THEORIES OF AGING
Based on information in: Madison,
H.E. (2002).“Theories of Aging”. In
Lueckenotte, A.G. (ed), Gerontologic
Nursing. St. Louis: Mosby.
Theories of Aging:
attempt to explain the phenomenon of
aging as it occurs over the lifespan
– aging is viewed as a total process that begins
at conception
– senescence: a change in the behavior of an
organism with age leading to a decreased
power of survival and adjustment
Theories of Aging: Types
Biologic
Sociologic
Psychologic
Moral/Spiritual
Biologic Theories:
Concerned with answering basic questions
regarding the physiological processes that
occur in all living organisms as they
chronologically age
Foci of Biologic Theories
Explanations of:
– 1) deleterious effects leading to decreasing
function of the organism
– 2) gradually occurring age-related changes that
are progressive over time
– 3) intrinsic changes that can affect all member
of a species because of chronologic age
ALSO:
– all organs in any one organism do not age at
the same rate
– any single organ does not necessarily age at
the same rate in difference individuals of the
same species
Biologic Theories: Divisions
Stochastic: Explain aging as events that
occur randomly and accumulate over time
Nonstochastic: View aging as certain
predetermined, timed phenomena
Stochastic Theories
Error Theory
Free Radical Theory
Cross-Linkage Theory
Wear & Tear Theory
Error Theory
Originally proposed in 1963
Basis: 1)errors can occur in the
transcription in any step of the protein
synthesis of DNA
– 2) error causes the reproduction of an enzyme
or protein that is not an exact copy
– 3) As transcription errors to occur, the end
product would not even resemble the original
cell, thereby compromising its functional
ability
Error, cont’d
More recently the theory has not been
supported by research
– not all aged cells contain altered or
misspecified proteins
– nor is aging automatically or necessarily
accelerated if misspecified proteins or
enzymes are introduced into a cell
Free Radical Theory
Free radicals are byproducts of
metabolism--can increase as a result of
environmental pollutants
When they accumulate, they damage cell
membrane, decreasing its efficiency
The body produces antioxidants that
scavenge the free radicals
Free Rads, cont’d
In animal studies, administration of
antioxidants postpones the appearance of
diseases such as cardiovascular disease and
CA
Free radicals are also implicated in the
development of plaques associated with
Alzheimer’s
Cross-Linkage Theory
Some proteins in the body become cross-
linked, thereby not allowing for normal
metabolic activities
Waste products accumulate
Result: tissues do not function at optimal
efficiency
C-L Theory, cont’d
Some research supports a combination of
exercise and dietary restrictions in helping
to inhibit the cross-linkage process
Wear & Tear Theory
Proposed first in 1882
Cells simply wear out over time because of
continued use--rather like a machine
Would seem to be refuted by the fact that
exercise in OA’s actually makes them
MORE functional, not less
Nonstochastic Theories:
Programmed Theory
Immunity Theory
Programmed (Hayflick Limit)
Theory
Based on lab experiments on fetal
fibroblastic cells and their reproductive
capabilities in 1961
Cells can only reproduce themselves a
limited number of times.
Life expectancies are seen as
preprogrammed within a species-specific
range
Immunity Theory
Immunosenescence: Age-related functional
diminution of the immune system
Lower rate of T-lymphocyte (“killer cells”)
proliferation in response to a stimulus
& therefore a decrease in the body’s
defense against foreign pathogens
Immunity, cont’d
Change include a decrease in humoral
immune response, often predisposing older
adults to:
– 1)decreased resistance to a tumor cell
challenge and the development of cancer
– 2) decreased ability to initiate the immune
process and mobilize defenses in aggressively
attaching pathogens
– 3) increased susceptibility to auto-immune
diseases
EMERGING THEORIES OF
AGING
Neuroendocrine Control (Pacemaker)
Theory
Metabolic Theory/Caloric Restriction
DNA-Related Research
Neuroendocrine Control
“…examines the interrelated role of the
neurologic and endocrine systems over the
life-span of an individual”. (p. 24)
there is a decline, or even cessation, in
many of the components of the
neuroendocrine system over the lifespan
Neuro, cont’d
Research has shown
– 1) the female reproductive system is controlled
by the hypothalamus. What are the
mechanisms that trigger changes?
