Dynamic mutualism versus g factor theory: An empirical test

The positive manifold associated with correlation matrices of diverse batteries of cognitive abilities has garnered a substantial amount of psychometric and theoretical consideration. General (g) factor theorists purport the positive manifold to be due to a g factor, which is believed to be representative of an important psychological construct. By contrast, the dynamic mutualism theory of the positive manifold asserts that it is an epiphenomenon, which emerges progressively during development, as a consequence of mutually beneficial interactions between originally uncorrelated cognitive processes. To test the competing dynamic mutualism versus g factor theories of the g factor, the strength of the g factor (as estimated by omega hierarchical, ωh) was plotted across the ages of 2.5 to 90 years (N = 5200). Although there was an observed increase in ωh from the ages of 2.5 to approximately 10.0, the observed slope was weak in magnitude. Furthermore, the results based on the mean of the bifactor model g loadings suggested that much, if not all, of the upward slope in ωh was due to differences in the number of subtests across age groups. Consequently, the results are interpreted to suggest that the dynamic mutualism theory of g was failed to be confirmed, however, important limitations associated with this investigation are highlighted and an alternative explanation is presented.