• stereotypy;
  • self-injury;
  • negative reinforcement;
  • positive reinforcement;
  • self-stimulation

Stereotypic and self-injurious behaviors are common forms of maladaptive responding demonstrated by severely handicapped persons. Various review papers suggest that no single treatment procedure is universally effective. Although there may be many reasons for this finding, one could be that people engage in these behaviors for various reasons, and that procedures that are incompatible with the cause of the behavior are unlikely to be effective. These studies also suggest many hypotheses for the development and maintenance of these behaviors, three of which are the self-stimulation, positive reinforcement, and negative reinforcement hypotheses. The purpose of this paper was to determine whether one of these hypotheses could be matched to the cause of the behavior and used as an effective treatment procedure. We therefore compared one hypothesis with one other for 3 subjects in a three-phase study. During baseline, data were taken in two classrooms for each subject, and a judgment was made about the hypothesis most likely to be related to the cause of the behavior. During the second phase, a treatment based on that hypothesis was used in one classroom, and a treatment based on another hypothesis was used in the second classroom. During the third phase, the treatment that was most effective in the second phase was used in both classrooms. Results showed that a successful treatment program can be developed on an hypothesis of why the behavior occurred during baseline. Results are discussed in terms of supporting the argument that treatment programs should be based on a functional analysis of the behavior in its environmental context.