Ageing (British English) or aging (American English) is the accumulation of changes in a person over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline. 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 exists for physical, mental, and social growth and development. Ageing is an important part of all human societies reflecting the biological changes that occur, but also reflecting cultural and societal conventions. Roughly 100,000 people worldwide die each day of age-related causes.

Age is measured chronologically, and a person's birthday is often an important event. However the term "ageing" is somewhat ambiguous. Distinctions may be made between "universal ageing" (age changes that all people share) and "probabilistic ageing" (age changes that may happen to some, but not all people as they grow older including diseases such as type two diabetes). Chronological ageing may also be distinguished from "social ageing" (cultural age-expectations of how people should act as they grow older) and "biological ageing" (an organism's physical state as it ages). There is also a distinction between "proximal ageing" (age-based effects that come about because of factors in the recent past) and "distal ageing" (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 elderly people. Divisions are sometimes made between the young old (65–74), the middle old (75–84) and the oldest old (85+). However problematic this is, 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. Each nation, government and non-government organisation has different ways of classifying age.

Population ageing is the increase in the number and proportion of older people in society. Population ageing has three possible causes: migration, longer life expectancy (decreased death rate), and decreased birth rate. Ageing has a significant impact on society. Young people tend to commit 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 influence.

Recent scientific successes in rejuvenation and extending a lifespan of model animals (mice 2.5 times, yeast 15 times, nematodes 10 times) and discovery of variety of species (including humans of advanced ages) having negligible senescence give hope to achieve negligible senescence (cancel ageing) for younger humans, reverse ageing or at least significantly delay it. In spite of the developments mentioned above and the fact that ageing is admitted to be the major cause of mortality in developed worlds, scientists consider anti-ageing and life extension research to be greatly underfunded. Although human life is declared to be a basic value in many societies, there is no strong awareness and thus demand for society to cancel human ageing. The body still technically ages after death as it still gets older from birth.

Read more about Ageing:  Early Observations, Senescence, Dividing The Lifespan, Cultural Variations, Cognitive Effects, Coping and Well-being, Successful Ageing, Political Struggle Against Ageing, Prevention and Reversal, Measure of Age, Obtaining Survey Data On Ageing

Other articles related to "ageing":

Linda Partridge
... who studies the biology and genetics of ageing (biogerontology) and age-related diseases, such as Alzheimer's disease and Parkinson's disease ... of University College London, Director of UCL's Institute of Healthy Ageing and Founding Director of the Max Planck Institute for the Biology of Ageing ...
Ageing, Disability And Home Care NSW - Complaints About Service Provision
... Between May and August 2010, the NSW Ombudsman consulted with over 300 parents and carers of children with disabilities in order to report against progress at the mid-way point of Stronger Together ... A change in government delayed the release of the report ...
Study On Global Ageing And Adult Health - See Also
... Project on Evidence and Information for Ageing and Adult Health UN Programme on Ageing WHO's Ageing and Life Course Department World Demographic and Ageing Forum Global Action on Aging ...
The Chinese Health And Retirement Longitudinal Study - Sister Studies
... (HRS) English Longitudinal Study of Ageing (ELSA) The Survey of Health, Ageing and Retirement in Europe (SHARE) Korean Longitudinal Study of Ageing (KLoSA) ...
Study On Global Ageing And Adult Health
... The Study on Global Ageing and Adult Health (SAGE) is run by the World Health Organization's Multi-Country Studies unit in the Information, Evidence and ... well-being of adult populations, and the ageing process across different countries, through primary data collection and secondary data analysis ...

Famous quotes containing the word ageing:

    But I must needs take my petulance, contrasting it with my accustomed morning hopefulness, as a sign of the ageing of appetite, of a decay in the very capacity of enjoyment. We need some imaginative stimulus, some not impossible ideal which may shape vague hope, and transform it into effective desire, to carry us year after year, without disgust, through the routine- work which is so large a part of life.
    Walter Pater (1839–1894)

    Our civilization survives in the complacency of cowardly or malignant minds—a sacrifice to the vanity of ageing adolescents.... In 1953, excess is always a comfort, and sometimes a career.
    Albert Camus (1913–1960)