LAUSR

Abstract Perspective-taking has for many years attracted considerable research attention in the mainstream cognitive developmental literature, under the rubric of Theory of Mind. Recently, the modern behavioral approach to human language and cognition known as Relational Frame Theory suggests that perspective-taking is a form of generalized operant responding involving deictic relations, such as I versus YOU, HERE versus THERE and NOW versus THEN, with different levels of relational complexity. People with intellectual disability often lack perspective-taking, and this deficit can detrimentally impact the quality of their social interactions. The current study is the first to train an adult with Down syndrome in deictic relational responding. The participant was exposed to multiple exemplars consisting of interactive tasks and feedback aimed at training reversed I-YOU, HERE-THERE and NOW-THEN deictic relations. The participant reached mastery on I-YOU, HERE-THERE and NOW-THENreversed tasks. In line with previous research in the area of deictic relations, more training trials on NOW-THEN relations was required for the participant to meet criterion than I-YOU or HERE-THERE relations. Implications for the use of training deictic relations with individuals diagnosed with Down syndrome are discussed.