Taking account of age-related differences on Digit Symbol and Incidental Recall for diagnostic purposes.

The purpose of the present study was to develop age-related normative data on the WAIS Digit Symbol subtest, and a short form of the Digit Symbol Incidental Recall test, for a nonclinical population of English-speaking South Africans with a relatively high level of education. The tests were administered to 131 individuals between the age of 20 and 89 years with at least 10 years of education (mean = 14.93 years; range = 10-22 years). A significant age effect was found on both tests. Preliminary normative data across five age groups (20-39, 40-59, 60-69, 70-79, and 80-89 years) are presented, and are considered diagnostically useful for clinical practice on persons of above-average intelligence. The utility of the short form of the recall test is confirmed and advocated particularly for work on older age groups.