This paper, one of a group prepared by the Classroom Interaction Project of the University of Missouri's Center of Social Behavior (see related documents AL 002 750-752), is organized into two parts. The first section, a presentation of results of research into the sociolinguistic distribution of syntactic structures in black and white classrooms, is divided into three categories: those dealing with grade level differences between (1) black and white pupils, (2) teachers of black pupils and teachers of white pupils, and (3) the total sets of teachers and pupils. Findings did not support the two major hypotheses that (1) white pupils use complex language more frequently than black pupils, and (2) complexity of language increases with grade level. It was found rather that black and white pupils in the sample were in different language development cycles, in which whites attained maximum use of complex structures sooner than blacks but where blacks used more complex structures once their peak of development had been reached. It was also found that the classroom language of the teacher tended to reflect that of the pupils. The second section of the paper discusses the implications of the research for language research as well as for education. (FWB)