary Comprehension Digit Span Performance Picture Completion Picture Arrangement Symbol Search Object Assembly Coding Mazes

Part III: Controversies

Testing Issues Inadequate sample of each domain Limited (nonspecific) treatment or instruction implications

Thurstone Binet Terman Yerkes Horn Wechsler Cattell Gardner

Bell Curve Assertions IQ tests are not biased against minority groups. A significant fraction of the individual differences in IQ scores is explained by genetics (40-60%). African-Americans score significantly lower than White-Americans on IQ tests (12-15 points).

Gould Debunks the Bell Curve “The authors omit facts, misuse statistical methods, and seem unwilling to admit the consequences of their own words.” “Nothing . . . angered me more than the authors’ failure to supply any justification for their central claim . . . that the number known as g . . . captures a real property in the head.”

Bigger Questions Are intelligence tests useful? If so, for what? If not, why not? Are intelligence tests biased? What are the positive and negative social consequences of using intelligence tests? What are the alternatives?

APA Consensus Statement It is widely agreed that standardized tests do not sample all forms of intelligence. Environmental factors contribute substantially to the development of intelligence, but it is not clearly understood what those factors are or how they work.

The Flynn Effect Across 14 nations, 5-25 point increase in IQ within one generation 90% of those born 100 years ago would score at the 5th percentile of current norms Are we really getting smarter?