Analyzing the stimulus properties of objects used in stereotyped behavior.

Ten severely retarded children who engaged in object stereotypies were observed during 10, 1-hour sessions in various contexts of their living and school environments. The percentage of object stereotypies performed and the nature of the objects manipulated were described. For the children as a group, context did not affect the level of object stereotypies, but other stereotypies were performed most often during music sessions. In Study 2 the objects manipulated in a stereotyped manner were presented to six people who were asked to describe the physical dimensions of the object when it was moved. Judges found that most children appeared to respond to flexibility, whereas some children appeared to respond to other feedback. Study 3 was designed to validate the dimensions selected by the judges. Each dimension agreed on by five of the judges in Study 2 was used to construct sets of five objects that varied with respect to that dimension. The children were presented with the set of objects and differential manipulation along the dimension was assessed. The judges' selections were partially validated.