Theories of Aging
Biologic
Concerned with answering basic questions regarding physiologic processes that occur in all
living organisms over time (Hayflick, 1996).
Sociologic
Focused on the roles and relationships within which individuals engage in later life (Hogstel,
1995).
Psychological
Influenced by both biology and sociology; addresses how a person responds to the tasks of his or
her age.
Nursing
Helps to describe and explain phenomena; predicts and prescribes nursing interventions for the
range of different situations encountered in the profession of nursing (Garcia & Maya, 2015).
Moral/Spiritual
Examines how an individual seeks to explain and validate his or her existence (Edelman &
Mandle, 2003).
, Biologic theories are concerned with answering basic questions regarding the physiologic
processes that occur in all living organisms as they chronologically age. These age-related
changes occur independent of any external or pathologic influence.
Cross-linkage theory
The cross-linkage theory of aging hypothesizes that with age, some proteins become increasingly
cross-linked or enmeshed and may impede metabolic processes by obstructing the passage of
nutrients and wastes between the intracellular and extracellular compartments.
Cross-linkage theory proposes that as a person ages and the immune system becomes less
efficient, the body’s defense mechanism cannot remove the cross-linking agent before it becomes
securely established. Cross-linkage has been proposed as a primary cause of arteriosclerosis,
decrease in the efficiency of the immune system, and the loss of elasticity often seen in older
adult skin.
Free radicals
Free radicals are byproducts of fundamental metabolic activities within the body.
Hayflick Limit Theory