Family therapy suggests a reformulation of concept and method in studying the family and individual development: to regard the family as an organized system and the individual as a contributing member, part of the process that creates and maintains the patterns that regulate behavior. In this review, the theories and clinical experiences of family therapists are regarded as a resource for developmental psychology, and particular attention is paid to those aspects that challenge traditional formulations in the developmental field. The review focuses on systems theory as the paradigm underlying family therapy and considers the implications of this framework for conceptions of the individual, the study of parent-child interaction, and new research formulations and areas of study. It also considers trends in the developmental field that move toward such formulations.