Chapter 23 Summary

1. Contrary to ageist stereotypes, most older adults are quite happy, healthy, and active. Ageism, which includes stereotyping and behaviors like elderspeak, is prevalent in both the young and old, and can lead to self-fulfilling prophecies regarding health and well-being as we age.
2. An increasing percentage of the population is over age 65, but the impact of this is sometimes distorted in the media. Currently, about 13 percent of people in the U.S. population are elderly, and 90 percent of them are self-sufficient and productive.
3. Gerontologists sometimes distinguish among the young-old, the old-old, and the oldest-old, according to each group’s relative degree of dependency. Only 10 percent of the elderly are dependent (the oldest-old), and only 3 percent of the elderly are in nursing homes or hospitals.

4. The many apparent changes in skin, hair, and body shape that began earlier in adulthood continue. The senses all become less acute. Vision losses are common and critical: many elders have cataracts, glaucoma, or macular degeneration. Hearing also declines: Most older men are significantly hard-of-hearing.
5. Selective optimization with compensation for sensory losses requires a combination of technology, specialist advice, and personal determination. These three have been underutilized in the past (exemplified by the underuse of hearing aids).
6. Primary aging happens to everyone, reducing organ reserve in body and brain. Although the particulars differ depending on the individual’s past health habits and genes, eventually morbidity, disability, and risk of mortality increase. Compensation is possible and brings many benefits, including compression of morbidity.

7. Hundreds of theories address the causes of aging. Wear-and-tear theory suggests that living wears out the body; it applies to some parts of the body but not to overall aging.
8. Another theory is that genes allow humans to survive through the reproductive years but then become seriously ill and inevitably die. Some individuals have genes or alleles that lead to long life, others to shorter lives.
9. Cellular theories of aging include the idea that the processes of DNA duplication and repair are affected by aging, making repair of errors more difficult.
10. Age-related decline in the immune system may cause aging, as it contributes to elderly people’s increasing vulnerability to disease.
11. Cells stop duplicating at a certain point, called the Hayflick limit. This stoppage seems to occur when the telomeres shorten and then disappear.

12. In geographic regions noted for long, active lives among residents, some patterns of behavior suggest that lifestyle can impact life expectancy. It appears that four specific factors—diet, work, social interaction, and exercise—may lengthen life.
13. Each species seems to have a genetic timetable for decline and death. Although the average life span has clearly increased, it is disputed whether the maximum can increase.
14. The number of centenarians is increasing, and many of them are quite healthy and happy. The personalities and attitudes of the very old suggest that long-term survival may be welcomed more than feared.