IN THIS TEXT, WE HAVE EXPLORED many issues that affect people and their well-being throughout the life span. We have examined how human development and behavior and the environment can interact to cause problems for people or bring opportunity for growth. And, of course, the relationship between human behavior and the environment is complex and ever-changing. This is one reason why it is so important for social workers to consider the broader social environment when working with individuals, groups, and communities in the helping process. Similarly, because the interaction between human development and behavior and the social environment is so dynamic and the changes we see in these contexts are so fluid, it is imperative that social workers keep abreast of research and new developments in health, science, politics, education, environment, and a whole host of other realms.