Various models and theories of adult development exist but they are more assumptions about development than theories. The most popular age and stage theories have lost favor to contextual theories that put more emphasis on interaction with the environment. It has also become recognized that adults are a diverse group and do not follow universal stages of development. The usefulness of chronological age is also questionable as it does not tell us much about any particular person. Instead, we have to know their concerns and the events they are dealing with, and their dreams and aspirations.