Effects of aging and pathology on the factorial structure of intelligence.

Abstract

A factor-analytic study of the structure of intellectual functioning as measured by Wechsler tests was carried out on 4 samples of varying pathologies and 4 normal samples of varying ages. Applying objective analytical oblique rotation and statistical measures of factorial similarity, 3 main factors and 1 quasi-specific described most groups. In distinction to previous studies, both pathology and normal aging were found to introduce some degree of factorial variability, with the effect of age seemingly more pronounced. Thus, pathological samples did not differ from age-matched normals, though normals of different ages varied from each other. The results were discussed in terms of the relative importance of the different factors, process-reactive distinction in schizophrenia, and the particular vulnerability of the Memory factor.

Factor Analysis of the WAIS and Twenty French-Kit Reference Tests

“…The third strongest factor was Factor 4, Memory Span, explaining 7.18% of the subscale variance. Berger, Bernstein, Klein, Cohen, and Lucas (1964) and Cohen (1957) have reported a similar factor. None of the previous analyses seem to have shown quite as distinct a Memory Span factor as the present results.…”

“…Davis (1956) did not include reference tests for this factor; the closest factor he reported was a Similarities factor which had large loadings only from two similarities tests. In other analyses (Cohen, 1957;Berger et al, 1964) this factor seems to have been combined with Verbal Comprehension to form a single verbal factor. The identification of Syllogistic Reasoning as the dominant factor in Similarities and Comprehension does not seem to have been determined previously.…”

Intellect, perceptual characteristics, and weight gain in anorexia nervosa

“…Although Block Design does not contribute very much, it is interesting to note that it follows Digit Span and Arithmetic in the amount of contribution to the variance explained (R' = .07). While factor analyses of the WAIS consistently show Block Design as primarily loading on a Perceptual Organization factor, it periodically has a fairly significant loading on the Freedom from Distractibility factor, which Digit Span and Arithmetic primarily load on (e.g., Berger, Bernstein, Klein, Cohen, & Lucas, 1964). On the other hand, multiple regression analyses of Rorschach data yield disappointing results; no variable accounts for any sizeable contribution.…”

The Freedom-From-Distractibility Factor: an Examination of Its Adaptive Behavior Correlates

“…In a majority of these analyses, the two factors correspond closely to Wechsler's a priori division of the scale into Verbal and Performance sections (Silverstein, 1969(Silverstein, , 1977(Silverstein, , 1980. This factor, however, has proven to be less robust and less invariant across different clinical samples (Berger et al , 1964;Groff & Hubble, 1982;Kaufman, 1979;Reed & Fitzhugh, 1967;Rugel, 1974;Silverstein, 1970). In addition to the Verbal and Performance factors, a number of studies have extracted a third factor (Baumeister & Bartlett, 1962a, 1962bBerger, Bernstein, Klein, Cohen, & Lucas, 1964;Cohen, 1952Cohen, , 1957Cohen, , 1959Russell, 1972;Van Hagen & Kaufman, 1975).…”

“…On all these tests, a Verbal factor and a Performance factor have been identified under a variety of extraction techniques and in various classes of subjects. In addition to the Verbal and Performance factors, a number of studies have extracted a third factor (Baumeister & Bartlett, 1962a, 1962bBerger, Bernstein, Klein, Cohen, & Lucas, 1964;Cohen, 1952Cohen, , 1957Cohen, , 1959Russell, 1972;Van Hagen & Kaufman, 1975). Generally, the Vocabulary and Information subtests load most highly on the Verbal factor, while the Performance factor is best characterized by the Block Design and Object Assembly subtests (Silverstein, 1969(Silverstein, , 1977(Silverstein, , 1980.…”