CHAPTER 17
PHYSICAL AND COGNITIVE DEVELOPMENT
IN LATE ADULTHOOD
RESOURCES-AT-A-GLANCE
Detailed Outline
Learning
Objectives
Instructor’s Resources
Test Bank
MyPsychLab Connections
Chapter Introduction pp. 417-418
PowerPoint Slides
1-4
SA 1
Sketchnote Video
Late Adulthood
Variability in Late Adulthood
Lecture Enhancer
5-16
MC 1-20
Watch
Late Adulthood, p. 419
Active Seniors, p. 423
Physical Changes pp. 423-429
The Brain and Nervous System
The Senses
Theories of Biological Aging
Behavioral Effects of Physical Changes
17.3
17.4
17.5
17.6
PowerPoint Slides
17–31
MC 21-56
FI 81–88
SA 95–97
ES 109–111
Watch
Late Adulthood: Happiness
and Attitude toward Aging, p.
423
Ear Ringing, p. 424
Depression in Later Life, p. 432
Mental Health pp. 429-434
PowerPoint Slides
MC 57-70
Watch
CHAPTER OVERVIEW
Most older adults experience some degree of physical and cognitive declines. Thus, the experience of
aging often involves learning to offset weaknesses, such as increasing forgetfulness, with strengths, such
as practicality and inventiveness.
The elderly are often classified as young-old (60-75), old-old (75-85), and oldest-old (85+). The oldest-
old are the fastest-growing group of elderly. There are significant individual differences in aging among
Neurons are less dense in the elderly than in younger adults, resulting in slower reaction times to a variety
of stimuli. Changes in vision and hearing affect the lives of most elderly adults. The senses of smell and
touch become less sensitive in the later years. Aging theorists suggest that there may be genetic limits on
the human lifespan. Further, the cumulative effects of cell malfunctions may be responsible for primary
LEARNING OBJECTIVES
After completing Chapter 17, students should be able to answer the following questions:
17.1 What factors contribute to life expectancy and longevity?
17.2 What variables contribute to individual differences in health among older adults?
17.3 How does the brain change in late adulthood?
17.4 What types of sensory changes occur in late adulthood?
KEY TERMS
activities of daily living (ADLs) (p. 421)
Alzheimer’s disease (p. 429)
cross-linking (p. 426)
dementia (p. 429)
frail elderly (p. 421)
free radicals (p. 426)
gerontology (p. 418)
Hayflick limit (p. 425)
instrumental activities of daily living (IADLs) (p. 421)
INTEGRATED CHAPTER TEACHING NOTES
VARIABILITY IN LATE ADULTHOOD (pp. 418-423)
MyPsychLab Connections
Watch: Late Adulthood: Portraits of Late Adulthood Health, p. 418
Watch: Centenarian, p. 418
Watch: Late Adulthood: Physical Health in Late Adulthood, p. 419
Watch: Active Seniors, p. 423
The scientific study of aging is known as gerontology. For many years, gerontologists thought about old
Life Expectancy and Longevity
LO 17.1 What factors contribute to life expectancy and longevity?
Trends in Life Expectancy
Life expectancy in the industrialized world these days is far greater than in the past. Life expectancy is
strongly influenced by the fact that the highest death rates in the entire human lifespan are found in the
Discussion Launcher (Learning Objective 17.1, p. 418)
Do the math. Calculate the average life expectancy of ten people if all of them lived to be at least 60
years old. Then calculate the average if one of them died before age one (average in a zero).
In the United States, the average male born today is expected to live to 75 year and the average female is
expected to live to age 80. Because of these sex differences, there are more elderly women than there are
men.
Discussion Launcher (Learning Objective 17.1, p. 418)
What do these statistics tell you about the health-care needs of the elderly?
Life expectancy varies by racial group as well. In general, 65– to 74-year-old White Americans have
Subgroups
Gerontologists divide the later years into the young old (60 to 75), the old old (75 to 85), and the oldest
Discussion Launcher (Learning Objective 17.1, pp. 418-419)
Give examples of the elderly you know who fit each of the three subgroups.
Feature Box Activity (Learning Objective 17.1, p. 419)
No Easy Answers: The Coming Demographic Crisis
Conduct a classroom debate on the pros and cons of elderly entitlement reform.
Health
LO 17.2 What variables contribute to individual differences in health among older adults?
