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Derived conditional discrimination was evaluated in 2 men with mental retardation whose language was limited to gestural requests. In each conditional-discrimination task, sample stimuli were arbitrary visual forms and comparison stimuli were black squares presented in 2 of the 4 corners of a computer screen. Subjects learned to select 1 position (P1) in the presence of 2 different samples (A1 and 81), and to select a different position (P2) in the presence of another 2 samples (A2 and 82). Next, new position responses (P3 and P4) were taught in the presence of A 1 and A2, respectively. Tests then showed that the 81 and 82 sample stimuli controlled selection of P3 and P4, respectively. The data for 1 subject provided strong evidence for derived conditional responding, while the data for the other were suggestive. This is 1 of a very few studies of derived conditional discrimination in individuals without naming skills.