Displacement of One Stimulus Class Over Another Stimulus Class: A Systematic Replication
Previous researchers have found that individuals with intellectual and developmental disabilities tend to prefer edible over leisure stimuli and that leisure stimuli generally function as less effective reinforcers than edible stimuli, regardless of the preference patterns observed during a combined-class multiple-stimulus without replacement (MSWO) assessment. However, researchers have often arbitrarily selected items to include in these preference assessments and have not investigated this phenomenon with typically developing children. In Study 1, we evaluated the preference for leisure and edible stimuli in a combined-class MSWO assessment with 15 typically developing children. Five of 15 participants preferred edible stimuli over leisure stimuli, 3 of 15 participants preferred leisure stimuli over edible stimuli, and the remaining seven of 15 participants did not prefer one stimulus class over another. In Study 2, we compared the reinforcer potency of displaced stimuli and the stimuli that displaced them with 7 of 8 participants who showed displacement of one stimulus class over the other. Four of 7 participants allocated more responding to the free-operant task associated with the top-ranked stimulus identified in the combined-class MSWO, while 3 of 7 participants showed no differences in responding to the free-operant task regardless of ranking of the reinforcer delivered.