Human Development and Aging


Author: Adekola Taylor
November, 2013


The understanding of human developmental stages and aging has helped a lot in proffering solutions to most of the health and social challenges of life. Life stages starts at infancy and ends at old age and it is generally accepted that the mystery of aging is enshrined in the process of human development. Life begins with a one-celled zygote that is made possible through fertilization of the ovum by spermatozoon. It progresses sequentially to prenatal development, birth, infancy and childhood, adolescence, young adulthood, middle age, and old age. Some scientists believe that the clock of aging could be brought backward or even stopped if the process of human developmental stages leading to ageing could be slow down or re-adjusted.

In recent times, many anti-aging drugs e.g. anti-oxidants have been produced to reduce the process or symptoms of aging, and to improve healthy living. Invariably, the anti-aging scientists believe that if the process of aging is slow down or overhauled either through biological or genetic engineering then there would be a profound increase in the average life expectancy. In recent years, the life span of mice, roundworms and fruit flies were extended by some biologists through genetic engineering, changes in diet, and selective breeding (Hayflick, 1998; Medina, 1996). There are many factors among humans that influence life expectancy and they include personality, genetics, health practices, nutrition, health care, and the environment.

With advanced healthcare delivery methods especially in United States life expectancy increased from 47 in the year 1900 to 76.9 in 2000. Furthermore, it is germane to note that some physical changes that are related to aging are obvious; among them are the wrinkling of the skin, additional weight around the midsection and graying hair (Cecie & McMillan, 2010). Some of the age-related changes develop unnoticed for decades, for instance the waned resiliency of blood vessels and the gradual loss of bone tissues. The understanding of human development as regards to body changes with age can be used to curb the changing in the organ, tissue and cell functions to slow down the ageing process, and to prevent most of the diseases associated with aging e.g. diabetes, hypertension and eye disease.

Physical Changes in Adulthood

At the stage of birth, a human infant possesses over 100 billion brain cells but as the human infant grows in age, some of these cells die without replacement and those that are not dead become thin out. It is important to note that not all of the brain cells age at the same time. The part of the brain that controls simple reflexes, the brainstem, loses no or little cells over time. But the frontal and the motor lobes which are responsible for the control of both cognitive and motor activity lose hundreds of neurons a day, especially after the age of fifty (Salthouse, 2009). Besides changes within the brain, aging causes other physical changes such as decline in heart and lung capacity, decline in muscle strength and speed of reflexes, decline in vision, loss of sense of taste, joints stiffen, immune system starts to fail, and smell is reduced. For example, osteoporosis is a common debilitating and painful bone disease in old age.

The process of osteoporosis accentuates after 50 years leading to bone loss and weakened bone. Bone loss with age is inevitable but the rate can be reduced. Furthermore, many older people experience auditory losses, loss in height, stooped posture, shrinkage, and trouble hearing high-pitched sounds, normal speech, and background noise (Whitbourne, 2002). Menopause, the end of menstruation, is one of the unavoidable physical changes that occur in women. Women between the ages of 45 and 55 stop menstruating as result of the stoppage of the production of oestrogen by the ovaries. This is usually accompanied with symptoms such as hot flashes, nausea, dizziness, headaches, and profuse sweating.

While some women may get depressed or moody by menopause some are indifferent to it. However, a study reports that major depression popularly believed to be associated with menopause in women is highly exaggerated (Brim et al., 1999). For men the testosterone levels which normally peak at adolescence begin to reduce gradually but the fertility of the sperm is unaffected. It is worth noting that aging is not only a biological process but also a psychological process for both men and women.


Aging and Intellectual Functions

Aging is as a result of long time accumulation of changes which may be biological, psychological, social and physical. In adulthood some of these changes may grow or improve with aging while some may decline with aging. Many questions have been asked about the relationship between aging and intellectual functions. Some of these questions are: At what age do growth and development result to aging? Does a weakened body signify a declined intellectual ability? How is cognitive development affected by the process of aging? It has been shown scientifically that cognitive abilities may relatively reduce with age, especially with abilities such as executive functions, and short-term memory (Albert, 1993). Nonetheless, there are some selected groups of aged individuals who experience apparently no change in cognitive abilities with age, no high probability of disease, and no passive engagement with life.

