Intelligence

One of the long standing debates in psychology is the underlying nature of intelligence. What defines intelligence? What behaviours or abilities, as a society, do we deem to be those of an intelligent individual?

Psychologists generally agree that the term intelligence “describes a person’s ability to learn and remember information, to recognise concepts and their relations, and to apply the information to their own behaviour in an adaptive way” (Martin, Carlson & Buskist, 2007). However, defining the exact nature and inner workings of intelligence is where psychologists are of different opinions. It has even been suggested that intelligence is “that which the intelligence tests measure” (Reber, 1995).

Psychologists generally fall into one of two categories when trying to understand intelligence. Those who believe there is an underlying ‘general’ intelligence factor, as proposed by Spearman (1927) and Cattel (1966), and those who believe that there are multiple intelligences operating simultaneously, outlined in the theories of Thurstone (1938) and Gardner (1983).

Factor analysis, a procedure developed by Spearman and Pearson which is “used to determine the minimum number of dimensions or factors that account for the observed relationships (correlations) among subjects responses over a large

number of different tests” (Atkinson, Atkinson, Hilgard 1983) has further allowed psychologists to understand the nature of intelligence.

Spearman proposed that an individuals intellectual ability was controlled by two factors, the g factor, the measure of general intelligence, and the s factor, which related to the specific ability concerning a particular test. He further defined the g factor as comprising of ‘three principles of cognition’: apprehension of experience, the ability to understand what they experience, eduction of relations, the ability to understand relations between two things and eduction of correlates, referring to a subjects ability to apply a rule from one case to another (Martin et al.). Spearman believe that a persons performance on any given intelligence test was determined by how well they applied these three principles.

A major strength supporting Spearman’s theory can be found in the correlations on tests of ‘differing’ intellectual abilities, that is to say how closely the various abilities are related. It’s logical to assume that correlations on tests of independent, separate abilities would have correlations approaching zero. But it has been found the correlations amongst various tests of intellectual ability range from 0.3 to 0.7. Or more precisely they have 9 per cent to 49 per cent of their variability in common (Martin et al.)

Building on these correlations Spearman employed factor analysis to further attempt to define the nature of intelligence. Essentially the procedure of factor analysis is used to determine which set of tests form groups (Martin et al.) E.g. If scores from several different people over a number of different tests