One of 52 theoretical papers on school crime and its relation to poverty, this chapter examines the human ecology of school crime. It explores the relationship between the structure of the school as a social system and the dynamics of student and staff behavior. The central thesis is that schools become "out of control" when they are large and serve academically marginal or socially alienated students. The potency of the school as a support system for prosocial behavior is examined in the light of evidence linking school size to depersonalization of student-staff relationships, a shift toward impersonal methods of social control, and noncontingent feedback on both prosocial and antisocial behavior. (Author/MLF)