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 ages 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. The authors wish to thank Betty Shuttleworth for her assistance with the recruitment of elderly subjects, Sue Cornfield for her role in the recruitment and screening of the initial sample of elderly subjects, and Sarah Radloff for conducting the statistical analyses.