Aging of whole organisms is a complex process that can be defined as a progressive deterioration of physiological function, an intrinsic age-related process of loss of viability and increase in vulnerability. Many psycholological and physical changes in humans can be brought about by aging, it is the most normal and regular process that affect human beings either positively or negatively. The most important stage of aging can be felt in the transition period that is from middle to old age graying of hair, skin wrinkles, muscle weakening can be an indication of changes in age manifested by individuals as a measure of health and physical manifestations.
Most human beings identify with their bodies and aging of the body for instance naturally brings about the aging of mind accompanied by the decline of physical strength and at times psychological strength. In the end result the poor psychological health affects a great deal the physical well-being of an individual (Saberi Roy, 2009).
Historical Development of Theories of Aging
History has it that gerontologists tried to look for ways that might help them unravel the mystery of aging in humans, through this they had to look at the well-known historical literature among these the holy Bible, medieval allegories, Sanskrit, literature on archaeological findings and other ancient texts trying to explain individual differences in the well being and maintenance of competence through the various stages of live (Hall, 1922).
These models of aging typically can be said in reality to have a broad world view, for instance if we look at the biblical admonition it is believed that obedience to God's commandments would result into longer life.
However new historical literature contexts have resulted to new explanations of aging for instance the modern biological conception of the advantages of aging in female and the medieval explanations of older females as witches. But also there in are critiques included as in Hall's writings of the contemporary societal arrangements.
In Cowdry's classical opus problems of aging, numerous views of how complex aging can be maybe found. In his views Cowdry asserts that aging resulted from degenerative diseases to contentions that social context affects the expression of aging, this resulted to the difference other writers like Rowe and Kahn (1997) referred to the difference between normal and successful aging. The twentieth century has witnessed an accumulation of more scientific insights, resulting to a movement occurring from wider world views on the process of aging to more circumscribed theoretical models driven by perspectives which are disciplinary in nature notwithstanding the fads and explanatory frameworks that have waxed the scientific enterprise (Hendricks & Achenbaum1999).
Biological Theories of Aging
The biological theory behind the biological basis of human aging hold that senescence is as a results of genetically determined process, or base aging on stochastic theories that postulate senescence as the primary result of the random damage to the organism. Most recently however, the most popular biological theories include:
(a) The free radical theory- which has it that various reactive oxygen metabolites can cause extensive cumulative damage
(b) Caloric restriction- which holds that both lifespan and metabolic potential can be modified by caloric restriction (however so far it is not demonstrated in humans)
(c) Somatic mutation- which argues that genetic damage originally caused by background radiation
(d) Hormonal theories- which propose, for instance, that elevated levels of steroid hormones produced by the adrenal cortex can cause rapid aging decline
(e) immunological theories- that equate aging to the decline in the immune system. Another well-known perspective is that the protective and repair mechanisms of cells are insu-cient to deal with the cumulative damage occurring over time, limiting the replicative ability of cells (Cristofalo et.al., 1999).
Stress Theories of Aging
Stress theories of aging have it that excessive physiological activation has pathological repercussion in that aging patterns differences are influenced by the neuroendocrine reactivity. However this focus of such theories does not specify on a particular disease outcome, but rather on the belief that neuroendocrine reactivity might be related generally to rising risk of disease and disabilities.
Mechanisms of stress are believed to interact with the age changes in the hypothalamic pituitary adrenal (HPA) axis, which is one of the systems responding to stressors and homeostatic integrity maintenance in the body. Cumulatively individual difference in reactivity can lead to differences in neuroendocrine aging also on age related risks for disease. Also it is of importance to note that certain psychological factors can have an impact on endocrine reactivity. Type A behavior and the perceptions of control patterns have or may have an impact on increased reactivity with age. Difference in neuroendocrine reactivity in gender is evident as a result of postmenopausal increase in cortisol secretion in women not treated with estrogen replacement therapy ( Finch and Seeman 1999).
Psychological Theories of Aging:
Theories of psychological aging lay emphasis on a few substantive domains as there seems to be not many overarching theories that apply to different life stages. However to this exception is the recent observation on the theory of selection, optimization and compensation (SOC) advocated by P. Baltes (1990, 1997).
The theory argues that there are psychological gains and losses at every level of aging, however at old age the psychological losses are more than gains. He further argues that evolutionary development up to the very last stage of life remains incomplete, as a result societal support no longer comes up to compensate for the decrease in physiological infrastructure and losses in behavioral functionality (Baltes and Smith 1999).
There comes up a different between cognitive abilities that are built and process abilities thought to be genetically over determined and which however the difference seem to reduce the lifespan of an adult, crystallized abilities believed to be learned are specific to a particular cultural orientation which seem to build up into advanced old age.
However these differences seem to break down in advanced old age as decreased sensory capabilities and decrease in processing speeds lead to decreased crystallized abilities. With regard to this however most theories of adult cognition have had a focus on explaining the decrease in build abilities overlooking to explain or theorize why is it that crystallized performance always remains at high levels into old age (late life). Perspectives on cognitive aging are grouped in a manner that suggests their main causal influences which can be either distal or proximal in nature. Distal theoretical perspectives hold that cognitive aging is as a result of influences that occurred at the earlier periods in life of a human.
Moreover other explanations have a focus on social-cultural changes that have had effect on cognitive performance, which assume that these effects once accumulated may lead to the obsolescence of the elderly. The importance of these theories comes about when they try to explain why the observed age difference has emerged since many written literatures concur that mere passage does not account for this differences.
On the other hand proximal theories of aging deal with the influences that are believed to determine age-related disparities in cognitive performance, that is to say these theories do not pinpoint to the origin of age differences. The major variation of these theories include quantitative difference in the efficiency of information processing stages which implicates a deficit in specific stages, strategy based age difference which can alter the operation of either one or more processes of cognition. (Salthouse, 1999)
Sociological Theories of Aging
Anthropological Theories: early anthropological theoretical formulations have a proposition on a quasi-evolutionary theory that link the marginalization of older people to modernization. As of now current theories are informed by the studies carried out in the context in which elderly people are living in a range of age -- integrated communities as opposed to those in the cities and urban settings, as well as by the investigations on the special populace that include among others ethnic groups and people with disabilities.
Most theoretical themes addressed currently include among many others the change of life course across different cultural settings, the complexity of the elderly in society which leads to the differences in age experienced in different cultural context, the diversity of aging within cultures and so forth. Generational system is considered by anthropologist as the best way of thinking about the life course.
They hold that every society has generational guidelines that organize social lives, in this respect generations have little or nothing to do with chronological time, but rather designate positions in a web of relationships thereby emphasizing on kinship systems. In primitive societies anthropologist hold that age-class systems have more explanatory powers, but they may not be of any help as life course models in complex societies as a result of their variability, in reality age class systems are more likely to explain social structuring in males as opposed to females.
Anthropologists make a distinction between theories that talk about age from those about aging or the aged. Age is depicted as a social or cultural phenomena, age is…