A group of 42 adult male and female retardates, classified as mildly retarded and living in a group residence facility, participated in a study of the effects of increased behavioral competencies on the personality constructs of locus of control and self-esteem. A series of individualized prescriptive programs was developed for the participants which included social approval and token allocation contingent upon successful attainment of requisite levels of target behavior efficiency. The American Association on Mental Deficiency's Adaptive Behavior Scale, the Coopersmith Self-Esteem Inventory, and the Adult Nowicki-Strickland Locus of Control Scale were administered prior to the initiation of the programs, at the conclusion of the two-month implementation period, and at follow-up assessment intervals of three and nine months. At the end of the program training period, all residents exhibited improvement in specific behavioral competencies and in self-esteem, as well as change in locus of control orientation from an external orientation to a moderately internal one. Three and nine-month follow-up assessments revealed negligible changes in the improved self-esteem and behavioral competency results, and only a slight shift in locus of control back to the direction of externality.