On the Asymmetry of g

Abstract

In this paper the strength of general intelligence at different levels of g is explored. This represents a replication of 1996 work by Dreary, et al. using a very large sample of young persons. By examining differences in correlation between subscales and by undertaking a confirmatory factor analysis of a standard ability measure, the Armed Services Vocational Ability Battery, at high and low levels of g (n = c. 600 at each level), it is shown that at lower levels of g the factor structure is quite similar to, although not as well defined as, the factor structure for the complete sample, that is, a single general factor; however, at higher levels of g, the factor structure is not as clear-cut. The differences in mean correlations between the high and low intelligence groups ranged from .12 to .46 depending on the specific analysis. We established the level of g in three different ways using different indicators of g with different strengths and weaknesses. Results of all three analyses converged. The results imply that people with high intelligence demonstrate this in quite different ways, while those with low g have intellectual deficits in all domains of intelligence. The dominance of g in the factor structure reflects this similarity of scores at the low end of the set of abilities. The prevalence of specific abilities is due to the variety of ways in which people can demonstrate high ability. One can visualize this in three dimensions by imagining the various abilities as flowers arranged in a narrow vase—at the bottom they are bound together tightly, at the top they spread out broadly.