The majority of older adults do not suffer from ailments that seriously impair their day-to-day
functioning. Moreover, the inevitable physical declines that are associated with aging do not seem to
decrease older adults’ satisfaction with their lives.
Self-Rated Health
A majority of older adults regard their health as good. This contradicts stereotypes of old age as a period
of illness, but the proportions of elderly with good health are a great deal lower than the equivalent
proportions for young and middle-aged adults. Thus, health is the single largest factor determining the
Discussion Launcher (Learning Objective 17.2, pp. 419-420)
Give examples of diseases that may cause increased declines in late adulthood.
Limitations on Activities
Gerontologists generally define disability as a limitation in an individual’s ability to perform certain
socially defined roles and tasks, particularly self-help tasks and other chores of daily living. Daily living
tasks are grouped into two categories:
▪ Activities for daily living, or ADLs, include bathing, dressing, using the toilet, and so forth.
▪ Instrumental activities of daily living, or IADLs, include activities that are more intellectually
challenging, such as managing money.
Chronic Health Conditions
The prevalence of chronic health conditions increases with age. The most common of these conditions
are hypertension, also known as high blood pressure, followed by arthritis, inflammation in the joints that
causes pain and stiffness. Not everyone with these problems is disabled, but the risk of some kind of
functional disability is two to three times higher among elders who suffer from these diseases than among
those who do not.
Discussion Launcher (Learning Objective 17.2, pp. 421-422)
What can we do before we reach late adulthood to help prevent, or at least postpone, the onset of
disabilities?
Racial and Ethnic Differences
Among ethnic minorities, as among White Americans, individual variability in old age is the rule rather
than the exception. Averages in life expectancy and disabling conditions differ across groups, but a
Heredity
Some general tendency to live a long life is clearly inherited. Identical twins are more similar in length of
life than are fraternal twins, and adults whose parents and grandparents were long-lived are also more
likely to live longer.
Discussion Launcher (Learning Objective 17.2, p. 422)
How many people in your family have lived past the age of 80? Did those who died younger do so
because of a controllable lifestyle factor, such as smoking?
Health Habits
The same health habits that are important predictors of longevity and health in early adulthood continue to
be significant predictors in late adulthood. Perhaps the most crucial variable is physical exercise, which
Discussion Launcher (Learning Objective 17.2, p. 422)
In teams, design a program to promote physical exercise among the elderly. Share each team’s project
with the rest of the class.
Critical Thinking Question (Learning Objectives 17.1-17.2, pp. 418-423)
How would you characterize your own chances for a long life based on the genes you have inherited and
on your health habits?
PHYSICAL CHANGES (pp. 423-429)
The Brain and Nervous System
LO 17.3 How does the brain change in late adulthood?
There are four main changes in the brain during the adult years: a reduction of brain weight, a loss of
gray matter, a loss of density in the dendrites, and slower synaptic speed. The most central of these
changes is the loss of dendritic density. The loss of dendrites in middle and late adulthood does not seem
to be the same type of pruning as in infancy and childhood. Rather, it appears to be a decrease in useful
dendritic connections.
Discussion Launcher (Learning Objective 17.3, p. 423)
How do you explain the evidence that education itself is the cause of the reduced atrophying of the
cerebral cortex?
Dendritic loss also results in a gradual slowing of synaptic speed, with consequent slowing of reaction
time in many everyday tasks. Neural pathways are redundant enough that it is nearly always possible for
The Senses
LO 17.4 What types of sensory changes occur in late adulthood?
Vision
In addition to presbyopia (farsightedness), vision in old age is affected by a variety of other body changes.
▪ Blood flow to the eye decreases resulting in an enlarged “blind spot” on the retina and a reduced field
of vision.
▪ The pupil does not widen or narrow as much or as quickly resulting in more difficulty seeing at night
and responding to rapid changes in brightness.
Hearing
Wear and tear on the auditory system results in some hearing loss (presbycusis) beginning in middle
Discussion Launcher (Learning Objective 17.4, p. 424)
How do you think a hearing impairment is likely to affect the life of an older adult? Aside from wearing
a hearing aid, how could a person with a moderate hearing impairment adapt his life so as to reduce the
impact of the disability?
Hearing difficulties of persons in late adulthood have several components:
▪ Loss of ability to hear high-frequency sounds
Even mild hearing loss can pose communication problems in some situations. Mild and moderate hearing
Taste, Smell, and Touch
The ability to taste the four basic flavors (salty, bitter, sweet, and sour) does not seem to decline over the
years of adulthood. Other changes in the taste system affect older adults, however, such as less saliva,
producing a “woolly mouth” for some. Many elders report that flavors seem blander than in earlier years,
Discussion Launcher (Learning Objective 17.4, p. 425)
Why might the loss of sensitivity to odors become a health hazard for the elderly?
