The paper reviews literature on placement of mentally retarded students and the effects on adaptive behavior. Research cites the importance of social skills, intervention to benefit from integrated placement and touches upon the role of nonhandicapped peer trainers. Among findings noted are an increase in constructive peer interactions resulting from mainstreamed placements, imitation of modeled behavior by severely retarded children in mainstreamed settings, and increases in positive social interaction along with decreases in inappropriate behavior. The paper concludes that such benefits tend to be the result of using age appropriate nonhandciapped peer models. A three-page bibliography concludes the paper. (CL)