Using the person-and-environment approach to analyze all aspects of human development, this book discusses the biological, psychological, social, and cultural influences that shape the functioning of individuals, families, communities, and organizations, and relates how these collectives affect development over the life course. It also takes into account the expected and unexpected stresses and challenges that can influence development. Reflecting the guidelines set forth by the National Association of Social Workers and the Council on Social Work Education, this book enables the social worker, whether student or professional, to build a theoretical foundation for work in the field. This new edition provides the latest theoretical developments and research findings in the social, behaviourial, and biological sciences.