A study was conducted to observe the peer behavior of 92 black and white sixth graders in a large, urban middle school. A roster rated sociometric study was also conducted, in which the students rated the desirability of each of their classmates as both social and work partners. Both the behavioral and the sociometric study showed a sharp sex division among the students, along with a lesser but significant race division. The results of the study suggest that gender clustering reflects a genuine social barrier and is not merely an incidental product of divergent gender specific interests. The results of the study suggest that greater attention should be given to gender integration as an aspect of the larger goal of social integration. (Author/APM)