Writing

Reflect back upon your brainstorming from Week One and choose two events that had a significantly positive impact on your life. (Daughters Birth and Daughter highschool graduation)

Explain why you selected these two experiences/events from your list.
Determine the influence of Bronfenbrenner’s rings on each experience.
Analyze how learning from these experiences reinforced behaviors that are evident in your adulthood.
Assess the impact of these experiences on your online learning.

This assignment must be approximately two pages in length (not including the reference page), double spaced, written in Times New Roman 12-pt. font, and submitted as a Microsoft Word document using the Assignment Submission button. Use Adult Development and Learning as your primary source for this discussion, and support your work with at least two in-text citations from the course textbook within the body of your paper. Include both title and reference pages that are properly formatted according to APA Style as outlined in the

Ashford Writing Center

. Reference page should reflect complete reference from the course textbook

Chapter Outline

Blend Images/SuperStock

Learning Objectives

After studying this chapter, you should
be able to do the following:

1. Identify the key behavioral theorists and their
contributions to psychology.

2. Employ key principles of classical conditioning,
including an unconditioned stimulus, an uncon-
ditioned response, a conditioned stimulus, a
conditioned response, and a neutral stimulus.

3. Summarize the conditioning experiment
involving Little Albert; explain its relationship
to counterconditioning.

4. Compare and contrast classical conditioning
and operant conditioning.

5. Illustrate the shaping process.

Learning and Cognition 3

Introduction

3.1 Introduction to Behaviorism: Pavlov and
Classical Conditioning

• Ivan Pavlov
• Classical Conditioning
• Stimulus Generalization and Stimulus

Discrimination
• Extinction
• Conditioning Attitude

3.2 John Watson
• Conclusions
• Ethical Considerations

3.3 Counterconditioning

3.4 B. F. Skinner and Operant Conditioning
• Shaping
• Autoshaping

3.5 Cognitive Theory
• Postformal Thought
• William Perry
• Reflective Judgment Model
• Logic and Emotion

3.6 Schaie’s Stage Theory of Cognitive
Development

3.7 Executive Function

3.8 Other Kinds of Learning
• Priming
• Latent Learning

Chapter Summary

6. Assess the strengths and weaknesses of adult cognitive theories.

7. Apply Schaie’s stage theory to adult cognitive development.

8. Explain how executive function represents growth in cognitive development.

9. Recognize the relationship between priming and latent learning to memory and cognition.

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CHAPTER 3Introduction

Introduction: What Is Learning?

When people initially try to define what learning is, they usually focus on acquired knowledge or a specific skill. A student
can learn a list of state capitals; I can learn to count
in a new language; you are learning about psychol-
ogy right now. You may not first think of walking,
discovering visual perspective, or making friends
as learning processes, but they too are all forms of
learning. Psychologists define learning as a relatively
permanent change in behavior that occurs due to
experience or practice. In the broadest sense, you
can learn to play a musical instrument or how to add
numbers, but learning also takes place when people
turn their eyes away from the sun, take a second bite
of tasty food, and hold a phone to one ear instead of
the other.

There are many kinds of learning. Behavioral per-
spectives are popularly regarded as those that teach
people (and animals) how to act. Social cognitive
learning allows people to learn by watching others and recreating what they have observed.
Cognitively, learning can occur in relatively simple ways when someone reads information then
remembers it. However, it can also occur when observing an abusive parent or mentally solving
a problem. In the first part of this chapter, we will explore these fundamental approaches to psy-
chology from both a historical and an applied perspective. Later, the focus will shift to integrate
these traditional theories with contemporary models of adult cognitive development.

Blend Images/SuperStock

Learning continues throughout all stages of
human development.

Using Psychology to Inform Learning: Andragogy

Major proponents of adult education believe that adults learn differently from children. Malcolm
Knowles, a famous North American adult educator, is well-known for his theoretical approach
towards adult learning. Andragogy, or adult learning strategy, is grounded in psychological and
developmental assumptions that are unique to adult learners. Notice the theme of self-direction
and responsibility that runs through each of the assumptions (Knowles, 1970; 1984):

• Self-concept—Adults mature into a self-concept of accepting responsibility for
decisions, and choosing their own learning paths.

• Experience—Adult learners (as compared to children) have accumulated a wealth of
experience that contributes to learning activities.

• Motivation to learn—As adults mature, there is more intrinsic motivation to learn (i.e.
self-satisfaction) than extrinsic motivation (e.g. higher salary).

(continued)

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CHAPTER 3Section 3.1 Introduction to Behaviorism: Pavlov and Classical Conditioning

3.1 Introduction to Behaviorism: Pavlov and
Classical Conditioning

Along with Freud and the attractiveness of the psychodynamic perspective, psychology continued its rise in prominence with the behaviorists, including Ivan Pavlov, John Wat-son, and B. F. Skinner. Contemporary developmentalists who strictly adhere to the behav-
ioral perspective reject the idea that people pass through universal stages. Instead, behaviorists
generally focus on actions that can be measured through contact with the environment. They
focus on certain principles, like rewarding and ignoring behavior according to the law of effect.
These principles can help explain why people choose particular friends and are motivated to pur-
sue specific interests.

