ASSESSMENT OF STEREOTYPIC AND SELF-INJURIOUS-BEHAVIOR AS ADJUNCTIVE RESPONSES

Certain responses of both humans and nonhumans appear to be maintained indirectly by intermittent reinforcement schedules and have been refe rred to collectively as adjunctive behavior. Although basic research h as examined adjunctive behavior extensively, relatively few studies ha ve been conducted with humans, particularly those with developmental d isabilities who often engage in frequent and varied stereotypic behavi or. This study assessed possible adjunctive characteristics of self-in jurious and stereotypic behaviors using a multielement design containi ng two types of control conditions. Four subjects who engaged in both self-injurious behavior and stereotypy participated after variables ma intaining their self-injury were identified via functional analyses. E ach day, subjects were exposed to three 15-min sessions in random orde r: (a) noncontingent presentation of food on a fixed-time schedule (e. g., FT 30 s), (b) a massed-reinforcement (food) control and (c) a no-r einforcement control. A variety of fixed-time schedules were examined during different experimental phases. Results of this preliminary stud y suggested that self-injury was not induced by intermittent reinforce ment schedules, whereas the stereotypic behavior of some individuals s howed characteristics of adjunctive behavior. The importance of resear ch on adjunctive behavior and suggestions for future studies are discu ssed.