CHAPTER 15
Middle Adulthood: Physical and
Cognitive Development
Physical Development
When Are We Middle-Aged?
• Developmentalists consider middle adulthood to span
the years from 40 to 60 or 65.
– The years between 60 to 65 serve as transition years into late
adulthood.
• Cognitive development is at its peak during middle
adulthood.
– Any lapse is oftentimes made up in expertise
Physical Development
• Interindividual variability
– No two people age in the same way or at the same rate
• Physiological aging
– Changes in the body’s integumentary system, senses, reaction
time, and lung capacity
• Changes in metabolism, muscle mass, strength, bone
density, aerobic capacity, blood-sugar tolerance, and
ability to regulate body temperature may be moderated
or reversed through exercise and diet.
Skin and Hair
• Gray hair occurs due to the decrease of melanin.
– Hair loss accelerates, especially in men
• Skin becomes dryer and more brittle due to fewer
keratinocytes being produced.
• Genetics, diet, hormonal balances, and exposure to sun
(especially to UV rays) all play a part in wrinkling.
• Wrinkling due to exposure to UV rays is called photo
aging.
Sensory Functioning
• Changes in vision occur mid-30’s
• Presbyopia
– Loss of elasticity in the lens that makes it harder to focus on, or
accommodate to, nearby objects or fine print; result is middle
adults may need reading glasses
Reaction Time
• Reaction time
– Amount of time it takes to respond to a stimulus
– Increases with age beginning around age 25
Lung Capacity
• Lung tissue stiffens with age
– Diminishing capacity to expand, such that breathing capacity
may decline by half between early adulthood and late adulthood
– Regular exercise can offset this loss
– First beginning to exercise in middle adulthood can expand
breathing capacity beyond what it was earlier in life
Lean-Body Mass and Body Fat
• Lean-body mass, especially muscle, declines with age.
• Rate of loss accelerates after age 45
– Fat replaces lean-body mass
Muscle Strength
• Loss of muscle lessens strength
– Change is gradual
– Exercise can compensate by increasing the size of remaining
muscle cells
• Exercise will contribute to vigor, health, and a desirable
body shape.
Metabolism
• Metabolism
– Rate at which the body processes or “burns” food to produce
energy
• Resting metabolic rate
– Also called basal metabolic rate (BMR) declines with age
• BMR drops by about 2% per decade beginning at age 20
• Middle-aged people likely to gain weight if they eat like
they did when they were younger
– Exercise helps control the weight gain
Bone Density
• Bones begin to lose density at around the age of 40.
– As bones lose density, they become more brittle and prone to
fracture
• Bones in the spine, hip, thigh, and forearm lose the most
density as we age.
Aerobic Capacity
• Cardiovascular system becomes less efficient as we age
– Heart and lung muscles shrink
• Maximum heart rate declines, but exercise expands
aerobic capacity at any age
Blood-Sugar Tolerance
• As we age, tissues in the body become less capable of
taking up glucose from the bloodstream.
• Body tissues lose sensitivity to insulin, thus blood-sugar
levels rise, increasing the risk of adult-onset diabetes.
• Adults can minimize this condition by controlling their
weight, eating less fat, and exercising regularly.
Health
Health
• Health of people aged 40-65 in developed nations is
better than it has ever been.
• Ways to increase health during middle adulthood
–
–
–
–
–
Regular medical checkups
Paying attention to diet
Exercising, avoiding smoking, drinking in moderation if at all
Regulating stress
Having supportive relationships
Leading Causes of Death
• Leading causes of death during middle adulthood are
cancer, heart disease, and accidents
• Screening for prostate cancer, breast cancer, and
cancer of the colon and rectum is necessary during
middle adulthood.
• Recommended that African-American men get screened
for prostate cancer at age 45
• Women recommended to get mammograms at age 40
• Screening for colorectal cancer recommended for both
men and women at age 50; EKG at age 50 as well
Cancer
• In many instances, cancer can be controlled or cured if
caught early.
• Cancer is a chronic, noncommunicable disease
characterized by uncontrolled growth of cells.
– Tumors can be benign (noncancerous) or malignant
(cancerous)
– Benign typically do not pose a threat to life
– Malignant tumors invade and destroy surrounding tissue
– Cancerous cells in malignant tumors can break away from
primary tumor, travel through the bloodstream to form new
tumors, called metastases
Cancer (cont’d)
• Internal factors
– such as heredity, problems in the immune system, and
hormonal factors can contribute to mutations in the DNA
• External factors
– Carcinogens
– Include some viruses, chemical compounds in tobacco and
elsewhere, and ultraviolet solar radiation
• Incidence of cancer almost triples in the decade of 55 to
64 years of age as compared to the previous decade
– Three-fourths of cancer occur in people age 55 and older
Cancer (cont’d)
• African Americans have higher than average colon and
rectal cancer death rates and incidence rates.