Ivan Pavlov
The behavioral perspective has its origins in the work of Ivan Pavlov (1849–1936), who, though
technically not a psychologist, became an iconic figure in the advancement of psychological sci-
ence. Pavlov was a Russian physiologist who in 1904 won a Nobel Prize in medicine for his study of
digestion. He collected saliva by exposing dogs to food without allowing them to eat it. However,
just as pet owners know that the sound of a bag or can of food being opened will initiate a change
in behavior, Pavlov accidentally discovered that dogs salivated to objects and circumstances that
were associated with food, even though no food was present. Specifically, dogs began to salivate
when they heard familiar footsteps or observed white lab coats of the technicians that normally
delivered food.

Using Psychology to Inform Learning: Andragogy (continued)

• Application of Knowledge—Adults need to know how learning will apply to their life
situations before they become immersed in learning activities.

• Orientation to learning—Adult learning is problem-centered in that adults are
immediately ready to usefully apply learned concepts. School children’s learning, in
contrast, is subject-centered, in that learning is necessitated by preset subject matter.

Analyze Knowles’s assumptions and identify how they relate to your life as an adult learner. What
knowledge do you hope to gain as a college student? What drove you to seek knowledge? How
can your life experiences enrich discussions and assignments? What problems will the knowledge
you acquire help solve? What do you hope to achieve from your learning?

Knowles, M. (1970). The modern practice of adult education: Andragogy vs. pedagogy. New York: Association Press. Knowles, M. (1984). Andragogy in
action. San Francisco: Jossey-Bass

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CHAPTER 3Section 3.1 Introduction to Behaviorism: Pavlov and Classical Conditioning

For a number of years after his initial discovery, Pavlov conducted experiments in an extensive,
sound-controlled laboratory. The experiment for which he is most famous occurred when he pre-
sented food to a dog while ringing a bell. He learned that after a number of presentations of the
food plus the bell, the sound of the bell alone would produce salivation (Pavlov, 1927/2003). At
the time, Pavlov called this process learning through association, since dogs learned to associate
food with the sound of the bell. We refer to this learning process as conditioning.

Classical Conditioning
Psychologists now alternately refer to the way that Pavlov paired stimuli as both classical condi-
tioning and Pavlovian conditioning, which is a type of learning through association. Because Pav-
lov was primarily interested in physiology, the sole focus of classical conditioning is on automatic
processes like salivation, fear, and nausea—responses that the autonomic nervous system mostly
controls below the level of consciousness. In a laboratory, classical conditioning first begins with
a natural stimulus that leads to a natural (or reflexive) response. Examples of natural stimuli that
elicit natural responses include touch leading to a response of sexual arousal, a puff of air leading
to the response of blinking your eyes, and being scared or cold leading to the response of piloerec-
tion (or “goose bumps”).

In Pavlov’s experiment, when presented with the natural stimulus of meat, the dogs reflexively
salivated. The food-salivation association is unlearned, or unconditioned. Therefore, the meat is
an unconditioned stimulus (UCS), and salivation is an unconditioned response (UCR).

Pavlov’s second step was to introduce a neutral stimulus (NS), an object that normally elicits no
salivation response, like a bell. This NS was paired with the UCS (food) a number of times. The
dogs eventually associated the bell with the food. Then, whenever the bell was rung, the dogs sali-
vated. Because the dogs had learned that the bell meant “food is coming,” the previously neutral
bell became a conditioned stimulus (CS) (see Figure 3.1). Salivation is not a natural response to a
bell, so we call it a conditioned response (CR) in the dogs.

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CHAPTER 3Section 3.1 Introduction to Behaviorism: Pavlov and Classical Conditioning

Figure 3.1: Pavlovian conditioning

Before conditioning, the bell had no effect on the dogs’ behavior; it was a neutral stimulus. After it was
paired with food, an unconditioned stimulus, the buzzer alone elicited the conditioned response of
salivation.

Bell

BEFORE CONDITIONING

Food
UCR

Salivation

• elicits No response
(or neutral response)

• elicits

CS
Bell

AFTER CONDITIONING

CR
Salivation

• elicits
CS
Bell

CONDITIONING PROCESS
(REPEATED SIMULTANEOUS PAIRING)

+
UCS

Food
UCR

Salivation
• elicits

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CHAPTER 3Section 3.1 Introduction to Behaviorism: Pavlov and Classical Conditioning

Pavlov and his lab associates experimented with a number of different stimuli. For instance, his
original experiments used a musical metronome, a device used by musicians to keep a steady tem-
po. He later paired the scent of vanilla (NS) with lemon juice, which naturally caused salivation. Af-
ter the lemon juice was removed, the vanilla scent (CS) alone caused the salivation response (CR).
Further experiments using moving objects and shapes of different colors as the CS were similarly
successful in eliciting a CR (Pavlov, 1927/2003).

It generally took Pavlov’s dogs a number of pairings to learn the stimulus-response relationship.
But classical conditioning can occur with just one pairing too. A bite of food when you are particu-
larly hungry will be associated not only with the production of saliva but also with extra enjoy-
ment. It is the reason that food samples are commonplace in some food stores. The association
between a particular food and cessation of appetite strengthens as a function of hunger—the
hungrier one is, the more enjoyable the food becomes (Egerton et al., 2009).

Aversive Conditioning
People and animals also avoid situations due to classical conditioning. For instance, after a per-
son is robbed, the victim is usually apprehensive about revisiting the location where the incident
occurred. Animals at a game reserve often stay away from electrified fences after just one encoun-
ter; even though its new owners may be kind and gentle, a previously abused dog may cower at
the sight of any adult. When certain stimuli result in the avoidance of certain behaviors, we refer
to it as aversive conditioning.

