1.
THEORIES OF
AGING

2.
OBJECTIVES
At the end of this session students will be able
to:
define aging
explain the theories of aging

3.
INTRODUCTION
Aging:
Aging is the process of becoming older.
Ageing represents the accumulation of changes in a
human being over time, encompassing physical,
psychological, and social changes.
Reaction time, for example, may slow with age,
while knowledge of world events and wisdom may
expand.

4.
THEORIES OF AGING
Biological theories
Psychological theories
Environmental theories
Developmental theories

5.
BIOLOGICAL THEORIES
Cellular theory:
Cells has been subject of much scientific
inquiry in exploring aging phenomena.

6.
CONTD..
Cells has three distinct components:
•Cells that can reproduce
•Cells that cannot produce
•Intercellular substance/materials

7.
CONTD…
Programmed theory:
According to this theory aging and death are natural
and necessary part of genetics.
The human are programmed to age and die.

8.
CONTD…
Error theory:
Aging is a result of internal and external assaults
that damage cells or organs so they can no longer
function properly.
Mistranscription and mistranslation of certain
genes products results in self amplifying error
producing derangement.

9.
CONTD…
Somatic theory:
The theory states that aging is an imbalance
between DNA’s ability to repair itself and
accumulating DNA damage.
When the damage exceeds the repair, the cell
mutation, this lead to senescence.

10.
CONTD…
Wear and tear theory:
Years of damage to cells, tissue and organs
eventually wears them out.
Wear and tear can be viewed as a result of aging and
not the cause of it.

11.
CONTD…
Auto immune theory:
Postulates that with age, immune system
produces auto anti-bodies that causes cell death
or changes that foster the aging process.

12.
CONTD…
Free radical theory:
During aging, damage produced by free radicals
cause cells and organs to stop functioning.
Molecules that are damaged by free radicals are
proteins and DNA.

13.
CONTD…
This theory purpose that little by little small
damage accumulates and contributes to detoriation
of tissue and organs.

14.
CONTD…
Cross linkage theory:
Also known as collagen theory.
With age, protein, DNA and other structured
molecules develop inappropriate cross links to one
another which decreases the elasticity of protein
and other molecules.
Damage and unneeded protein stick around and
can cause problem.

15.
PSYCHOLOGICAL THEORIES
Activity theory (Havighrust 1963):
The activity theory basically says: the more you do,
the better you will age.
The activity theory occurs when individuals engage in
a full day of activities and maintain a level of
productivity to age successfully.

16.
CONTD…
Disengagement theory(Cumming & Henry
1961):
This theory viewed aging as a process through which
society and the individual gradually withdraw or
disengage from each other.

17.
CONTD…
Continuity theory(Negatron 1964):
The continuity theory states that individual who
age successfully continue habits, preferences,
lifestyle and relationship through midlife and later.

18.
CONTD…
Social exchange theory:
Postulates that social interaction between
individuals and groups continues as long as
everyone profits from the interaction.
The decrease in the social interaction of the aged
is the result of exchange relationship that gradually
erodes the power of the aged.

19.
ENVIRONMENTAL
THEORIES
Radiation theory:
Excessive exposure to the suns radiation puts the
skin at risk during the somatic mutation process.

20.
CONTD…
Stress theory:
According to Perlman(1954)
’Human aging is a disease syndrome arising from a
struggle between environmental stress and
biological resistance and relative adaption to the
effects of stressor agents. These stressors agents
might include air, pollutant, chemical,
psychological and sociological events.’

21.
DEVELOPMENTAL
THEORY
Erikson theorized that person’s life consists of
eight stages.
Each stage represents a crucial turning point in life
stretching from birth to death, with its own
developmental conflicts to be resolved.