Inspection time and WAIS-R IQ subtypes.

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Eighty-seven subjects from a diabetic outpatients' clinic were tested on the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and on a test of visual inspection time (IT). The correlation between WAIS-R Full-Scale IQ and IT was - .250 (p < .05). The correlation between the square root transformation of IT scores and the sum of WAIS-R performance subtests was -.421 (p < .00 1), and with the sum of WAIS-R Verbal subtests was -. 192 (n.s.). Principal components analysis indicated that IT had only a very modest loading on general intelligence. After Varimax rotation, two factors were obtained with eigenvalues greater than 1; IT had a high loading on the Performance factor but a near zero loading on the Verba[ factor. Confirmatory factor analysis revealed that a two-factor model of intelligence, with correlated Performance and Verbal factors and IT loaded on the Performance factor only. had a better fit to the data than a single latent factor model. This analysis also showed that IT had loadings significantly greater than zero on general and performance-ability factors. but that the loading of IT on the Verbal factor was not distinguishable from zero. IT appears to be significantly related to performance IQ but only weakly to Verbal IQ.

Original languageEnglish
Pages (from-to)223-236
Number of pages14
Issue number2
Publication statusPublished - 1993



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