❍ This theory was first proposed by Robert Atchley in 1971, through his article 'Retirement and Leisure Participation: Continuity or Crisis?', published in the journal The Gerontologist. He later published another article 'A Continuity Theory of Normal Aging' in the same journal, where he further developed his previously proposed theory. He expanded it so as to cover a wide range of internal and external constructs related to an individual's aging. This theory was further strengthened and refined by him in his book 'Continuity and Adaptation in Aging: Creating Positive Experiences'. ❍ The basic premise that, as an adult ages and becomes a senior citizen in society, he/she tends to maintain their unique mentality, behavior, and physical and social activities, as they did in the past when they were younger. This theory is considered to be a micro-level theory, as it concerns individuals rather than a broad group. In terms of functionality, it is deemed to have a constructive nature, since it tries to establish a state of equilibrium between the individuals and the society. ❍ The theory provides a fundamental framework to be able to understand how senior citizens employ their inherent abilities, skills, and gained experiences to adapt and adjust to the changes brought on due to aging. It is used to make the transition from a working adult to a retired adult, a smooth one. It allows people to be able to make future decisions based on a stable foundation of their decisions and behavior in the past. As mentioned earlier, the theory also deals with the internal and external nature of continuity with respect to aging. It claims that along with the social continuity of activities, behavior, and relationships, internal continuity of ideas, experiences, skills, etc., and external continuity of activities, social roles, relationships, lifestyle, etc., are maintained. These maintained aspects are utilized by senior citizens in order to adapt to the new and changing environment, and eventually adopt it. ❍ For example:

• A young extrovert will tend to remain extroverted in his/her later years, causing them to continue being social and outgoing.
• An introverted and withdrawn person, similarly, will most likely be a private person in his/her old age as well.
• Similarly, other traits such as physically active, avid reader, dancing, singing, etc., will also be maintained in individuals, despite their progressing age.