A reevaluation of stimulus overselectivity: restricted stimulus control or stimulus control hierarchies.

Stimulus overselectivity, previously described as restricted stimulus control, was examined in preschool children. Twenty-seven subjects, after being trained to respond to a two-component auditory stimulus (S+) and not to respond to a different two-component auditory stimulus (S-), were tested to determine which stimulus elements of the complexes exerted control. Subjects that met the operational definition of overselectivity were found to have exhibited a hierarchy of stimulus control. What differentiated the subjects who would not be labeled "overselective" from those who would be was the placement of S+ and S- elements within the hierarchy, not that one type of subject had restricted stimulus control and another did not. The results indicate that the current conception of stimulus overselectivity may require revision. Treatment and research implications are discussed.