The factorial structure of the WAIS between early adulthood and old age.

Abstract

"The WAIS standardization data for four age groups (18-19, 25-34, 45-54, and 60- over 75) were separately factor-analyzed using complete centroid extraction, blind oblique rotation to simple structure and a positive manifold, and a second-order analysis into a general factor and orthogonal primary-specifics." Among the conclusions were the following: "Three major correlated factors, Verbal Comprehension, Perceptual Organization, and Memory, are found with striking consistency over the age range studied. These are the same factors as have previously been reported for the Wechsler-Bellevue" and "only one exception to factorial invariance over age occurs. In the 60- over 75 group, the Memory factor undergoes a sharp increase in variance at the cost of the general factor. Thus, in aged subjects, intellectual performance, even on verbal tests, becomes dependent to a noteworthy degree on memory ability." 20 references.