Three models of behavior are used to define criminal behavior. The psycho-social model emphasizes a nonphysical environment. The stimulus-response model focuses on environmental factors to the exclusion of all other input factors. The biosocial learning theory model emphasizes interactions between organisms and the environment. The physical environment has implications for both sociology (as the arena in which human interactions take place) and for psychology (as a stimulus for human learning and response). Interactions between the organisms and their environment can occur in several forms: the organism has the capacity to change the environment, and the environment effects changes upon the organism. The physical environment has been largely ignored in ecological studies of crime; however, small area studies have indicated that environmental factors play a role in the incidence of crime. Understanding crime in relation to the physical environment requires an interdisciplinary effort using the efforts of urban geographers and planners, sociologists, psychologists, and criminologists. Social area analysis of crime has failed to develop useful remedies. Either new solutions to this problem must be developed using a bioecological model of behavior, or the current trend to harsher punishments as a deterrent will continue. Charts and about 70 references are included.