The rating scale used to assess the motivators of maladaptive behaviors in persons with mental retardation was the Motivation Assessment Scale. In the current study, we validated the factor structure of the scale on a sample of 118 subjects with predominately severe or profound mental retardation. They exhibited deviant behaviors such as self-injurious and tantrum behavior, aggression, and passivity. The results of the factor analysis with varimax rotation validated the assumptions of the developers of the scale that the motivators could be grouped into sensory, escape, attention, and tangible reinforcers. These four subscales are easily interpretable and should continue to provide valuable information.

Perceptions by staff of the classes of reinforcers and aberrant behaviors of a sample of 470 people with predominantly severe or profound mental retardation were explored. Principal components analysis of a 45-item survey suggested eight classes of reinforcers: consumable, verbal-speaker, visual-motor, social, physical-contact, passive-observer, play, and academic reinforcers. Stepwise multiple regression was used to predict five classes of maladaptive behaviors as measured by the Aberrant Behavior Checklist (irritability, lethargy, stereotypy, hyperactivity, and inappropriate speech) from the eight classes of reinforcers. Each class of psychopathology was related to a unique set of predictors. All classes of psychopathology could be predicted by staff perceptions of underresponsiveness to social reinforcers and overresponsiveness to consumable reinforcers. The findings of organized structures of reinforcers and their covariation with pathological behaviors have implications for research and intervention as well as theoretical value in defining aberrant behaviors in people with mental retardation.