The construct validity of the Category Test: Is it a measure of reasoning or intelligence?

Although the Category Test (W. C. Halstead, 1947) is generally described as a measure of abstract reasoning, determination of its construct validity has been difficult given methodological inconsistencies of previous studies. It has been suggested that the Category Test measures intelligence (G. J. Boyle, 1988), although others suggest it measures distinct reasoning processes (M. D. Kelly, D. K. Kundert, & R. S. Dean, 1992; K. Perrine, 1993). This study investigated the construct validity of the Category Test for 308 participants with heterogeneous cognitive dysfunction. A factor analysis using measures of reasoning (Category subtests), intelligence (Wechsler Adult Intelligence Scale-Revised; D. Wechsler, 1981), memory (Wechsler Memory Scale-Revised; D. Wechsler, 1987), and other problem solving abilities (Trail Making Test; Army Individual Test Battery, 1944; Tactual Performance Test; W. C. Halstead, 1947) indicated the Category subtests to load on 3 factors distinct from intelligence (and other neuropsychological measures), labeled as follows: Symbol Recognition/ Counting (Subtests 1 and 2); Spatial Position Reasoning (Subtests 3, 4, and 7); and Proportional Reasoning (Subtests 5 and 6). Clinical implications are discussed.