Integration versus differentiation of fluid/crytallized intelligence in old age.

Used an intra-age simulation approach to evaluate several models of psychometric intelligence differing primarily along the developmental continuum of differentiation–integration for older adults. 109 adults (aged 60–89 yrs) were administered a battery of 17 ability tests selected to mark R. B. Catell's (1971) and J. L. Horn's (1970, 1978) fluid (Gf) and crystallized intelligence (Gc) and speed dimensions. Using the Gf/Gc model of intelligence and intermediate outcomes as guidelines, structural models with between 7 and 1 factors were successively evaluated by confirmatory factor analysis. Three main findings emerged. First, models with fewer factors provided better fits to the data. Second, a model with a general factor and 3 group factors was especially acceptable based on empirical and theoretical criteria. Third, it was not possible to obtain an acceptable solution for the older Ss that would directly parallel the Gf/Gc structural pattern of 1st-stratum factors reported for younger age groups. In concert, the findings support a neointegration, or dedifferentiation, view of psychometric intelligence in old age. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)