The Relationship Between WAIS-R Abilities and Speed of Processing in a Word Identification Task

Matched to the proportions found in the U.K. census data for a range of demographic variables (age, sex, and socioeconomic status) 123 participants were tested on the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and a test of the minimum presentation time required to identify tachistoscopically presented words. The correlations between the sum of the scaled scores for Full, Verbal, and Performance subtests and the log of the identification measures were -0.40, -0.22, and -0.5 I, respectively. These results are in line with those observed between the WARS-R measures and standard visual inspection time (IT). Confirmatory factor analysis indicated that a three-factor model of intelligence with Verbal, Performance, and Attention/Concentration factors, and with the identification threshold loaded on the Performance factor alone, represented a better fit to the data than either a single general factor model or a two-factor model with Verbal and Performance factors. These results are in line with findings in the IT literature (Deary, 1993) that speed of information processing is significantly related to performance IQ but not to verbal IQ.