• African Americans have twice the death rates from
prostate cancer.
• Incidence of cervical cancer highest in Latina American
women
• American Indian and Alaska natives have lowest
survival from all cancers combined
• Lack of health insurance contributes to late diagnosis
Cancer (cont’d)
• Cigarette smoking and high-fat diet contribute to cancer
• Second-hand smoke contributes to cancer deaths.
• Treatment consists of surgery, radiation, chemotherapy,
and hormonal therapy
– Limitation of treatment is anticancer drugs kill healthy tissue as
well as diseased tissue
Figure 15-2 p315
• Lifetime Risk of
Developing Cancer
Heart Disease
• Heart disease
– Second leading cause of death in middle adulthood
– Leading cause of death in late adulthood
• Heart disease is due to insufficient flow of blood to the
heart
– Most commonly results from arteriosclerosis (hardening of the
arteries)
– Arteriosclerosis can impair circulation and increase the risk of a
blood clot, choking off the flow of blood and resulting in a heart
attack or stroke
– Most common form called atherosclerosis (buildup of fatty
deposits call plaque; arteries narrow)
Heart Disease (cont’d)
• Age, race/ethnicity, and sex are risk factors.
• No smoking, exercise, good diet, and in some cases
medication can help minimize risks.
• Getting blood pressure and cholesterol levels measured
can help identify heart health issues.
• On average, African Americans have higher risk of high
blood pressure; may contribute to dying from heart
disease due to hypertension
Figure 15-4 p317
The Immune System
The Immune System
• Immune system is the body’s defense against infections
and other sources of disease
• Immune system combats disease by the production of
white blood cells (leukocytes) and by inflammation
Stress and the Immune System
• Stress
– Suppresses the immune system by stimulating the production of
steroids, which decrease inflammation and interfere with the
formation of antibodies resulting in more susceptibility to disease
– Stress related to rapid progression of HIV infection to AIDS
• Stress hormones associated with anger may contribute
to heart attack.
• High-strain work puts workers at the highest risk.
• Stress may be linked to the increase in cancer incidence,
higher cholesterol levels, and a greater risk of heart
disease
Sexuality
Sexuality
• Most people in middle adulthood lead rich sex lives.
• Gradual decline in the frequency of sex
– Women aged 50-59 highest group not having sex
• Most common problem of women is
– lack of sexual desire and difficulty becoming sexually aroused
• Most common problem of men is
– erectile dysfunction
• Incidence of problems increase with age
Menopause, Perimenopause, and the
Climacteric
• Menopause
–
–
–
–
Cessation of menstruation
Normal process occurring between ages of 46 and 50
Lasts about 2 years
Can begin any time between 35 and 60
• Perimenopause
– Beginning of menopause characterized by 3 to 11 months of
amenorrhea (lack of menstruation)
– Deficit in estrogen may result in hot flashes alternating with cold
sweats
• Climacteric (critical period)
– Refers to gradual decline in the reproductive activity of the
ovaries
– Menstrual cycles become more erratic
Menopause, Perimenopause, and the
Climacteric (cont’d)
• Some women feel sexually liberated following
menopause due to separation of sex and reproduction
• Menopausal women may have sleep issues.
• Estrogen deficiency has psychological effects.
– Long-term estrogen deficiency has been linked to brittleness and
porosity of the bones
• Osteoporosis
– Bones break easily
– May result in serious fractures, can be life threatening
Hormone Replacement Therapy
• Hormone replacement therapy (HRT)
– Effective for some women
– Results of safety of use are inconclusive
– Some women increase risk of breast cancer, strokes, and blood
clots due to exposure to a combination of estrogen and progestin
• Selective serotonin reuptake inhibitors (SSRIs) help with
menopause.
