The few studies concentrating on adult age changes in discrimination shift behavior have reported that the performance of elderly adults on such tasks is inferior to that of younger adults and, in fact, similar to that of children. To determine whether verbal labeling, which has facilitated the performance of young children, would also reduce age decrements in the discrimination shift behavior of elderly adults, 32 college students and 26 older adults were randomly assigned to one of two optional shift conditions. In the label condition, subjects were encouraged to verbalize the value of the dimension made relevant by reinforcement in the initial learning phase. In the no label condition, subjects proceeded as usual, i.e., without verbalizing the correct values of the relevant dimension. Analyses of results indicated an absence of age-related differences in the number of reversal shift choices; however, older adults made reversal shifts less often than did younger adults. Although older adults' initial learning performance on the optional shift task was facilitated by labeling, their shift discrimination performance was actually impeded by labeling. (Author/JAC)