Human Abilities I: Structure
Reading • Start with Ch. 7 in Cooper (1998) • Or Brody (1992) • Or Cooper (1999 ch. 1 & 2) & pp. 55–9
Learning Objectives • Following the lecture & reading you should be able to:– • Show an understanding of the nature of human abilities & attainments • Evaluate the models of Spearman & Thurstone, & hierarchical models • Comment on some other approaches (Guilford, Gardner, Howe)
Definitions • Mental ability • Attainments • IQ
Spearman’s model Spearman (1904) • Gave several ability tests to children • Factor-analysed the correlations • 3 possibilities • All the skills are uncorrelated (1 factor) • All the skills are correlated (no factors) • Certain "groups" of skills correlate together (>1 factor)
Spearman ctd • Spearman found that ONE FACTOR was needed to describe these data. • He called it g (general ability) • So a child’s performance on any test is attributable to • g • specific variance • random error
Thurstone (1931/8) • Did much the same but found not one but NINE factors • Primary Mental Abilities (PMAs) • Verbal comprehension vocabulary , analogies • Word Fluency anagrams, spelling • Numerical Ability • Memory • Induction (e.g., number series)
PMAs ctd • Spatial Ability (visualising shapes) • Perceptual Speed (comparing strings) • Mechanical Knowldge & ability • Deductive Reasoning (applying a logical rule) • There is a HUGE number of potential PMAs • Which you find depend on what you assess! Use a v. broad range of tests.
Why the difference? • More homogeneous (student) sample • More tests • Newer methods of factoring • Simpler tests. • Spearman gave (e.g.,) a maths test comprising addition, geometry etc. • Thurstone treated addition, geometry etc. as seperate tests.
Hierarchical models • It was found that Thurstone’s factors were themselves correlated. • Factor analyse the correlations between these factors and get g at the ‘second order’?
Horn & Cattell (1976) • Developed tests to measure 20+ PMAs • Factored the correlations between these PMAs: Obtained 6 “second order” ability factors.
the Horn-Cattell Second-Order Abilities • fluid intelligence (reasoning) • crystallised intelligence (requires knowledge) • visualisation (of shapes) • retrieval (memory) • fluency (speed of creating new ideas/associations) • cognitive speed (speed of processing)
Horn & Cattell: ctd • When these 6 second-order abilities were factored, found g at the third-order • g was very similar to fluid ability • Gustaffson’s (1981) model is highly similar. So is Carroll’s (1993) 3-stratum model. • Investment theory - fluid/crystallised ability.
Guilford’s (1967) SI model (Structure of Intellect)
Guilford’s (1967) Structure of Intellect (SI) model • Not based on factor analysis • Assumes 5 basic mental operations (cognition, memory, convergent thinking, divergent thinking, evaluation) • 4 contents (figural, symbolic, semantic, behavioural) • 6 products (units, classes, relations, systems, changes, implications) • So 5 x 4 x 6 =120 distinct abilities
Howard Gardner’s (1983/1993) theory of multiple intelligences
Gardner’s model • Eschewed factor analysis on the basis of criticisms made by Gould (1981) • Performed literature search to identify “multiple intelligences” • These he assumed to be independent of each other... • ...which is odd, given the evidence for g!
Gardner’s abilities are bundles of behaviours which... • disappear/are retained following damage to some area of the brain • are found together in prodigies/idiots savant • be related to a particular stimulus - e.g. pitch perception or imitation • show a clear developmental trend • interfere/transfer together (so common neural mechanism) • each have a system of symbols for concepts
Gardner’s intelligences • linguistic • musical • logical/mathematical • spatial • kinaesthetic/bodily • integrity of self-concept • quality of interactions with others
Issues... • Are these all cognitive? • Is the list exhaustive? Why no ‘sexual intelligence’ for example? • Why assume they are independent, rather than test it empirically? • Popular with teachers who are eager to view children as having unrelated abilities: ‘play to strengths’.
1. Factor analysis is useless • “there may be a number of alternative patterns to be discerned, and factor analysis does not identify any one pattern that is uniquely present in the data” • ?? • Simple-structure rotation does find a unique solution
2. Twin studies are flawed • ...so no evidence for biological mechanisms • But he only considers • separated identical twins, and • certain post-hoc objections which he claims over-estimate genetic influences; others which over-estimate environmental influences are ignored!
3. Biological correlations are trivial in size • see next lecture. • Are correlations of 0.4 really so small that they can be ignored?
Summary • You should now be able to:– • Show an understanding of the nature of human abilities & attainments • Evaluate the models of Spearman & Thurstone, & hierarchical models • Comment on some other approaches (Guilford, Gardner, Howe)