The individuals in this aforementioned category are often considered as examples of successful aging while those with marked cognitive decline with age, typified by a state of dementia e.g. Alzheimer's disease are considered as examples of unsuccessful aging (Perls, 2006). Undoubtedly, aging has profound effects on memory and forgetting. As a matter of fact, the neuro-cognitive bases for age-related decline in memory are based on changes in sensory acuity and neural speed. As people age, their hearing and eyesight become impaired, and their neural speed decline. It has been shown that the loss of neural speed associated with aging leads to impairment of cognitive performance as a result of slow processing of information and slow reaction (Salthouse, 2009). This is because the nervous system is slow in response and this in turn will increase the time it will take to process information.

As earlier mentioned, dementia is a common severe cognitive state that affects nearly 10% of the older population. It may occur at any stage in adulthood but it is common at the age of sixty and above. One major disease that causes state of dementia in elderly population is Alzheimer's disease, which is responsible for damaging of brain cells that resulting to loss of memory. Alzheimer's disease may not necessarily be the result of part of the aging process but it is crystal clear that damage to the brain due to tumor, stroke, and accumulative effects of alcohol drinking is the major cause.

Alzheimer's disease

The effects of Alzheimer's disease are devastating and worsen over time. It starts with simple memory lapses, and graduates to attention problems and finally loss of cognitive functions. The exacerbation of the disease is associated with bursts of anger, periods of disorientation, depression, deterioration of physical functions, changes in personality and mood. For now, Alzheimer's disease has no means of cure or prevention. It is generally believed that when an old person is diagnosed with Alzheimer's disease, such a person may not live up to an average of nine more years. However, there are centers designed to help people with Alzheimer's disease in coping with challenges attached to the disease. Patients in the early stage of Alzheimer's disease may undergo memory-retraining program to instruct them how they can use external memory aids and mnemonic devices.


Many psychological and biological changes occur as a person grows from infancy to adulthood. During the twenties, heart and lung capacity, muscle strength, vision and speed of reflex drastically increase and at the age of thirty they peak, then they gradually begin to reduce with increase in old age. At this stage the efficiency of the bodily systems begin to reduce e.g. metabolism starts slowing down, changing of physical and cognitive functions. Eating of good diet, healthy style of life, and exercise habits may also help to reduce the profound effects of aging. Finally, the understanding of human development through the knowledge of biology and psychology has made us to know much about the process of aging. This in turn has tremendously helped in gerontology by proffering solutions to some of the critical challenges attached to aging.

See Also: Dreams, Visions, and Empowerment; Multiple Intelligences; The Etiology of IQ; The Bane of Plagiarism; Stop Teen Cosmetic Surgery; Your World and You; Thoughts; How to Stop All Your Bad Habits in just 21 Days; Thinking for You Series; The Black People: We Need A Change; Logical-Mathematical Reasoning for Teens; Regenerative Mathematics and Dimurelo Puzzles for Children; The Thoughts You Need to Think; Mathematical Discoveries; The Foundation of American Constitution: A Lesson for All


Albert M.S. (1993) Neuropsychological and neurophysiological changes in healthy adult humans across the age range.Neurobiol. Aging 14:623. [PubMed: 8295666].

Brim, H., Heyndrickx, M., De Vos, P., Wilmotte, A., Springael, D., Schlegel, H. G. & Mergeay, M. (1999). Amplified rDNA restriction analysis and further genotypic characterization of metal-resistant soil bacteria and related facultative hydrogenotrophs.Syst Appl Microbiol.22:258-268.

Cecie Starr, Beverly McMillan (2010).Human Biology(10th Ed). USA:Brooks/Cole/Thomson Learning.

Hayflick L. (1998). How and why we age.Exp Gerontol. 33(7-8):639-53.

Medina J (1996).The Clock of ages: Why we age - How we age - Winding back the clock. Cambridge: Cambridge Univ. Press.

Perls T.T. (2006). The different paths to 100.Am. J. Clin. Nutr. 83:484S. [PubMed: 16470017].

Salthouse, Timothy A. (2009).When does age-related cognitive decline begin?Neurobiology of Aging, 30 (4): 507-514. doi:10.1016/j.neurobiolaging.2008.09.023.PMC 2683339. PMID 19231028.

Whitbourne, S.K. (2002).The aging individual (2nd Ed.). New York: Springer

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