Characterizing mature human intelligence - Expertise development

Results from a study of 263 male players at 48 levels of expertise in the game of GO, and ranging from 18 to 78 years of age, suggest a need to revise the extended theory of fluid (Gf) and crystallized (Gc) intelligence to take account of continued development of intelligence throughout adulthood. The extended theory of Gf-Gc is based on evidence that Gf, short-term apprehension and retrieval (SAR) and cognitive speed (Gs), decline with age over adulthood. Results from a number of studies, however, suggest that within the domains of expertise, high levels of reasoning, feats of memory and speeded thinking similar to Gf are displayed by older adults. To explore this hypothesis, measures of reasoning, memory and cognitive speed were constructed within the domain of expertise related to playing the complex game of GO. Analysis of the structure of the GO-embedded measures and standard measures of Gf (SAR and Gs) indicated a form of short-term memory - labeled expertise working memory (EWM) - that had substantially wider span than the short-term working memory (STWM) of SAR. This finding is consistent with the hypothesis that long-term working memory is built up during the course of developing high levels of expertise. The results also suggest that a form of expertise deductive reasoning (EDR), utilizing EWM and incorporating large stores of knowledge, is distinct from Gf. Expertise cognitive speed (ECS), however, was not found to be reliably distinct from the Gs factor. Analyses of cross-sectional age differences indicate an age-related decline in both EDR and EWM, but as higher levels of expertise are reached, age-related decline does not occur. To the extent that there is continued press to advance expertise throughout adulthood, there may be improvement, decline, in the EDR and EWM forms of intelligence. (C) 2001 Elsevier Science Inc. All rights reserved.