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

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


• (1600s) Francis Bacon - the scientific method



• (1800s) Francis March “vulgar utilitarianism”



• (1800s) Francis March “vulgar utilitarianism”

• Francis March sat beside James Cattell


• James Cattell gets stoned, and then argues



• Cattell becomes a psychometrician




• At Cambridge falls in with Francis Galton





• Francis Galton would later develop eugenics





• Francis Galton would later develop eugenics

• 1889 - Cattell is now a professor at age 29


• Cattell coined ‘mental tests’• For example,

– Bisection of a 50 cm line– Judgment of a 10 second time– Number of letters repeated


• 1895 Cattell moves to Columbia U (NY)


• 1895 Cattell moves to Columbia U (NY)• As president of the APA Cattell convenes a

meeting



meeting• recommends they test

a) senses, b) motor capacity, and c) mental processes



meeting• recommends they test

a) senses, b) motor capacity, and c) mental processes

• Back in France Binet emerges on the scene


• Spearman gives birth to the g/s factor theory


• Henry Goddard emerges, and in 1908 visits Binet


• Binet’s ideas of testing move away from labels



• IQ = (Mental age/chronological age) *100• For example, (15/10) * 100 = 150



• IQ = (Mental age/chronological age) *100• For example, (15/10) * 100 = 150

• Ellis Island under Goddard

• WWI recruits under Yerkes & Terman


• 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 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


• Horn, student of Cattell, brings together work in the field and devises the

Cattell-Horn 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


• Meanwhile distinct factor analytic work by Carroll has led to

CARROLL’S (1993) THREE-STRATUM CARROLL’S (1993) THREE-STRATUM THEORY OF COGNITIVE ABILITIESTHEORY OF COGNITIVE ABILITIES g

GeneralIntelligence

FluidIntelligence

CrystallizedIntelligence

GeneralMemory &Learning

BroadVisualPerception

BroadAuditoryPerception

BroadRetrievalAbility

BroadCognitiveSpeediness

ProcessingSpeed (RTDecisionSpeed)

G

ener

al(S

trat

um II

I)

Bro

ad(S

trat

um II

) N

arro

w(S

trat

um I)

69+ narrow abilities found in data sets analyzed by Carroll

Gf Gc Gy Gv Gu Gr Gs Gt

(Carroll, 1993, 1997)

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

1. Linguistic2. Logical-mathematical3. Spatial4. Musical5. Bodily-Kinesthetic6. Interpersonal7. Intrapersonal8. 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

Binet ThurstoneTerman Yerkes

Wechsler Gardner CattellHorn

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?

Documents

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