The continuity theory of aging states that “in making adaptive choices middle‐aged and older adults attempt to preserve and maintain existing psychological and social patterns by applying familiar knowledge, skills, and strategies.” George Maddox was the first researcher to use the idea of continuity to describe the behavior of aging individuals in 1968 when he observed that people tended to engage in similar activities and to continue familiar lifestyle patterns as they age; however, the continuity theory of aging was not introduced until 1989. Robert Atchley is credited with the development of this theory. Continuity theory takes a life course perspective in which the aging process is shaped by history, culture, and social constructs. According to this theory, continuity in aging is seen as a dynamic and evolutionary developmental process in which individuals grow, adapt, and change; however, these changes are consistent with the person's underlying ideology and past experiences. The degree of an individual's life satisfaction is linked to how consistent their current activities are with their past experiences and self‐perception.
Internal and External Continuity
Atchley describes continuity in terms of both internal and external continuity and describes how aging individuals are motivated toward maintaining both a self‐concept and a social pattern that is consistent with the person's history and their perception of themselves and their social environment. Internal continuity refers to a persistence of an individual's unique internal structure over time, which is comprised of a person's self‐perception, belief system, goals, and past experiences and would include their skills, ideas, personal preferences, and temperament. Maintenance of internal continuity is driven by an individual's desire for predictability in life that provides a sense of security and stability for the individual. Maintenance of self‐esteem and self‐identity is also an important driver for internal continuity. As people are faced with change they adapt themselves by adding to their existing perception of who they are and by using their existing identity to help provide the framework for making future decisions.
External continuity is dependent on a remembered physical and social environment that includes a person's relationships, social roles, and activities. A person is motivated toward external continuity by their desire to be consistent with the expectations of others that are based on the individuals past roles and behaviors. Following familiar patterns of activity and social interaction also affords a certain level of predictability and can aid in decision‐making and adapting to change. The ability to consult a set of criteria and set of resources based on past experiences, internal, and external structures is instrumental in allowing aging people to successfully interpret physical, mental, social, and environmental changes and integrate change into their lives in an adaptive manner without causing disruption.
Limitations of Continuity Theory
A limitation of continuity theory is its focus on people who are aging “normally”; in this context, “normally” aging people are considered to be those without disabling conditions who are capable of meeting their needs both economically and physically. “Normally” aging adults have meaningful, productive lives and have established social networks. This theory may not be suitable for those adults who are undergoing “pathological” aging. Since these adults may be disabled or poor or have lack of social networks, the ability to maintain external continuity may be limited by their life situation, although internal continuity may be unaffected. In cases where people have illnesses affecting cognition or memory, internal and external continuities are likely to be affected. Maintenance of internal continuity is dependent on a person having knowledge of himself or a self‐identity and personal history that they can draw upon to aid them in decision‐making. External continuity also depends on memory, as it relies on the person having a familiar set of relationships, environments, and activities.
As with most individual characteristics, continuity exists on a continuum from too little continuity (discontinuity) to too much continuity, with an optimum level of continuity in between. Too little continuity can be undesirable for aging individual because of the lack of predictability that may make life seem out of control or chaotic. If severe enough, discontinuity can cause individuals to experience anxiety or depression secondary to their inability to predict the outcome of any given situation. Discontinuity that causes a person to lose a role in which they strongly identify (e.g., “teacher,” “mentor,” and “boss”) or an environmental change (e.g., moving to a retirement village, skilled nursing facility, or with children) leading to the loss of familiarity with their environment can erode a person's self‐identity and cause significant stress to the individual as well. Residing at the opposite end of the continuity spectrum can also be undesirable in that too much continuity can cause a person to lack any type of stimulation or need to adapt to change, which can make life monotonous and potentially unfulfilling. While using maintenance of continuity as a coping and adaptive mechanism can often aid the aging person in responding to life changes, an overemphasis on continuity can be maladaptive as well. For example, a person who refuses to seek necessary medical treatment in a new environment or away from familiar doctors or relatives in an attempt to maintain external continuity when faced with disease.
Public Health Perspective
It is essential for health practitioners and public health professionals to have an understanding of continuity theory and how individuals are motivated toward preserving internal and external continuity. Approaching individual change from the perspective of the patient and incorporating their perceptions of themselves and their personal history into the decision‐making process can aid health providers and patients in making decisions that will allow the patient to maintain optimal continuity in their lives. Aiding the patient in making sense of their situation and to seeing how change can be incorporated into their lives without causing discontinuity or disruption can reduce the stress on the individual patient, strengthen the provider–patient relationship, and increase the likelihood of patient adherence to recommendations. This cooperative and holistic approach is also a mechanism for showing respect and regard for the individual patient and their unique personality and set of skills, desires, and beliefs, allowing providers to offer the most patient specific and clinically appropriate recommendations to their patients.