Jeffrey Arnett, a psychologist and professor at Clark University in Massachusetts, studied the development of adults and argues that there is a new and distinct period of development in between adolescence and adulthood. This stage, which he calls "emerging adulthood," occurs between the ages of 18 and 25. Arnett articulates five distinct features that are unique to this period of development. This stage is an age of identity exploration, instability, self - focus, feeling in between, and an age of possibilities. Arnett describes these individuals as able to take some responsibility for their lives, but still not completely feeling like an adult. Arnett describes individuals in this stage of development as deciding who they are and what they want out of life. Often times they change residences because they are getting higher education and are no longer tied to the routine of living with their parents. Arnett says these individuals can essentially go where they want when they want. Arnett also says that "optimism reigns." People in this stage of life are confident that they can make a better life for themselves than their parents had and can have deeper, longer lasting relationships.