2. What is intelligence and can we measure it?. Definitions are fuzzy:Verbal ability, problem solving skills and the ability to adapt to and learn from life's everyday experiences' (Santrock, 2000)Hard to test - 3 problems:unitary or multifactorial?culture biaseffect of environment / genes.
1. 1 10: Intelligence Outline
What is intelligence and how do we measure it?
Does intelligence change over time
How does our genetic inheritance interact with our environment?
2. 2 What is intelligence and can we measure it? Definitions are fuzzy:
‘Verbal ability, problem solving skills and the ability to adapt to and learn from life’s everyday experiences’ (Santrock, 2000)
Hard to test - 3 problems:
unitary or multifactorial?
effect of environment / genes
3. 3 Problem 1: Unitary or multifactorial? Is intelligence a unitary or multifactorial concept?
Binet - unitary concept -> IQ tests
Originally: IQ = [MA/CA] x 100 (ration IQ)
Now: comparison with children same age; average 100, sd=15 (deviation IQ)
Spearman (1927) - g
Others - multifactorial concept:
Catell (1971, 1987)
4. 4 Distribution of IQ scores (From Bee, 2000)
5. 5 Hierarchical models Cattell, 1971
General intelligence (top of hierarchy)
Acquisition of new information
Grasping new relations
Accumulation of knowledge over lifespan
6. 6 Hierarchical models (Carroll, 1993)
7. 7 Multiple intelligences Thurstone (1938)
7 primary mental abilities
Perceptual speed Gardner (1983, 1993)
8 frames of mind
Naturalist – ability to understand natural and man-made systems
Evidence? Savant skills
8. 8 Sternberg’s TRIARCHIC theory Multidimensional Abilities Test: tested 3 components:
Componential (or analytical)
Planning, organising, remembering facts
Experiential (or creative)
Insight, ability to see connections
Contextual (or practical)
“street smarts”, practical solutions – which box of cereal is the best value?
9. 9 Wechsler scales Verbal tests
10. 10 Problems Evidence
Not a lot of evidence for different methods
Lack of research?
Lumpers vs splitters
Lumpers: intelligence stems from one general ability
Splitters: many separate kinds of relatively independent intelligence (modular?)
Also: Hierarchical organisation of specific skills stemming from 1 or 2 factors.
How many intelligences are there?
We have contextual intelligence or musical intelligence
Why not chess, law, writing, poetry intelligence?
11. 11 Problem 2: Cultural bias Different emphases on important components of intelligence (Rogoff, 1998, Serpell, 2000):
West: abstract thinking and logic
Kenya: responsible participation in life
Uganda: one who knows what to do and follows it through
Papua New Guinea: recall
Caroline Islands: navigation by stars
12. 12 Solution? Culture fair tests Ask fair questions - relevant to all
Raven’s Progressive Matrices Test
Cultural differences even in drawing (Anastasi & Urbina, 1996)
13. 13 Raven’s Progressive Matrices (From Thornton, 2002)
14. 14 Does intelligence change over time? Infant intelligence
no verbal intelligence scales
more items measuring perceptual motor development and social interactional abilities
Gesell (1925, 1928)
motor, language, adaptive, personal-social skills
Bayley Scales of infant development
Bayley (1969; 1993)
motor scale (e.g. crawling, climbing stairs)
mental scale (e.g. response to sound, imitation, memory, problem solving, language comprehension and production)
15. 15 Does intelligence change over time? NO correlation between infant and IQ test scores (Anderson, 1939).
But scales measure different things
Other infant measure correlate with IQ:
habituation experiments (Bornstein, 1989)
attention (Bornstein & Krasnegor, 1989)
Stability over time?
16. 16 Evidence for stability 3 yrs onwards – start to get consistency
High correlations between IQ scores at 6, 8, 9 and 10 years
High correlations between IQ in childhood and at 18 years
-> conclude stability over time?
17. 17 Evidence against stability of intelligence over time Performance of a single child retaking same test at different ages CAN fluctuate
McCall et al 1973:
1/3 children’s scores fluctuated by 30 points
1/7 children’s scores fluctuated by 40 points
18. 18 More evidence against stability Environmental influences affect intelligence:
Abeccedarian project (Ramey & Campbell, 1984; Ramey and Ramey, 1998):
effect of activities aimed at improving language, motor, social and cognitive skills
Lots of intervention programs with fraudulent claims (Eysenck, 1998)
Claimed improvements not found
19. 19 How does our genetic inheritance interact with our environment? Research follows several lines
MZ/MZ comparison (separated)
Adopted children/Bio parents/Adoptive parents
21. 21 How does genetic inheritance work? 70-80% determination of IQ by heredity
Assumption: 2 bright parents produce bright child
BUT NOT STRICTLY TRUE
Laws of heredity predict regression to the mean
Children of bright parents will, on average, be bright – but less bright than parents
22. 22 Summary Issue 1: what is intelligence and can we measure it?
Unclear what intelligence is
almost certainly bound to be multifactorial
but problems -> hard to measure
Issue 2: is it stable over time?
lots of evidence either way.
Issue 3: nature-nurture debate
general conclusion that 70-80% of IQ difference can be explained be genetic differences
BUT: mustn’t make the mistake of interpreting this too simplistically
23. 23 Learning Outcomes & Reading Describe and evaluate theories of intelligence and the tests designed to measure it
Debate the issue of whether intelligence is stable over time and be able to describe and evaluate the relevant research
Be able to describe and evaluate studies that throw light on the interaction between genetic inheritance and environment.
Essential Reading (on Digital Resources):
Gardner , M. & Clark, E. (1992) The psychometric perspective on intellectual development in childhood and adolescence. In R. J. Sternberg & C. A. Berg (Eds).Intellectual development. Cambridge: Cambridge University Press
Grigorenko, E.L. (2000). Heritabililty and intelligence In R. J. Sternberg (Ed). Handbook of intelligence. Cambridge: Cambridge University Press.
Meadows, S. (1993) The child as thinker. Hove: Routledge. Ch 3. pp.157-196
See pdf handout
24. 24 Questions to ask What are the problems with the measurement of intelligence?
What do the different theories say about the nature of intelligence?
What does the research suggest about the nature of intelligence?
Is intelligence stable?
How can theory and research help us deal with the measurement of intelligence?