Defintions

In this unit we will cover information about the aging of the world’s population. There are two definitions that need to be explained at the outset:

Developed and developing countries. Throughout this background paper we refer to developing and developed (industrialized) countries. The classifications that we use are those created by the United Nations. Developed countries are all nations in Europe including the countries which were part of the former Soviet Union, as well as North America, Japan, Australia, and New Zealand. All other nations of the world are considered to be developing countries. When one examines statistics about the elderly, you will notice that a number of countries that are considered "developing" have populations that are more like developed countries with relatively low birthrates, low mortality, and high life expectancy.

Elderly, Old, Aged. These words are used interchangeably. The definition of the aged that we use is anyone aged 60 and above, since this is how most world statistical information is reported (based on UN Resolution 35/129) although much of the data from the US is based on 65+. Throughout this document we refer to the "young-old" as anyone aged 60 to 79 and the "oldest-old" or "frail" elderly as anyone 80+. We recognize that these are fairly large age spans that 60+ can cover over forty years and that even the use of the young-old and oldest -old categories cover age spans of around twenty years. Researchers and other aging professionals often use the categories "young-old" (65-74), "middle-old" (75-84) and old-old (85+) to be more specific and it is likely that as larger numbers of people reach their eighties and nineties that these categories will be refined. It is convenient to use age-based generalizations, such as oldest-old to broadly describe a group of people. This type of category is particularly useful to describe normative patterns of life development. However, it is now widely recognized by aging professionals that while older adults do share many characteristics, the elderly are not all alike, but differ along many dimensions. Older adults differ in terms of their individual physiological and psychological characteristics, their material security and lifestyle, and their life experiences. For example, studies show that morbidity (illness) and functional disability (difficulty in performing the activities of daily living such as cooking, bathing, keeping house) differ dramatically among older adults. These individual differences are referred to as "variability" or "heterogeneity."