Applications
Classical conditioning has tremendous practical value that helps to explain behavior. A teacher
who witnesses a child cringe or avoid eye contact when an adult approaches may suspect that
the child associates adults with fear, perhaps due to abuse. Classical conditioning explains why
many people forever avoid the last food item they consumed before vomiting due to the flu. The
food did not cause the vomiting, but it is nevertheless associated with nausea through classical
conditioning. The virus was an unconditioned stimulus (paired with the food item) that elicited
the unconditioned response of vomiting. Similarly, if wolves are (purposely) made sick from eating
mutton (meat from sheep), when they later encounter sheep, they will avoid them rather than
attack them. This knowledge assists ranchers and environmentalists in managing herds and preda-
tory animal populations (Gustafson, Garcia, Hawkins, & Rusiniak, 1974).

Responses to songs or photos are also classically conditioned. We may associate them with tender
emotions. Feeling apprehensive on encountering a smell of disinfectant may trigger a (perhaps
unconscious) reminder of a visit to the hospital. Nostalgia sometimes offers a bit of flavor to foods
that you otherwise might reject. Classical conditioning can even modify the immune system. Ader
and Cohen (1975) famously paired saccharin water with a drug that suppresses the immune sys-
tem in rats. Upon removal of the drug, the saccharin water alone produced immune suppression.
Coincidentally, like Pavlov’s, their discovery was accidental. And also like Pavlov’s, their findings led
to a surge of studies that demonstrated the effects of classical conditioning, this time in regards to
immune system functioning in animals (Kusnecov, King, & Husband, 1989; Miller & Cohen, 2001).

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CHAPTER 3Section 3.1 Introduction to Behaviorism: Pavlov and Classical Conditioning

Though potential clinical application of associative learning on immune functioning in humans
is still in its infancy, initial results appear promising. Possibilities include reducing negative side
effects of chemotherapy and strengthening immune responses (Pacheco-López, Niemi, Engler,
& Schedlowski, 2011). Just as there is strong evidence that stress suppresses immune function
and reduces resistance to infectious diseases (Glaser & Kiecolt-Glaser, 2005), perhaps we can
harness Pavlovian conditioning to increase immune responses during cold and flu season by con-
ditioning a flavored beverage—or even a song carried on a portable mp3 device—with a strong
immune response. Exploiting the placebo effect of these stimuli (“Drinking this liquid will help
you fight off the flu”) could provide further immune system enhancements (Enck, Benedetti, &
Schedlowski, 2008).

Using Psychology to Inform Learning: Classical Conditioning

There are all sorts of unconditioned stimulus-response relationships. Some involve voluntary
muscles, such as when you withdraw a hand due to an electrical shock or after contact with a hot
frying pan. Others involve emotions or involuntary processes like those related to the immune,
reproductive, digestive, or even visual system. For instance, normally, when you walk into a dark-
ened room, the pupils in your eyes dilate involuntary; when there is bright light they constrict.
Therefore, light is a UCS leading to pupil constriction, which is a UCR. Likewise, darkness is a UCS
for pupil dilation, which is the UCR.

Try duplicating an experiment suggested by Hock (2009). You can set up your own laboratory
and experience the involuntary Pavlovian conditioning process directly. You will need a room
that becomes completely dark when the light is switched off, a mirror, and a bell, loud clicker, or
other instrument that makes a distinctive sound. A bathroom without windows usually provides
an ideal setup.

Facing the mirror with the lights on, observe your pupils. Ring the bell (or other sound) and then
immediately turn off the lights. The room should be completely dark. Wait about 15 seconds (do
not use a timer!) and turn the lights back on. Wait another 15 seconds or so, ring the bell, and
turn the lights off. Repeat the process of (1) lights on, (2) bell, (3) lights off 15 to 20 times. When
you are ready, ring the bell and do not turn the lights off. Look closely in the mirror and you will
see your pupils dilate slightly. The previously neutral bell has become the CS leading to pupil dila-
tion, the CR.

Stimulus Generalization and Stimulus Discrimination
Pavlov discovered that similar stimuli would produce the same conditioned responses. For
instance, dogs responded the same to bells that were of different tones. Similarly, adults often
associate one physical trait with increased attractiveness. This tendency is called stimulus gen-
eralization. In another study based on Pavlov’s work, researchers conditioned dogs to salivate to
a circle (Shenger-Krestovnikova, 1921). They generalized the same response to an ellipse but not

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CHAPTER 3Section 3.1 Introduction to Behaviorism: Pavlov and Classical Conditioning

Extinction
Pavlov also experimented with removing the CR in the presence of the CS. After he rang the bell,
he did not present the dogs with food. After a number of trials, the strength of the salivation
response began to die out. This process is called extinction. Perhaps the dogs stopped salivating
because they learned that the bell meant “no food.” However, it is difficult to unlearn something,
and classical conditioning is no exception. When Pavlov presented the CS a number of weeks later
without the CR, the dogs again salivated. This time the CR (salivation) was weaker than when it
was first conditioned, and lasted for less time than the first phase of extinction. The restoration
of the CS–CR relationship is called spontaneous recovery, which demonstrates that the CR is not
completely gone from memory.

