Evolution of Intelligence Testing

Sir Francis Galton

• Nature v. nurture

• Invented concepts of correlation, and percentile scores

Alfred Binet

• 1st useful intelligence test (1905)

• mental age

Mental age

Mental performance typical of a child of that chronological age

Lewis Terman

• Stanford-Binet Intelligence Scale (1916)

• Intelligence quotient (IQ)

• can compare children of different ages

Intelligence quotient (IQ)

Mental age/chronological age x 100

David Wechsler

• Wechsler Adult Intelligence Scale [WAIS] (1939)

• Less dpendent of verbal ability; includes non-verbal reasoning

• separates scores for verbal, performance, and full scale IQ

• Disregards IQ in favor of a normal distribution

Reliability

• .9 correlation

• Sample behavior

• Score lowered by low motivation or high anxiety

Validity

• .7 correlation

• Only valid for academic work

High IQ is more likely to

land high-stakes jobs compared to low IQs

Do western cultures use IQ tests

yes

Do eastern cultures use IQ tests

no (except Japan)

IQ tests do not translate well into

the language and cognitive frameworks of non-western cultures

Adaptive skills

conceptual, social, and practical skills

Flynn Effect

IQ test scores have increased over the years because of environmental factors

Stereotype threat

The experience of anxiety or stress when someone has the potential to confirm a negative stereotype of their social group

Stereotype Lift

Increases performance when people are exposed to negative stereotypes about another group