Peer presence and the emergence of conditioned reinforcement from observation

We examined the effects of peer presence on the conditioning of new reinforcers via observation. At the outset, strings and toothpicks did not reinforce maintenance or acquisition responses for 3 preschoolers with and without developmental delays. In the first intervention, the stimuli were placed in a cup in front of an empty chair next to the participant, and the participant was denied access to those stimuli. The second intervention was identical to the first, except that a peer was present. Postintervention tests revealed that only the peer intervention was successful in conditioning neutral stimuli as reinforcers for both maintenance and acquisition responses for all 3 participants. The presence of a peer appears to facilitate the conditioning of reinforcers by observation.