Individual Differences: Intelligence Testing

Question 1

What are the key points in the study of individual differences?

Answer 1

1. Late 18th to 19th century: Phrenology
2. Late 19th to 20th century
   - Founders of individual differences: Francis Galton and Alfred Binet
3. Developing Scales
   - Lewis Terman (SBIS)
   - David Wechsler (WAIS)
4. 20th century
   - Use and abuse (ex. army selection for WW1, immigration, eugenics, 11-plus)
5. Theories
   - g-factor and heritability
   - Multiple intelligences

Question 2

Who were the three main protagonists of phrenology?

Answer 2

• Franz Josef Gall
• Johann Kaspar Spurzheim
• George Combe

Question 3

What is the study of phrenology?

Answer 3

• The reading of character and intellectual abilities through the ‘bumps’ on a person’s skull
• Assumes that larger bumps = larger ‘faculties within the brain’ = better
• Used a device called “craniometer” to measure different areas of the brain

Question 4

Describe how the study of phrenology was brought down

Answer 4

• Brought down by Alice Lee! around the 19th century
• Lee worked in Karl Pearson’s laboratory and measured skull sizes to test its relationship with intelligence
• Found that the correlation did not exist (brain size has nothing to do with intelligence)

Question 5

What are Francis Galton’s contributions?

Answer 5

• Founder of psychometrics
• Started the use of normal curves, sampling, correlation coefficient
• Focused on the variability of characteristics between people; Argued that trait differences are large and innat
• However, he had a strong sexist and racist bias (ex. coined the term, eugenics)

Question 6

Describe Galton’s (bizzare) investigation/experiment

Answer 6

• Gathered 9000 volunteers who paid to contribute measurements (ex. physical measurements like head size, reaction times, sensory discrimination)
• These measurements did NOTHING; Galton was not measuring the right things as his subject of measurements were unrelated with intelligence
• But this interest in (and measurement of) individual differences was the foundation of differential psychology

Question 7

Charles Spearman and The g-factor

Answer 7

• Early 20th century; English psychologist
• Suggested that there was a general factor in intelligence, called the g-factor
• Observed that school children’s scores on different kinds of tests had a correlation across the tests
• Two factor theory of intelligence: g + specific factor

Question 8

What are Alfred Binet’s contributions to individual differences?

Answer 8

• In the early 20th century, he designed the first usable intelligence test (tgt with Theodore Simon)
• Developed to assess children within the French education system to identify those with special needs

Question 9

Explain intelligence quotient (IQ)

Answer 9

• The mental age of an individual
• Different from chronological age, which is how old the person actually is
• IQ = (Mental Age)/(Chronological Age) x 100

Question 10

Name two intelligence tests

Answer 10

1. Stanford-Binet Intelligence Scale (SBIS)
   - Commonly used to measure intelligence in children and young adults, no use for adults
2. Wechsler Scales of Intelligence
   - Deviation IQ
   - Standardization against a representative adult population (M = 100, SD = 15)

Question 11

Describe the use and abuse of intelligence tests

Answer 11

• WW1; The APA (at that time, led by Robert Yerkes) developed ‘Alpha’ and ‘Beta’ intelligence tests to aid job allocation to draftees
• This impacted upon immigration policies, which resulted in many being stranded in Europe in the 1930s
• This also impacted upon eugenics

Question 12

Describe the Heritability Legacy

Answer 12

• How can we answer the question, “Is intelligence a single thing, and is it innate?”
• First, by analysing correlations between many tests of aptitude and looking for general vs specific factors
• Second, by trying to examine how much of ‘it (g-factor) is down to genes

Question 13

Issues with intelligence testing

Answer 13

• Cultural bias
• The Bell Curve controversy (intelligence is going up and up and up, shifting over time and it changes constantly)
• The Flynn Effect (gradual rise in IQ across time)

Question 14

What are Louis Thurstone’s contributions to intelligence testing?

Answer 14

• Multiple intelligences
• 20th century. Used factor analysis to describe the set of Primary Mental Abilities (7 items)

Question 15

What are Howard Gardner’s contributions to intelligence testing?

Answer 15

• Multiple intelligences
• Late 20th century. Described the different abilities we have, intelligence branched into 8 items

Question 16

Describe Robert Sternberg’s Triarchic Theory of Intelligence

Answer 16

• Late 20th century
• Cycle between (1) Analytical Intelligence, (2) Practical Intelligence, (3) Creative Intelligence