Work response of mildly mentally retarded adults to self- versus external regulation as a function of motivational orientation.

The Picture Motivation Scale was administered to 144 mildly mentally retarded adults from a community-based intermediate care facility. Those in the top and bottom quartiles on intrinsic motivation were classified as either relatively task intrinsically motivated or task extrinsically motivated and were assigned to behavior regulation conditions: self-regulated reinforcement, externally imposed reinforcement, or control. All subjects were given a work task consisting of placing washers into successive compartments of a container, with subjects in the external-reinforcement condition yoked to those in the self-regulation condition with respect to work goal and number of tokens received for their work. Across conditions intrinsically motivated subjects worked harder than did extrinsically motivated subjects; all of them worked harder under conditions of regulation of reinforcement matched to their motivational orientation (i.e., intrinsically motivated subjects under self-regulation, extrinsically motivated subjects under externally imposed reinforcement) than under the contrary condition. When not rewarded, intrinsically motivated subjects showed more sustained performance than did extrinsically motivated subjects. The importance of matching self-regulation expectations to individual differences in motivational orientation of retarded persons being prepared for relatively independent living was discussed.