Not all psychologists are sold on the idea of a unitary intelligence, as usually represented by Spearman’s g factor and the notorious single IQ measure. There have been a number of attempts to de-construct intelligence, (such as Butcher, 1970) but one which has commanded most attention is Gardner’s (1984) theory of “multiple intelligences”. This sounds slightly weird, like multiple personalities, but it is really quite simple. Instead of concentrating purely on correlations and factor analyses of tests, Gardner draws on disciplines such as neuroscience to examine abilities which appear to be largely independent of each other. Thus, he discusses ways in which they may be impaired by brain injury, while other faculties are left intact; or occasionally appear in isolation, as in the case of idiots savants. On this basis, he suggests that the following cognitive abilities are substantially independent of each other at a neuropsychological level:
- Linguistic intelligence
- Musical intelligence
- Logical-mathematical intelligence
- Spatial intelligence
- Bodily-Kinesthetic intelligence
- Intra-personal intelligence
- Inter-personal intelligence
More recently, Goleman (1996) has suggested that there is a feature of personality or even character which he calls “emotional intelligence”, and regards as distinct from these other "intelligences" already proposed. By this stage in the discussion it is difficult to know just what kind of personal attributes one is discussing.
There is a clear overlap with Hudson’s distinction between convergent and divergent thinking. The suggestion is that ability in one form of intelligence does not necessarily imply ability in others: hence, for example, it is possible to have linguistically very fluent people who cannot read maps or make sense of diagrams (spatial intelligence). Nevertheless, there do seem to be overlaps, as the diagram suggests (if you can read diagrams!): musical and mathematical abilities seem to go together quite frequently, for example.
The implication for teaching is considerable, insofar as these abilities relate to different ways of absorbing information and learning: I like diagrams, for example, and find them useful and concise ways of expressing ideas, but they may well baffle others. For some people, an argument expressed in words may be incomprehensible, but express it in the notation of formal logic and it becomes clear at once. None of these people is in absolute terms “brighter” than another, but is more “intelligent” (or more “responsive” or more “stimulated”?) in certain modalities.