This paper examines theories of human development within the context of the models presented by the schools of cognitive learning, behavioralism, psychoanalysis, and humanistic views of growth. Stress is placed on the stages of human development that provides a means of better meeting the needs of students ages 10-14 in the middle school milieu. The basic premise of the middle school concept, especially with regard to appropriate curriculum, learning skills, teaching strategies, guidance, and the provision of learning experiences is based on the nature of the child. Teacher educators who believe in the middle school concept have advanced persistently an interrelated set of principles or key characteristics that experience has demonstrated most nearly meet the developmental needs of students in grades 6-8. The unique educational goals and learning environment required for this population are considered in light of information provided by human development theorists. All of the theories have their own strengths and weaknesses, their own possible application, within the organization of the middle school surroundings. Each suggests instructional and guidance processes most apt to enhance learning and adjustment during a period of particular turmoil and transition. Comparisons, contrasts, and criticisms are expressed on models established by such notables as Piaget, Erickson, Bruner, Maslow, Freud, and Rogers. When taken as a body of knowledge, each model affords a part of the entire panorama of human development and addresses the middle school teacher demonstrating the vast impact on middle school education. Contains 29 references. (Author/DK)