Spontaneous recovery occurs for many people when an image or circumstance brings forth
thoughts of a former relationship. The CS of a name, image, or event can reignite a CR of warm
feelings. This unrecognized association could lead people to make poor relationship decisions
when warm, classically conditioned feelings cloud cognitive assessment (see Psychology to Inform
Learning: Following Your Heart).

to a square shape. Therefore, though the square
stimulus had the same size and color characteris-
tics as the round shapes, dogs were able to learn
the difference between the two. This process is
called stimulus discrimination. It is the reason
that you can tell the difference between a cotton
sweater and one made of wool.

Further, if animal lovers experience warm feel-
ings for a small number of dog breeds, they have
generalized to some dogs but also discriminated
among different subspecies. Most people gener-
alize their fear of stinging flying insects to large
carpenter bees because they look like the stinging
variety of bees, though they are essentially harm-
less. A specific perfume might remind a person
of a past relationship (discrimination), while the
smell of any cigar might be reminiscent of a long
ago visit to a grandparent’s house (generalization).

Lisette Le Bon/SuperStock

A person who had a fearful encounter with
a dog might be conditioned to run away at
the sight of any dog. This response is called
stimulus generalization.

Think and Review:

How do stimulus generalization and stimulus discrimination apply in the assessment of teachers
and subjects in school?

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CHAPTER 3Section

3.2 John Watson

Using Psychology to Inform learning: Following Your Heart

Although it is common advice to “follow your heart” or “go with your gut,” this is not always good
advice. Though it is certainly appropriate to consider why you have a particular feeling about a
pending decision, normally you are better off making choices that are based on intellectual delib-
eration. It is a myth that the best decisions are always made by “going with your feelings.” Those
types of decisions can lead to unplanned pregnancies, spontaneously quitting jobs, remaining in
bad relationships, and other poorly planned activities that “feel good.” Feelings may be part of
the decision-making process, but the best outcomes usually originate with cognitive reflection.

Conditioning Attitude
Politicians, marketing professionals, media personalities, and others know that attitudes can be
classically conditioned as well. Advertisers pair cars and alcohol with sex, hoping that consumers
will get aroused at the thought of buying specific products. Lobbyists often associate political par-
ties and candidates with specific words, resulting in the public’s intense feelings toward politicians
that are largely impersonal. In addition, conditioning is largely responsible for the wide cultural
and regional variation in attitudes toward preferred foods as well as unfamiliar foods that are
sometimes considered repulsive.

Think and Review:

Describe the UCS, UCR , CS, and CR toward a former boyfriend or girlfriend who you meet up with
after a period of time away.

3.2 John Watson

Though Pavlov’s studies in classical conditioning set the foundation for behavioral explana-tions of development, John Watson (1878–1958) was instrumental in advancing psychology as a science. He created an academic environment that promoted the recording of quan-
tifiable behavior. Considered the father of behavioral psychology, Watson said that psychologists
should only study observable behaviors, like how long a person looks at an object, how many
calories someone consumes, or a person’s blood pressure.

Along with his assistant, Rosalie Rayner, Watson classically conditioned 11-month-old “Little
Albert” to fear a white rat (Watson & Rayner, 1920). In this experiment, Watson used a method
that would not be permitted today because of egregious ethical violations. He first brought a
white rat to Albert, who appeared to enjoy being exposed to it. When Albert later played with the
rat, Watson stood behind him and struck an iron bar with a hammer, making a loud sound (UCS)
that provoked fear (UCR) in the baby. Little Albert “jumped violently, fell forward and began to
whimper” after only two exposures (p. 4).

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CHAPTER 3Section

3.3 Counterconditioning

Think and Review:

How can principles of classical conditioning be used to explain why some adults are excited to be
around dogs and others fear them?

A week later, after another eight exposures, Albert began to cry the instant the rat was presented.
At that point, Watson and Raynor viewed the conditioning as complete. Albert was then alter-
nately exposed to the rat and then other furry and nonfurry objects. It was found that he consis-
tently generalized his fear to furry objects such as a seal-fur coat and a rabbit, but not to wooden
blocks. Had he also been afraid of the blocks it would have been concluded that he was afraid of
the laboratory rather than furry objects.

Conclusions
Watson decisively demonstrated that the association between a stimulus and a response governs
learning and that these associations are built through repetition. In a sharp rebuke of Freudian psy-
chology, Watson concluded that future therapy to uncover Albert’s fear of a seal-fur coat based on
Freud’s theory of the psychodynamic, “will probably tease from him the recital of a dream which
upon their analysis will show that Albert at three years of age attempted to play with the pubic
hair of the mother and was scolded violently for it” (Watson & Raynor, 1920, p. 14). Furthermore,
he remarked that we cannot account for emotional disturbances only by unconscious processes.
Watson and Raynor concluded that many phobias are probably the result of conditioning.

Ethical Considerations
Although it was reported that Watson’s original intent was to reverse the conditioning by replac-
ing the fear with something pleasant, it apparently never took place. For many years there was lit-
tle knowledge about what happened to the little boy. However, recent evidence strongly suggests
that Little Albert was quite ill as a child and died in 1925, 5 years after the original experiment
(Fridlund, Beck, Goldie, & Irons, 2012). It would never be acceptable today to traumatize anyone
in a psychological study as Watson and Raynor did. In order to prevent future ethical violations,
beginning in 1953, the American Psychological Association published an ethical code of conduct1,
which it most recently amended in 2010 (APA, 2010).

