Chapter 17 Summary
Vastly different rates of aging are apparent in late adulthood. A complex array of genetic and
environmental factors combine to determine longevity. Dramatic gains in average life expectancy
confirm that biological aging can be modified by environmental factors, including improved nutrition,
medical treatment, sanitation, and safety. Although most Americans over age 65 can live independently,
some need assistance with activities of daily living or, more commonly, with instrumental activities of
daily living, such as shopping and paying bills.
The programmed effects of specific genes, as well as the random cellular events believed to underlie
biological aging, make physical declines more apparent in late adulthood. Although aging of the nervous
system affects a wide range of complex activities, research reveals that the brain can overcome some
decline. Changes in sensory functioning become increasingly noticeable in late life: Older adults see and
hear less well, and taste, smell, and touch sensitivity may also decline. Hearing impairments are more
common than visual impairments and affect many more men than women. Reduced capacity of the
cardiovascular and respiratory systems becomes more apparent in late adulthood. As at earlier ages, not
smoking, reducing dietary fat, avoiding environmental pollutants, and exercising can slow the effects of
aging on these systems. The immune system functions less effectively in late life, permitting diseases to
progress and making autoimmune responses and stress-induced infection more likely. As people age,
they have more difficulty falling asleep, staying asleep, and sleeping deeply—a trend that begins earlier
for men than for women. Outward signs of aging, such as white hair, wrinkled and sagging skin, age
spots, and decreases in height and weight, become more noticeable in late adulthood.
Problem-centered coping strategies yield improved physical functioning in older adults, and assistive
technology is increasingly available to help older people cope with physical declines. Physical and mental
health are intimately related in late life.
The physical changes of late life lead to an increased need for certain nutrients, and exercise continues
to be a powerful health intervention. Although sexual desire and frequency of sexual activity decline in
older people, longitudinal evidence indicates that most healthy older married couples report continued,
regular sexual enjoyment. Illness and disability climb as the end of the lifespan approaches.
Cardiovascular disease, cancer, emphysema, and stroke claim many lives, while arthritis and type 2
diabetes increase substantially. At age 65 and older, the death rate from unintentional injuries is at an
all-time high. Dementia refers to a set of disorders occurring almost entirely in old age in which many
aspects of thought and behavior are so impaired that everyday activities are disrupted. Alzheimer’s
disease, the most common form of dementia, can be either familial (which runs in families) or sporadic
(where there is no obvious family history). Although no cure is available, immune globulin is among the
promising drug therapies. Careful diagnosis is crucial because other disorders can be misidentified as
dementia.
Family members provide most long-term care, especially among ethnic minorities with close-knit
extended families. Individual differences in cognitive functioning are greater in late adulthood than at
any other time of life. According to one view, older adults can make the most of their cognitive
resources through selecting personally valued activities, to optimize returns from their diminishing
energy, and then finding new ways to compensate for cognitive losses.
Research shows that language and memory skills are closely related. Although language comprehension
changes very little in late life, retrieving words from long-term memory and planning what to say
become more difficult. In everyday problem solving, older adults are effective as long as they perceive
problems as important and under their control.
Cultures around the world assume that age and wisdom go together. Older adults with the cognitive,
reflective, and emotional qualities that make up wisdom tend to be better educated and physically
healthier and to forge more positive relations with others. Heritability research suggests a modest
genetic contribution to individual differences in cognitive change in late adulthood, but a mentally active
life is vital for preserving cognitive resources. And interventions that train older adults in cognitive
strategies can partially reverse age-related declines in mental ability. Seniors who participate in
continuing education through university courses, community offerings, and programs such as Road
Scholar acquire new knowledge and skills, new friends, a broader perspective on the world, and an
image of themselves as more competent.
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