Discussion Launcher (Learning Objective 17.4, p. 425)
How might teeth and/or dentures impact an older person’s eating habits?
The skin of elderly adults is also less responsive to cold and heat. The loss of sensitivity occurs in a
pattern that is a reversal of the proximodistal principle of growth. In other words, the extremities, usually
Discussion Launcher (Learning Objective 17.4, p. 425)
If you were the caregiver of an elderly adult, what precautions could you take to help prevent health and
safety problems caused by the loss of sensitivity to touch?
Theories of Biological Aging
LO 17.5 How do theories explain biological aging?
The most current theories of physical aging emphasize the basic cellular processes, which appear to
change with age in specific ways that reduce the efficiency of cellular functioning.
The Hayflick Limit
Species vary widely in how long, on average, individuals live. These differences have persuaded some
biologists that there may be a universal genetic process that triggers age-related declines and limits the
lifespan. For humans, the maximum lifespan seems to be about 110 or 120 years. Biologist Leonard
Hayflick observes that embryo cells placed in nutrient solution will divide only a fixed number of times,
Genetically Programmed Senescence
Senescence is the gradual deterioration of body systems that happen as organisms age. The programmed
senescence theory suggests that age-related physical declines result from species-specific genes for aging.
Discussion Launcher (Learning Objective 17.5, p. 426)
Give examples of senescence.
Repair of Genetic Material and Cross-Linking
Another explanation focuses on the cell’s ability to repair breaks in DNA. Breaks in DNA are common
events, resulting from unknown metabolic processes. Because the organism is apparently unable to repair
all the damage, the accumulation of unrepaired breaks results, over time, in loss of cellular function, and
the organism ages.
Discussion Launcher (Learning Objective 17.5, p. 426)
Give examples of how the cell’s declining ability to repair DNA breaks results in loss of cellular function.
A related theory focuses on another cellular process called cross-linking, which occurs more often in cell
proteins in older than in younger adults. Cross-linking occurs when undesirable bonds form between
Free Radicals
A third type of cellular process that may contribute to aging relates to the body’s ability to deal with free
radicals. Free radicals, which are molecules or atoms that possess an unpaired electron, are a normal by-
product of body metabolism as well as exposure to certain substances in food, sunlight, X-rays, or air
pollution. These radicals, especially the subgroup called oxygen free radicals, enter into many potentially
damaging chemical reactions, resulting in irreparable molecular damage that accumulates with age.
Oxidation reactions caused by free radicals can damage cell membranes, thereby reducing the cell’s
protection against toxins and carcinogens.
Research on diet variations points to the possibility that some foods, especially food high in fat, promote
the formation of oxygen free radicals, while others, referred to as antioxidants, inhibit it or produce
Terminal Decline
Some theorists claim that physical and mental declines in old age are actually part of the dying process.
The terminal decline hypothesis asserts that all adults retain excellent physical and mental function until
Behavioral Effects of Physical Changes
LO 17.6 What are the behavioral effects of changes in the various body systems of older adults?
General Slowing
The biggest single physical effect of aging is a general sense of slowing down. Dendritic loss at the
neural level clearly contributes substantially to this general slowing, but other factors are also involved,
including arthritic changes in the joints and loss of elasticity in the muscles. Everything takes longer,
even tasks that involve word skills. The decline in the speed of nerve impulses may be responsible for
Discussion Launcher (Learning Objective 17.6, pp. 427-428)
How would this information affect you if you were caregiver for an elder?
Sleeping and Eating Patterns
A shift in sleep patterns in old age is a primary aging pattern. Adults older than 65 typically wake up
more frequently in the night and show decreases in rapid eye movement (REM) sleep, the sleep state in
which dreaming occurs. Older adults are also more likely to wake early in the morning and go to bed
Discussion Launcher (Learning Objective 17.6, p. 428)
How might a nap in the middle of the day have a different effect for a college-aged person than for an
elder?
The ability of the brain to regulate appetite also changes with advancing age. When you eat, your blood
Motor Functions
The various physical changes associated with aging also combine to produce a reduction in stamina,
dexterity, and balance. The loss of stamina clearly arises in large part from the changes in the