Psychologist Daniel Levinson developed a comprehensive theory of adult development, referred to as the Seasons of Life theory, which identified stages and growth that occur well into the adult years.
His theory is comprised of sequence-like stages. Each stage is shaped by an event or action that leads into the next stage. The stages are:
1. Early Adult Transition (Age 17-22). This is the stage in which a person leaves adolescence and begins to make choices about adult life. These include choosing to go to college or enter the workforce, choosing to enter a serious relationship, and choosing to leave home.
2. Entering the Adult World (Age 22-28). This is the stage in which a person makes more concrete decisions regarding their occupation, friendships, values, and lifestyles.
3. Age 30 Transitions (Age 28-33). In this stage, there are often lifestyle changes that could be mild or more severe. For example, marriage or having children impact one's lifestyle, and these changes have differing consequences on how a person develops depending on how they embrace the event.
4. Settling Down (Age 33-40). In this stage, one often begins to establish a routine, makes progress on goals for the future, and begins behaving like an adult. People in this stage are often parents or have more responsibilities.
5. Mid-Life Transition (Age 40-45). This time period is sometimes one of crisis. A person begins to evaluate his or her life. Values may change, and how society views these people may change also. Some people make drastic life changes, such as divorce or a career change. At this point, people begin thinking about death and begin to think about leaving a legacy.
6. Entering Middle Adulthood (Age 45-50). In this stage, choices must be made about the future and possibly retirement. People begin to commit to new tasks and continue to think about the legacy they are leaving.
7. Late Adulthood (Age 60+). In this stage, one begins to reflect...