DISPLACEMENT OF LEISURE REINFORCERS BY FOOD DURING PREFERENCE ASSESSMENTS

Identification of reinforcers for individuals with developmental disab ilities is often based on the outcome of preference assessments in whi ch participants make selections from among a variety of items. We dete rmined the extent to which individuals might show a general preference for food items over leisure items during such assessments and whether leisure items that are ''displaced'' by food items might nevertheless function as reinforcers. Arrays consisting of food items only and the n nonfood items only were presented separately to 14 participants and then were ranked to determine preference. The top selections from thes e initial assessments were subsequently combined in a third assessment , and preferences were again established. All but 2 participants showe d a general preference for food items, such that selection of nonfood items in the combined arrays was displaced downward relative to select ion of nonfoods in the nonfood-only arrays. Two of the participants we re exposed to a condition in which a nonfood item was delivered contin gent on the occurrence of an adaptive response, and increased rates of responding by both individuals were observed. Results are discussed i n terms of limitations posed by using only food items as reinforcers a nd the resulting need to take precautionary measures when attempting t o identify nonfood reinforcers.