Since the publication of the first edition of Human Behavior in the Social Environment, several generations of students have successfully used this classic text, which takes a social systems approach to human behavior. Completely revised and updated, this fifth edition shows a full sensitivity to the diverse constituencies of the human services. It reflects awareness of the role of varied cultural and ethnic features within the social environment it explores, and of the importance of the lengthened life cycle. It responds to our understanding of human behavior and to the needs of students and instructors as these have developed since the publication of the previous edition. For the first time, an ancillary diskette to assist in teaching the systems approach is available on request for instructors who have adopted this new edition.