Cultures tend to value long life, full of experiences and community service. Throughout the evolution of the human species, longevity has been a factor in survival, fitness, and natural selection. We have evolved the characteristic of living an extended time after being reproductive, which is unique among animal species. Especially, females have a long post-reproductive stage, called menopause. There are several theories about why females have adapted menopause.
Among mammals, humans also have the longest maximum life span, the greatest possible length of time a member of a given species will live. Life span is often limited by life expectancy. Life expectancy refers to the expected years a person will live in a given population. This number of years is based on various criteria specific to a population. Life expectancy is also always fluctuating.
Populations within poor developing countries tend to have a low life expectancy. For instance, in 1980, 13 nations in Africa had an average life expectancy of 45 years or less. In 1980, the US population’s average life expectancy was 73 years. The differences in life expectancies exist because of the differing conditions a human population faces in a given social and physical environment. These conditions include disease, diet deficiencies, radiation, war, chemical pollution, accidents, extreme environmental or climatic conditions, and mental and physical stress.
An increase in life expectancy has been occurring worldwide. The increase could be due to improved health care, better diet and higher quality food, decreased environmental hazards, and better sanitation. The life expectancy increase results in a higher percentage of elderly in a population. Paros, Greece currently has one of the highest percentages of people living past a hundred years, or centenarians. However, one problem exists among societies with a large percentage of elderly.
Medical technology has helped to improve life expectancy worldwide, but it also caused a shift in the medical concerns of elderly people. Previously, the major cause of death was infectious diseases, but this has changed to chronic diseases. This shift is also called the “epidemiologic transition.” The treatment of chronic diseases may cause more pressure on a culture, especially a culture that values the personal family care of an elderly individual. In such a culture, elderly people eventually may need care by a trained professional and need closer proximity to medical equipment. In this case, the family often goes against cultural values for the good of the elderly individual and places their loved ones in a medical institution to fit their needs. Institutionalization of elders with chronic diseases seems to be more prevalent in industrialized societies.
Written by Rachel Frisk, 2000