Lecture 2 - Measuring individual differences Flashcards
(43 cards)
What did Quetelet do?
Tried to define the ‘average man’ through statistics
- systematic application of statistical methods to humans
- he didnt just do physical properties, but psychological ones too
- developed Body mass index - aka Quetelet index
- he found that BMi sat on a normal distrubution graph - each individual could compared to the norms of this graph
- “weight increases as a square of the height”
In terms of depatures from the average, What was Galton interested in?
- significantly influenced by Quetelet
- looked at differences - those who deviated from the average
- More interested in those at the top end than the lower end
- Came up with standard deviation
What work did Spearman do?
- Developed statistical methods to study latent variables - underlying traits responsible for our intelligence
- notion of ‘g’
- Developed the use of factor analysis to find ‘g’
Outline factor analysis
- exploring patterns of correlations between items on a particular measure
- data-reduction - identify similarities
- trying to find general, underlying categories by fitting things into it
What did Spearman test kids with?
- memory
- spatial abilities
- math abilities
- vocab
Outline Positive manifold
Spearman found if you were intelligent with one domain, you were intelligent on the others
- supports underlying ‘g’
Outline spearmans theory of intelligence
General intelligence ‘g’ = mental energy that underlies intelligence. It is a deep fundamental mechanism
CAUSES
Specific Abilities ‘s’ = e.g. maths intelligence, spatial intelligence, verbal intelligence
g and s combine to create intelligence
What did Spearman inspire? A race to develop what?
inspired a race to develop a good intelligence test based off ‘g’
Outline the Wechsler Tests
Much broader domains that test a number of different abilities
- Wechsler -Bellevue Scale (1939)
- Wechsler Adult Intelligence scale (WAIS) 1955
- for ages 16-75 - Wechsler Scale for Children (WISC)
- 5-16
What did Terman (1916) contribute?
Intelligence quotient (IQ) IQ = 100 X (mental age ÷ chronological age)
Couldnt apply to adults as age would keep increasing but intelligence would be similar - so Wechsler came up with the WAIS instead
Outline the WEIS (1955)
- first to assess non-verbal/ spatial tests
- tested stuff like verbal comprehension, working memory, perceptual organisation, processing speed etc
- focused on comparing scores to others of the same age
IQ = 100 X (actual test score ÷ expected test score)
- did it to large groups to establish norms
- overall score is based on deviation from standardised norms - “deviation IQ”
Outline Raven’s Progressive matricies (1938)
- Based on concept of ‘g’
- a test that is free of cultural influence as it includes non-verbal problems and abstract reasoning
- made this one as it seemed western people did better on verbal tests - wasnt fair
- overall score is based on deviation from standardised norms
Outline thurstones 7 primary mental abilities
‘g’ is made up of:
- Perceptual speed
- Associative memory
- Spatial visualisations
- Number
- Verbal comprehension
- Word fluency
- reasoning
What did Thurstone criticise spearman of doing?
said all the things spearman measured had language skills behind them - which could explain why there is positive manifold
- so he made 7 distinct ones
Outline Cattell’s theory of intelligence
General intelligence ‘g’, is made up of 2 things:
- Gf - fluid intelligence - innate
- stuff like primary reasoning/ problem solving
- cant be taught - Gc - Crystallised intelligence - learned/ developed
- e.g. factual knowledge, education
Outline Carroll’s theory of intelligence
Three-Stratum Theory of Cognitive Abilities
- questioned what was in between ‘g’ general intelligence and ‘s’ specific intelligences
- Argued g was stratum 3
- then there was stratum 2 - visual, auditory, memory, cog speed, processing speed etc
- and then stratum 1
- then tests
- then specific abilities
Whats a limitation of Carrolls theory?
X - very complicated - cant really use for IQ tests
Outline the combined model of Cattell-Horn-Carrol
- suggests there are 16 broad intelligences, each of which divides into sub-categories
What did Tiedemann (1836) suggest?
Argued that the size of the brain was an indicator of our mental energy
Outline McDaniel (2005)
Found that brain size and IQ correlated (.03)
- no study has ever found a negative correlation
What did Toga & Thompson (2005) find?
Found evidence for heritability of brain size
Define Elementary cognitive tasks
very simple tests that assess cognitive processing speed and processing accuracy
- reaction time is key
- intelligence is determined by speed and accuracy of response
√ - dont require any previous knowledge
What did Deary et al (2001) found with ECT’s
moderate correlation ebtween IQ and RT tests
Give an example of Jensen’s RT elementary cognitive tasks
The jensen box
- supports the notion of ‘g’ as no previous knowledge/ background intelligence is required
- 8 lights on it, with finger on bottom middle one
- as soon as a light comes on, the speed to press it is measured
- Speed of pprocessing is seen as an underlying marker of intelligence
X - is there a cultural bias?
