UMMS Affiliation

Shriver Center

Publication Date


Document Type



Discrimination Learning; Symbolism; Developmental Disabilities; Mental Retardation; Child Development Disorders, Pervasive


Mental and Social Health | Neuroscience and Neurobiology | Psychiatry and Psychology


This paper reports on "exclusion," a phenomenon demonstrated when a participant views an array of comparison stimuli, all but one of which has been defined in relation to a spoken sample stimulus (most often a dictated name). When a new undefined sample is spoken, participants immediately select the undefined comparison item without explicit training to do so. Exclusion has attracted interest from behavior analysts interested in analyzing emergent behavior and/or exploiting the potential of the procedure for teaching new behavior to persons with severe mental retardation. The importance of the research area has grown in recent years, as the phenomenon has been recognized also by researchers interested in the development of child language and comparative cognition. Since the first studies of exclusion, in the mid-1970s, we have learned much about the populations in which it appears, the types of stimuli that can enter into exclusion, and the contexts that affect performances. Yet a fundamental question remains unanswered: What is the origin of exclusion performance? Why do virtually all individuals demonstrate exclusion on the very first opportunity? A research group from the Shriver Center for Mental Retardation (USA) have recently developed a series of methodologically intricate, sometimes interconnected single-subject designs to answer these questions. This paper will describe work that has been completed thus far with individuals with severe mental retardation and a comparison group of typically developing children.


Wilkinson, KM; de Souza, DG.; McIlvane, WJ. As origens da exclusão (origins of exclusion). Temas Em Psicologia 2000, vol.8, n.2, pp. 195-203. ISSN 1413-389X. Link to article on publisher's website

Journal/Book/Conference Title

Temas Em Psicologia


Article is in Portuguese with an abstract in English.



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