Information processing components of substitution test performance

Although substitution tests have been included in tests of intelligence for years, the underlying abilities they measure have still not been clearly determined. This study used componential analysis to investigate the information-processing components underlying substitution test performance. The bases of sex and age differences were also of interest. One hundred subjects from each of three age groups (9–11, 18–25, and 60–89 years) were tested.The componential analysis found that substitution tests measure perceptual speed and, to a lesser extent, memory ability and writing speed. The component “Stimulus Orientation, Response Initiation, and Execution” was related to substitution test performance in the sample of children and the sample of older adults but not in the sample of younger adults. Verbal ability was not significantly related to substitution test performance in the two younger samples but was strongly related to substitution performance in the oldest sample. Although females outperformed males on the Symbol Digit Test, males did as well as females on the computerized tasks. Apparently, sex differences in substitution test performance cannot be explained by the components of the test measured here.