Aging is any modification in an organism over time. Aging pertains to a multidimensional process of physical, psychological, and social change. Some properties of aging grow and expand over time, while others deteriorate. Reaction time, for example, may slow with age, while knowledge of world events and wisdom may expand. Research shows that even late in life potential subsists for physical, mental, and social emergence and development. Aging is a critical part of all human societies reflecting the biological changes that occur, but also reflecting cultural and societal conventions. Age is usually measured in full years and months for young children.
The term “aging” is somewhat equivocal. Differentiations may be made between “universal aging” (age changes that all people share) and “probabilistic aging” (age changes that may ensue to some, but not all people as they raise older, such as the onset of Type Two diabetes). Chronological aging, referring to how old a person is, is arguably the most candid definition of aging and may be distinguished from “social aging” (society’s expectations of how people should act as they grow older) and “biological aging” (an organism’s physical state as it ages). There is also a division between “proximal aging” (age-based effects that come about because of factors in the recent past) and “distal aging” (age-based differences that can be traced back to a cause early in person’s life, such as childhood poliomyelitis).
Differences are sometimes made between populations of children; divisions are sometimes made between the young old (65-74), the middle old (75-84) and the oldest old (those aged 85 and above). However, problematic in this is that chronological age does not correlate perfectly with functional age, i.e. two people may be of the same age, but differ in their mental and physical capacities.
Population aging is the boost in the number and proportion of older people in society. Population aging has three possible causes: migration, longer life expectancy (decreased death rate), and decreased birth rate. Aging has a noteworthy impression on society. Young people be liable to compel most crimes, they are more likely to push for political and social change, to develop and adopt new technologies, and to need education. Older people have different requirements from society and government as opposed to young people, and frequently differing values as well. Older people are also far more likely to vote, and in many countries the young are forbidden from voting. Thus, the aged have comparatively more political control.