3.3 Counterconditioning

A few years after Watson and Raynor published their study, Mary Cover Jones, a student of Watson’s, wanted to further explore phobias. First, she conditioned “Little Peter” to fear a rabbit. Later, she placed the rabbit and Peter in opposite corners of a room. Peter
was then given food items that he particularly liked. Over several sessions, the rabbit was moved
closer and closer to Peter. Eventually, Peter associated pleasure (brought about by eating) with the
rabbit and no longer showed any fear in its presence (Jones, 1924).

1American Psychological Association. (2010a). Ethical principles of psychologists and code of conduct (2002, amended
June 1, 2010). Retrieved from http://www.apa.org/ethics/code/index.aspx

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http://www.apa.org/ethics/code/index.aspx

CHAPTER 3Section 3.3 Counterconditioning

This process of replacing an unpleasant response (like fear) with something pleasant (food, relax-
ation) is called counterconditioning. Counterconditioning has helped people lose weight, quit smok-
ing, improve social skills, and change other unwanted behaviors (Skinner, 1938; Skinner, 1957; Skin-
ner & Ferster, 1957). It is most often used in the treatment of anxiety and phobias. For instance,
associating a medical procedure with pleasant activities that are not compatible with anxiety can
been successful in preparing patients for unpleasant treatments (Slifer, Avis, & Frutchey, 2008).

Though Mary Cover Jones was perhaps the first to document the principles of countercondition-
ing, Joseph Wolpe (1969) was the first to popularize a general method for its use, which he called
systematic desensitization. The goal of systematic desensitization is to pair a fear response with
relaxation. There are three steps to systematic desensitization. First, individuals make a hierarchi-
cal list of 15–20 situations that evoke anxiety and fear. For instance, on a scale of 100, a person
who is fearful of dogs may rank a photo of a puppy as a 10, walking next to a fenced-in dog park a
60, and a barking dog running down the street at 90. The next step is to learn a specific relaxation
technique. Finally, beginning with less fearful situations and moving up the hierarchy, relaxation
is paired with anxiety-provoking events. Because the body cannot physiologically be both relaxed
and fearful, the relaxation response replaces the fear.

Using Psychology to Inform Learning: Applying Aversive Conditioning

Counterconditioning usually introduces a pleasant stimulus–response association. When an unpleas-
ant stimulus (punishment) is delivered instead, it is called aversive conditioning. Examples include
the tainted mutton for wolves, an angry stare, or burning your tongue on hot liquid. These stimuli
cause later avoidance behaviors. Other examples of aversive stimuli include mild electrical shocks
paired with cigarette smoking, and distasteful chemicals applied to fingernails to reduce nail-biting
behavior. Aversion therapy has been successfully used in the treatment of alcoholism too, usually
involving a drug that causes nausea when paired with alcohol (e.g., Wiens & Menustik, 1983).

A home remedy based on the same principles involves wearing a rubber band on your wrist.
Rather than applying an aversive stimulus to an unwanted behavior, though, it usually entails
responding to an unwanted thought, such as self-criticism or longing to reignite a destructive
relationship. To proceed, place a rubber band on your wrist in such a way that it is close to your
skin but not be so tight as to cut off circulation or leave a mark. When the intrusive thought
becomes conscious, snap the rubber band. The resulting sting is similar to an electric shock. The
goal is to eventually replace the intruding thought with the aversive stimulus (mild pain), and
avoid both. Even though you are consciously in control of the strength of the stimulus, it still
works. Though professional aversion therapy has sometimes been fraught with ethical complica-
tions (especially when prescribed for children), various forms of it have been used to treat eat-
ing disorders, relationship anxiety, and a number of mild psychological issues (Mastellone, 1974;
Abramson & Jones, 1981).

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CHAPTER 3Section

3.4 B. F. Skinner and Operant Conditioning

Pavlov provided behaviorism’s initial theoretical foundation, Watson expanded its applica-tion in psychology, and B. F. Skinner (1904–1990) became its strongest and best-known proponent. Skinner is considered one of the founders of modern psychology. His theory of
operant conditioning is one of the most influential theories in the history of psychology. Operant
conditioning is learning that occurs when consequences lead to changes in behavior. The conse-
quence can consist of either reinforcement or punishment, as introduced earlier.

In classical conditioning, a response is usually condi-
tioned to appear after the presentation of a stimu-
lus. In operant conditioning responses come first and
then reinforcement is delivered. Rather than forming
an association, in operant conditioning reward is the
motivating factor for behavior. A consequent smile
or attention can motivate people to raise a hand in
class. The reward of grades, a diploma, or a job can
all motivate students to perform well. So can the
promise of money. However, immediate rewards are
generally much more effective than delayed ones,
and so behavior theory is somewhat incomplete in
fully explaining the completion of long-term goals
like earning a diploma.

Recall that Edward Thorndike’s law of effect stated
that reinforced behaviors tend to be repeated, and
those that are not reinforced tend to die out. For
instance, if a student outlines the key points of a
chapter, feels good about learning new material,
then earns an A on the test, the good grade provides
reinforcement and makes it more likely that the stu-
dent will repeat the outlining behavior. When people
get paid for going to work, they are likely to continue
working. If soaking in a tub full of warm water gives
pleasure, you are likely to repeat that behavior too. On the other hand, if walking alone at night
makes you fearful, you are likely to avoid that behavior; if wearing a particular outfit causes physi-
cal or emotional discomfort, it is less likely to be worn again. Skinner called these responses oper-
ant behaviors because they occur when operating within the environment to produce a change.

BananaStock/Thinkstock

If raising your hand is greeted with attention
or praise, you are likely to repeat this
behavior.

