In the past three years, we have conducted a programmatic research effort designed to improve our understanding of the social acceptance of mentally retarded children in different school settings. It is our intent to continue and to expand upon the line of research we have begun. Our primary aims will be: 1) To determine how the social acceptability of mentally retarded children among their nonretarded and retarded peers is affected in laboratory and natural situations by their own characteristics, those of their nonretarded peers, and background variables; and 2) To determine if these factors can impeded or reverse the stigmatization of mentally retarded children in laboratory and natural situations. We propose to extend our research in four ways. (1) We will investigate the role that mentally retarded children's conversational skills play (in combination with their other personal characteristics and background variables) in determining their acceptability to nonretarded peers. This investigation of he interactive effects of these characteristics and variables will take place in a laboratory situation. (2) We will attempt to determine whether there is a direct relationship between the attitudes children express in the laboratory and the attitudes and behaviors the same children direct toward mentally retarded peers integrated into their regular classrooms. (3) We will examine the relationship of mentally retarded children's characteristics to their social acceptance in regular classrooms. (4) We will study the behavioral antecedents of mentally retarded children's social acceptance by observing their interactions with nonretarded peers in classroom analog situations. These approaches will help establish the generalizability and ecological validity of our findings.