Who is Francis Galton?
- Science of finger printing
- Forefather of intelligence testing
- Believed people differed in intelligence
- The ability to respond to the large range of information available to the senses
- e.g. discriminate between hot and cold; reaction time; keenness of sight and hearing - some since discarded; RT still very much in use.
- First explored intelligence
Who is Alfred Binet?
-In 1904 French government commissioned Binet to devise techniques to identify children who needed extra/alternative schooling.
-Goal to identify weaknesses in children where extra help is needed
-Developed (with Theodore Simon) a series of short tasks (easy to hard):
– Following a lighted match with your eyes (easy)
– Naming parts of the body; repeating sentences (medium)
– Reproduce a drawing; recall digit strings (difficult)
Who introduced the concept of age testing?
- Alfred Binet
- Introduced the concept of age
- How well is child doing compared to his/her age group
- This legacy is still with us today (e.g. reading age)
Who is Lewis Terman?
- Moves to the US
- Terman uses the Binet-Simon test on Californian school-children
- Made revisions: Stanford-Binet test
- Highlighted the need for standardised tests based on representative samples
- What scores really mean, e.g. a high score, low score, medium score
Who is Robert Yerkes?
- President of APA
- When the US entered WW1 (1917) he was asked to consider how psychology could help the war effort.
- They wanted to quickly classify recruits to perform suitable roles
- Wanted to know how to win the war
What is the Army alpha test? (Robert Yerkes)
– Language and knowledge-oriented tasks
- Use synonyms and antonyms
- Follow oral directions
- Practical judgement (e.g. correct solution to a presented scenario)
What is the Army beta test? (Robert Yerkes)
– Less language oriented
- Maze task
- Cube analysis (counting cubes)
- Matching numbers to symbols
- Geometric construction
What was the outcome for Robert Yerkes’ army testing?
- Didn’t turn out to be very useful for WW1
- But well over a million people were tested
- The tests interested broader society (e.g. businesses, education sector).
Who is Charles Spearman?
- Early 20th century
- Back to the UK
- How do cognitive tests relate to each other?
- Spearman collected data on a range of cognitive tests
- Noted a positive manifold – Test performance across a range of domains showed positive correlations
- Developed factor analysis
What is Spearman’s g?
- Used factor analysis on these data
- Discovered a consistent general factor - Spearman’s ‘g’ (g = general factor of intelligence)
- Believed that g reflected a kind of mental energy; a deeper fundamental mechanism
- Also posited specific factors - Two-factor model: g and specific factors
Who is David Wechsler?
- After Spearman
- US based; Columbia University
- In the 1930s he set about developing a standardised test that would capture general and specific intelligence
- Work led to a standard measure in wide use today - Wechsler Adult Intelligence Scale (WAIS)
- Task domains include: arithmetic; block design; comprehension; digit span; information; object assembly; picture arrangement; picture completion; vocabulary
- Get a sense of where ‘normal’ was in the population, mean of 100 (if you score 100, you are 100)
How do you test working memory?
- Digit recall
- Given a string of numbers to remember
What is the WAIS intelligence test?
-WAIS measures overall intelligence and 11 other aspects related to intelligence that are designed to assess clinical and educational problems
What is the Caroll’s Three-Strata Model?
- Carroll’s Three-Strata Model (g factor sits above all the other sub domains.)
- High g means you have broad abilities
- Stratum 3: general. Stratum 2: broad abilities. Stratum 1: narrow abilities
Who is Howard Gardner?
- Education and psychology, not psychologist
- Theory of Multiple Intelligences – e.g. linguistic; spatial; musical; bodily kinaesthetic; interpersonal; intrapersonal
- Very widely known
- Small evidence base, didn’t test it only proposed it
What are the criticisms of Howard Gardner?
- No tests of his model of intelligence exist
- Does not take into account the positive manifold; g factor
- He largely fails to respond to criticism
Can intelligence predict educational achievement?
- Age 11 general intelligence > Age 16 GCSE scores (Deary et al (2007))
- Intelligence is highly correlated with educational achievement
- Class doesn’t affect
Can intelligence predict wage outcome?
- Ceci and Williams (1997)
- Looked at wages which people received and compared with cognitive ability
- Wages increase as cognitive ability increases
Can intelligence predict political views?
- Deary et al (2008)
- Children’s intelligence does correlate with parent’s social class
- General ability and social class (independently) affect education
- Smarter children lead to higher occupational social class, lead to liberal attitudes
- Intelligence in childhood can predict adult political views
Can intelligence predict religious views?
- Lewis et al (2011)
- Fundamentalism – the bible should be strictly followed (bible is the word of god)
- Lower education, were more fundamental
- Lower in openness, more likely to be fundamental
- Age or sex did not matter
- Lower intelligence leads to more fundamental views
Can intelligence predict mortality?
- Calvin et al (2011)
- A 1-standard deviation advantage was associated with a 24% lower risk of death (17 to 69-year follow-up).
- Childhood socio-economic status had no impact on this relationship…not a confounder of the intelligence– mortality association.
- Controlling for adult SES…and education…attenuated the…hazard ratios by 34 and 54%, respectively.
- Smarter you are, less likely you are to die
Are there sex differences in intelligence?
- Some longstanding assumptions: Males > Females
- Most current data don’t support this claim
- However, there seem to be sex diffs in variance – Arden & Plomin (2006)
- Men and women don’t differ at the mean level of IQ
- Sex differences in the sub-domains
- Men are more variable than women, range of higher and lower scores
Criticisms with IQ tests
- Test-retest reliability (no substance to what you did in an IQ test)
- Wrong to distil people down to one number
- IQ tests only measure how good you do on IQ tests (no real world validity)
- Culturally biased
Are IQ tests reliable?
- Deary et al (2000)
- Validates IQ tests
- Tested children for psychometric intelligence and followed up with the same test when they were 77.
- Correlation .63, e.g. there is a relationship