Think and Review:

How can experiences be conditioned so that school-related activities have positive associations?

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CHAPTER 3Section 3.4 B. F. Skinner and Operant Conditioning

Shaping
One of Skinner’s key contributions concerns the process of shaping. It involves reinforcing succes-
sive approximations to a target behavior. For instance, service animals are trained to perform spe-
cific behaviors, but they cannot simply be rewarded for the final behavior. If a trainer is teaching a
dog to open a door, the dog first must turn toward the door, then approach it, then elevate, then
grab the handle, then pull it, then push against the door. With each successive event, the dog is
rewarded until the desired outcome is achieved. When children play “Hot–cold,” a game where an
adult tells them they are “getting warmer” or “getting colder” as they get closer to or farther from
a desired object, they are shaping behavior until the reward of discovery occurs. When adults are
lost in a shopping mall but get closer to their target with each successive inquiry or error, behavior
is being gradually shaped.

Skinner’s most famous invention was the Skinner box. Using scheduled rewards (usually food pel-
lets), Skinner easily trained pigeons to move or peck in specific ways, and rats learned to pull
levers. Rats are routinely trained to play basketball and engage in other behaviors for high school
projects. These principles of behavior continue to be the method of choice for animal trainers
(and parents) alike. (Videos of people training dogs through shaping and training rats to play bas-
ketball are easily found on YouTube.)

Shaping is also used in mental health treatment centers and with children who have behavioral
problems. For instance, in applied behavior analysis (ABA) children earn rewards when they engage
in prosocial behaviors (Johnston, Foxx, Jacobson, Green, & Mulick, 2006). It is a preferred method
of treatment to teach social skills to children with autism (see more at Autism Speaks). Though ABA
is more effective than other techniques, children with autism who are trained with ABA have a par-
ticularly difficult time generalizing learned behaviors from one situation to another. This finding has
led to controversy about whether failure in learning is due to an inherent lack of ability to general-

ize or whether professionals have just not found the
right intervention design (Arnold-Saritepe, Phillips,
Mudford, De Rozario, & Taylor, 2009). Lack of gener-
alization over a wide range of settings has led some
to question the applicability of strict behavioral meth-
ods in teaching (Reynolds & Fletcher-Janzen, 2007).

Sometimes, constant behavior reinforcement is ideal,
such as getting paid for each item sold or for each
hour worked. Other times, behaviors are strength-
ened when rewards are unpredictable. For instance,
we may meet flower deliveries with excitement
because they are relatively rare and unexpected.
If they were an everyday occurrence, they would
quickly become less interesting. People who become
addicted to gambling are always anticipating the next
pay off. The more unpredictable it is, the stronger the
urge to pursue it. Therefore, some situations are bet-
ter suited to continuous reinforcement, and others
are better suited for variable schedules. There is no
ideal schedule of reinforcement that can be general-
ized to all situations (Skinner, 1961).

Mimi Forsyth/age fotostock/SuperStock

With the use of a Skinner box, Skinner
showed that by rewarding successive
approximations, we can shape a desired
behavior.

mos85767_03_c03_057-082.indd 69 6/21/13 10:01 AM

https://www.youtube.com/watch%3Fv%3Dy10MTi2cL04

http://www.autismspeaks.org/what-autism/treatment/applied-behavior-analysis-aba

CHAPTER 3Section

3.5 Cognitive Theory

Think and Review:

Make a list of five noises that you hear at least occasionally, like a siren or a person yelling your
name. Decide whether your responses to those stimuli are conditioned classically or operantly.

Autoshaping
Skinner demonstrated that superstitious behavior might largely be the result of “random” shaping.
He found that pigeons would engage in any number of behaviors depending on when they were
reinforced. If a food pellet randomly appeared after pigeons made a turn to the right, then the
pigeons might turn to the right until another pellet appeared, again randomly. Each subsequent
pellet reinforced the rotating behavior, even though they were unconnected (Skinner, 1948).

People act the same way. They attribute causes to random events. If enough people walk under
enough ladders, at some point something bad will happen. These superstitious behaviors are
referred to as autoshaping because behavior is shaped automatically without anyone providing
specific reinforcement. Athletes are notoriously superstitious. They may randomly relate an out-
standing performance to all sorts of events, like looking in a particular direction toward the stands
or wearing a specific kind of underwear, hat, or jewelry. The coincidence did not cause the out-
standing performance, but their association causes superstition.

3.5 Cognitive Theory

Watson, Skinner, and other behaviorists were essential in elevating psychology to the respected science it is today. Consequently, learning theory has countless applica-tions in the advancement of skills and in the drive to change behavior. On the other
hand, behaviorists sometimes have a difficult time explaining some repeated behaviors. Domestic
abuse is one example. It is too simplistic to merely argue that a spouse is somehow reinforced
for remaining in an abusive relationship. Pain is a punishment and yet people continue to place
themselves in harm’s way. Perhaps, once again, the key to explaining how a person develops is
using an interactionist perspective. Each perspective adds another piece of information that can
more fully explain behavior.

While learning theory has remained essential in understanding how humans and other organisms
learn, another movement became focused on how the mind processes information. Cognitive
psychology became a prominent subdiscipline of psychology beginning in the 1960s. With the
advent of the computer, psychologists became interested in how those “thinking processes” took
place—in both the mechanical and human machines.