– 2) adrenal glands’ DHEA hormone
– 3) melatonin (from pineal gland)--a regulator
of biologic rhythms and a powerful
antioxidant. Declines sharply from just after
puberty
Metobolic Theory of Aging
(Caloric Restriction)
“…proposes that all organisms have a
finite amount of metabolic lifetime and that
organisms with a higher metabolic rate
have a shorter lifespan”. (p. 24)
Rodent-based research has demonstrated
that caloric restriction increases the
lifespan and delays the onset of agedependent diseases
DNA-Related Research
Major Developments:
– Mapping the human genome (“…there may be
as many as 200 genes responsible for
contolling aging in humans”)
– Discovery of telomeres
SOCIOLOGIC THEORIES OF
AGING
Disengagement Theory
Activity/Developmental Task Theory
Continuity Theory
Age Stratification Theory
Person-Environment Fit Theory
Changing FOCUS of Sociological
considerations of aging:
– 60’s focus on losses and adaptation to them
– 70’s broader global, societal, and structural
factors influencing lives of OA’s
– 80’s-90’s exploration of interrelationships
between OA’s and their physical, political,
environmental & socioeconomic mileau
Disengagement Theory
Cumming & Henry--1961
Aging seen as a developmental task in and
of itself, with its own norms & appropriate
patterns of behavior
“appropriate” behavior patterns involved a
mutual agreement between OA’s and
society on a reciprocal withdrawal.
No longer supported
Activity Theory (Developmental
Task Theory)
Havighurst, Neugarten, Tobin ~1963
“Activity is viewed by this theory as
necessary to maintain a person’s life
satisfaction and a positive self-concept”.
(p.27)
Activity, cont’d
Theory based on assumptions:
– 1) it’s better to be active than inactive
– 2) it is better to be happy than unhappy
– 3) an older individual is the best judge of his
or her own success in achieving the first two
assumptions
Continuity Theory
How a person has been throughout life is
how that person will continue through the
remainder of life
Old age is not a separate phase of life, but
rather a continuation and thus an integral
component
Age Stratification Theory
Riley--1985
Society consists of groups of cohorts that
age collectively
The people & Roles in these cohorts
change & influence each other, as does
society at large
Thus, there is a high degree of
interdependence between older adults &
society
Person-Environment Fit Theory
Lawton, 1982
Individuals have personal competencies
that assist in dealing with the environment:
–
–
–
–
ego strength
level of motor skills
individual biologic health
cognitive & sensory-perceptual capacities
P-E Fit, cont’d
As a person ages, there may be changes in
competencies & these changes alter the
ability to interrelate with the environment
Significant implications in a society that is
characterized by constantly changing
technology
PSYCHOLOGIC THEORIES
OF AGING
Maslow’s Hierarchy of Human Needs
Jung’s Theory of Individualism
Erikson’s Eight Stages of Life
Peck’s Expansion of Erikson’s Theory
Selective Optimization with Compensation
Maslow’s Hierarchy of Human
Needs
Maslow--1954
“…each individual has an innate internal
hierarchy of needs that motivates all
human behaviors”. (p. 29
depicted as a pyramid; the ideal is to
achieve self-actualization, having met all
the “lower” level needs successful
“Maslow’s fully developed, self-actualized
person displays high levels of all of the
following characteristics: perception of
reality; acceptance of self, others, and
nature; spontaneity; problem-solving
ability; self-direction; detachment and the
desire for primacy; freshness of peak
experiences; identification with other
human beings;…….
…satisfying and changing relationships
with other people; a democratic character
structure; creativity; and a sense of values.
Only about 1% of us are truly ideal self-
actualized persons
Jung’s Theory of Individualism
Carl Jung--1960
origins are Freudian
Self-realization is the goal of personality
development
as individual ages, each is capable of
transforming into a more spiritual being
Erikson’s Eight Stages of Life
1993
Stages throughout the life course. Each
represents a crisis to be resolved.
For OA’s:
– 40 to 65 (middle adulthood): generativity
versus self-absorption or stagnation
– 65 to death (older adulthood): ego integrity
versus despair
Erikson, cont’d
“Self-absorbed adults will be preoccupied
with their personal well-being and material
gains. Preoccupation with self leads to
stagnation of life”
“Unsuccessful resolution of the last crisis
may result in a sense of despair in which
individuals view life as a series of
misfortunes, disappointments, and
failures”. (p.30)
Peck’s Expansion of Erikson’s
Theory
Erikson’s last two stages are expanded to 7
The final three of the developmental tasks
for old age:
– ego differentiation versus work role
preoccupation
– body transcendence versus body
preoccupation
– ego transcendence versus ego preoccupation
Selective Optimization with
Compensation
Baltes--1987
Individuals develop strategies to manage
losses of function that occur over time
Selective Optimization, cont’d
3 Interacting Elements:
– selection: increasing restriction of one’s life to
fewer domains of functioning
– optimization: people engage in behaviors to
enrich their lives
– compensation:developing suitable, alternative
adaptations
THE END!
Thanks for hanging in there!