Sexual Dysfunctions
• Sexual dysfunctions
– Persistent or recurrent problems in becoming sexually aroused
or reaching orgasm
• Women report
– more painful sex, lack of pleasure, inability to reach orgasm, and
lack of desire
• Men more likely to report
– reaching orgasm too soon (“premature ejaculation”), which is
more common in early adulthood
– lack of interest in sex and erectile dysfunction (more common in
men in middle adulthood)
Sexual Dysfunctions (cont’d)
• Lack of desire usually limited to one partner
– Sex therapists recommend trying to compromise and/or
resolving problems that may be affecting their sexual
relationship
• Erectile dysfunction
– Characterized by persistent difficulty in achieving or maintaining
an erection sufficient to allow the completion of sexual activity
– Incidence increases with age
– Makes men anxious when sexual opportunity arises because
they expect failure instead of pleasure
– As a result, sex may be avoided
– Partner may be frustrated as well
Sexual Dysfunctions (cont’d)
• Reduction in testosterone levels as well as medication may be
contributing factor to lack of sexual desire in men
• Medical conditions that affect sexual response include
– heart disease, diabetes, multiple sclerosis, spinal-cord injuries,
complications from surgery, hormonal problems, medications for
hypertension, and mental disorders
• Erectile problems can arise when clogged or narrow arteries
leading to the penis deprive the penis of oxygen.
Sexual Dysfunctions (cont’d)
• Perimenopausal and postmenopausal women usually
– produce less vaginal lubrication than younger women, and the
vaginal walls thin, changes which can cause sex to be painful
– artificial lubrication can help supplement the woman’s own
production
• Physical changes can produce performance anxiety and
discourage both partners from sexual relations.
• Exercise appears to ward off erectile dysfunction.
– Medications such as Viagra help
• The sexual relationship is usually representative of other
facets of the relationship.
Cognitive Development
Cognitive Development
• Verbal ability maintains stability as we age.
• Timed performance decreases as we age.
Changes in Intellectual Abilities
• Intellectual development during middle adulthood
demonstrates multidirectionality, interindividual
variability, and plasticity.
• Multidirectionality
– Some aspects of intellectual functioning improves while others
remain stable or decline.
• Interindividual variability
– People mature differently due to different cultural and social
settings.
• Plasticity
– Intellectual abilities are not fixed but can be modified under
certain conditions at almost any time in life.
Cohort Effects
• Research conducted by Schaie (Charness & Schaie,
2003) indicates
– intellectual functioning of the members of a society reflects the
technology and social functioning of that society.
– people in one cohort will perform better or worse in particular
areas than people who are from a different age cohort.
Fig. 15-5, p. 322
Crystallized Intelligence versus Fluid
Intelligence
• Crystallized intelligence
– Cluster of knowledge and skills that depend on accumulated
information and experience, awareness of social conventions,
and the capacity to make good decisions and judgments
– Includes specialized knowledge in a field
– Increases with age
• Fluid intelligence
– Person’s skills at processing information
– Refers to the speed of processing or analyzing information, the
ability to comprehend the relationships in visual stimuli
– Decreases with age
Crystallized Intelligence versus Fluid
Intelligence (cont’d)
• Conditions minimizing cognitive decline may include
– remaining healthy
– living in good conditions, such as decent housing
– remaining intellectually active by reading, lifelong learning, and
keeping up with current events
– being open to new ideas and new styles of life
– living with an intellectually stimulating partner
– being satisfied with what one has achieved in middle adulthood
or one’s most productive years
Information Processing: Speed of Information
Processing
• Information processing can be measured in reaction
time
– The amount of time it takes to respond to a stimulus
– People in middle adulthood have greater reaction time
• (Meaning slower) than young adults
– Only a fraction of a second
• Decline in speed may be due to changes in the integrity
of the nervous system
– Scientific research is inconclusive
Memory
• Most researchers conclude that people in middle and
late adulthood perform less well than young adults at
– memorizing lists of words, numbers, or passages
– rote rehearsal
• Less able to keep information in working memory long
enough to memorize it as we age
• Less capable of screening out distractions as we try to
focus on material as we age
• Elaborative rehearsal suffers as well because we are
less capable of classifying or categorizing quickly
Memory (cont’d)
• General knowledge is expanded during middle
adulthood due to interest in new areas.
• Procedural memory such as riding a bike or driving a
car can be maintained for a lifetime.
Expertise and Practical Problem Solving
• Expertise and practical problem solving increases with
age.
– due to social, emotional, professional experience
• Hiring a person in middle adulthood is beneficial.
– due to their greater store of expertise and practical problem
solving skills
• Once again, there is interindividual variation
Creativity and Learning
Creativity
• Many people at their height of creativity during middle
adulthood
• Difference in creativity in age can be found in creativity
in
– music, mathematics, and physics, with young adults surpassing
people in middle adulthood
• Writers and visual artists continue to improve into
middle adulthood, most emotional work tends to be at a
younger age
Mature Learners
• Learning possibilities affected by culture, social
structure, desire to learn
• Mature learners
– are highly motivated and more likely than younger learners to
find the subject interesting for its own sake (great
interindividuation in learning)
• Women with the greatest demands on them from family
and work are most likely to return to school.
– Need emotional and professional support