Crystallized intelligence as a product of speed and drive for experience: the relationship of inspection time and openness to g and Gc

The five-factor model personality domain of openness (O) is theoretically independent of intelligence and thus should not correlate with information-processing speed markers of general ability (g). Simultaneously, if information-processing speed is basic to g, then computational speed should correlate not only with g but also with subsidiary facets of intelligence, such as crystallized intelligence (GC). These important relationships were explored using the inspection time (IT) measure of information-processing speed together with the O scale of the NEO-PI R (Costa & McCrae, 1995) and separate psychometric tests of g (Raven's Matrices) and GC (vocabulary and comprehension). Raven's and the Gc measure correlated .598, while IT correlated with both Ravens (r=−.558) and GC (r=−.401) supporting a basic role of computational speed in g. O correlated significantly with GC (r=.338), but not with Raven's nor with IT. Structural equation modeling supported two models in which O was independent of g, with IT being basic to g, and with GC reflecting the joint action of g and O. Paths from O to IT or to Raven's were not significant, suggesting that any apparent relationship of O to intelligence is due not to effects of O on ability, but rather to the effects of O on interest in knowledge, a joint final path with ability.