Traditional cognitive theories of development begin with Piaget, a stage theorist who described
four kinds of cognitive change. Because he theorized the stages as distinct, they provide a good
example of discontinuous development. Piaget felt that cognitive processes reach their high-
est level of sophistication sometime during early adolescence. Although Piaget acknowledged

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CHAPTER 3Section 3.5 Cognitive Theory

that adults absorb greater quantities of information as they age, especially in specific areas
that are relevant to their lives, he theorized that adult thinking does not qualitatively change
after adolescence.

Modern psychologists who study adult development do not disagree with Piaget as much as they
extend his theory. Since Piaget’s theory ends with formal operations, it makes sense that some
theorists refer to further sophistication in thinking as postformal. Many alternative models express
differences as a qualitative change. On the other hand, information-processing theory describes a
more gradual quantitative change in thinking that occurs throughout the lifespan. We will explore
these perspectives next.

Postformal Thought
During adolescence, deductive reasoning emerges and provides solutions based on logic. Beliefs
need little justification if they are based on experts or personal experience. And because reason-
ing is based on logic and experience, there are few gray areas. On the other hand, adult thinkers
understand that logic cannot always provide absolute answers. Decision making is more nuanced,
and correct solutions can vary from one situation to another (Sinnott, 1998). In this kind of post-
formal thought, adults increasingly engage in more complex reflective thought.

For example, there is much debate in the criminal justice system about whether or not minors
who commit violent crimes should be charged as adults. Adolescents tend to think in absolutes,
such as, “He knew what he was doing; he should be tried as an adult.” Although legal guidelines
exist, court officers, judges, and attorneys take multiple factors into account when deciding to try
young offenders as juveniles or adults. Subjective factors like emotions and beliefs influence their
thinking. This kind of sophistication is a qualitative change from Piaget’s last stage. Rather than
only one answer being possible, individuals recognize that even people with different ideas can be
right about the same question, depending on the situation (King & Kitchener, 2004a). Numerous
studies have found that while adolescents use limited information to support narrow conclusions,
adults take more factors into consideration.

William Perry
William Perry (1999) concluded that early adulthood is a time when understanding of the world
begins to change. After studying the intellectual and moral growth of college students, he argued
that entering freshmen tend to use dualistic thinking. That is, they view the world in polarities
of right/wrong, for/against, and good/bad with little middle ground. This type of rigid, absolutist
thinking relies on authorities for answers, including books, professors, and other experts. During
college (and adulthood in general), people begin to use more reflective, relativistic thinking, as
adults realize there are fewer absolutes and multiple perspectives.

Perry found that cognitively mature students begin to trust their own sense of expertise when
they were able to develop it logically. Students move from seeing a world marked by absolute stan-
dards and values to one where diverse societies, cultures, and values could be endorsed equally.
It is difficult to recognize whether changes are due to natural maturation or, since Perry studied
college students, whether the environment specifically prescribed the changes he identified. His
conclusions may not apply to a broader population. On the other hand, his college students may
indeed have been more cognitively sophisticated.

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CHAPTER 3Section 3.5 Cognitive Theory

Reflective Judgment Model
Like Perry’s findings, the reflective judgment model proposes that there are distinct stages of
postformal cognitive development. According to this model, reasoning goes beyond logic and
occurs in three graduated levels, each with two or three substages (King & Kitchener, 2004b). In
the first stage of prereflective thinking, individuals can glean knowledge with certainty. A state-
ment that characterizes this level is, “As long as information is heard from a respected professor
or a popular news site, it must be true.” At this level there is usually an inability to recognize that
two points of view may be equally logical.

Next comes quasi-reflective thinking. At this level, knowledge is not always certain, but that is
because there is missing evidence. In education, students learn that knowledge is subjective.
Therefore people are entitled to their own views, and judgments should be withheld. Statements
that are typical of this level include, “I would embrace Erikson’s theory more completely if you
could show me concrete evidence.” A higher stage of this level might be, “Perhaps both Freud and
the behaviorists were correct about phobias, but they just use different evidence.”

During the last level of reflective thinking, knowledge may be uncertain, but individuals can still
make reasonable judgments with critical inquiry and synthesis of ideas. There are “degrees of
sureness.” People gather evidence and opinion and take a reasoned, personal stance. A typical
example is, “There is substantial evidence to support the view that sexuality is determined at
birth. Therefore, society should treat sexual orientation as a continuum of behavior, with all orien-
tations equally respected.” Like the first level, students hold firm convictions, but they are based
on sound reflection.

Although not universally accepted, evidence indicates that qualitative changes in cognition do
begin sometime during early adulthood (Sinnot, 2009). Students generally move from a position
of absolutes to nonjudgmental acceptance of multiple solutions. Various studies have found that
as educational level increases, so does this kind of reflective judgment (Brabeck, 1984; Fried-
man, 2004; King & Kitchener, 1994; King, Kitchener, Davison, Parker, & Wood, 1983). Teachers
are increasingly incorporating these teaching standards into classroom education (Friedman &
Schoen, 2009).

Evaluation of Reflective and Relativistic Thought
While the ability to engage in reflective thought might signify cognitive sophistication, some would
question the stipulation that nonjudgmental responses are inherently better than true right and
wrong. For instance, to suggest that one culture is “better” than another would probably be met
with gasps in a college community, especially among experienced students. Reflective thought
assumes one has achieved a higher level of development to be able to make multiple judgments
(leading perhaps to a nonjudgment) about any one culture. To be able to see the good and bad
of all cultures is to understand nuanced decision making. However, what about a culture in which
women are subordinated and children are exploited, or where education, social movement, and
independence are restricted? It is safe to say from an academic standpoint that a culture that sup-
ports equality for everyone is inherently better than those that are racist, sexist or engage in other
forms of institutionalized discrimination or oppression. This conclusion is contrary to higher-level
reflective thought and relativistic thinking.

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CHAPTER 3Section 3.5 Cognitive Theory

Another example concerns values in college education. Professors generally have a reputation
for espousing specific political beliefs (in both directions), a finding that has remained relatively
consistent for many decades (e.g., Allgood, Bosshardt, van der Klaauw, & Watts, 2010; Eitzen &
Maranell, 1968; Guimond & Palmer, 1996). Professors support positions both implicitly and explic-
itly when, according to the reflective judgment model, young adults are particularly vulnerable to
manipulation. Therefore, it would seem that students in college would exit with an appreciation
for both sides of the political spectrum, rather than the more typical outcome of becoming more
polarized (Hastie, 2007).

Using Psychology to Inform Learning: Making Judgments

The push to raise levels of reflective judgment assumes that most controversies have multiple
solutions, each equally important. It follows that making absolute judgments is most often taboo.
However, people constantly make judgments, as doing so is a survival mechanism. Every day you
embrace friends and avoid people who might be harmful. These are judgments that you make,
and it is okay to do this. The problem occurs when you prejudge (where the word “prejudice”
comes from) based on incomplete information. Though a fine line sometimes exists between bias
and sound decision making, judgment itself is not a taboo concept.

Logic and Emotion
In addition to understanding multiple points of view, we characterize adult thinking by the grad-
ual integration of emotion and pragmatism in the place of strict rules of logic, as in the juvenile
offender example mentioned earlier (Labouvie-Vief, Grühn, & Studer, 2010). Furthermore, there is
an increased tolerance for ambiguity and potential compromise. Mature thinkers tend to analyze
situations and make decisions on the basis of realistic and emotional grounds, recognizing that the
most practical solutions often involve compromise and a willingness to accept different thinking in
different situations (Jain & Labouvie-Vief, 2010).

These cognitive shifts are apparent when researchers study how people of different ages manage
social dilemmas. In one study, researchers presented high school students, college students, and
middle-aged adults with three different dilemmas. The first was about a past conflict between two
fictitious countries and had little emotional charge. The second concerned a family disagreement
about a visit to the grandparent’s house and was more strongly charged. The last strongly charged
dilemma involved an unwanted pregnancy between a couple that had opposing views on abortion
(Blanchard-Fields, 1986).

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CHAPTER 3Section

3.6 Schaie’s Stage Theory of Cognitive Development

Figure 3.2: Effect of age
and emotion on reasoning

Blanchard-Fields showed that little
difference existed in reasoning
ability (probed reasoning) between
adolescents and adults when there
was an absence of emotional content.
However, when the dilemma was
emotionally charged, adults showed
more cognitive sophistication.

Source: Blanchard-Fields, F. (1986). Reasoning on social
dilemmas varying in emotional saliency. Psychology and

Aging, 1, 325–333. Copyright .1986 by the American
Psychological Association. Reprinted with permission.

2.5

3.0

3.5

Age Group

P
ro

b
e
d

R
e
a
s
o

n
in

g
Livia task
“Visit” story
Pregnancy dilemma

Adolescents Young adults Middle adults

4.0

In the first scenario, when there was not much emotional content, the level of reasoning between
adolescents and young adults was similar. However, in the other two more emotionally charged
situations, both groups of adults used better reasoning processes than the adolescent group
(see Figure 3.2). This study famously demonstrated that maturity of emotions affects level of rea-
soning. Postformal adults gradually integrate emotions with cognition, supporting the idea that
adult cognition goes through qualitative change.

Think and Review:

In what way do these review questions facilitate postformal thought, as conceptualized by Perry
and others?

3.6 Schaie’s Stage Theory of Cognitive Development

Based on his work in the Seattle Longitudinal Study, Schaie specified an alternative stage model that goes beyond Piagetian formal operations (Schaie, 1977–1978). Rather than focusing on changes in the way adults understand information, Schaie used empirical data
from thousands of tests to focus on how adult use of information changes (see Figure 3.3). Before
adulthood, he noted that the main cognitive task is acquisition of knowledge. Hence, he uses the
term acquisitive stage to describe this process. During this stage, young people learn and store
information in order to prepare for the future.

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CHAPTER 3Section 3.6 Schaie’s Stage Theory of Cognitive Development

Next comes early adulthood, a time of transition, necessarily marked by increased efficiency. In
practical terms, a focused field of study replaces a liberal arts education. There is also a drive
toward independence because there is less parental and societal protection from errors in judg-
ment. Adults must therefore be fully competent to use their acquired knowledge. Schaie called
this period the achieving stage, which begins in the late teens to early twenties and is concerned
with finding orientations toward goals of independence. These include social goals like finding a
romantic partner and the right career.

Figure 3.3: Schaie’s stage theory of adult development

K. Warner Schaie suggested a stage theory of adult thinking that expands Piaget’s model beyond formal
operations.

Source: From Schaie, K. W. (1977-78). Toward a stage theory of adult cognitive development. The International Journal of Aging, 8(2), 129–138. Republished with permission
from Baywood Publishing Company, Inc.; permission conveyed through Copyright Clearance Center, Inc.

Extending into middle adulthood is the responsible stage, which spans the late thirties to the
early sixties, and the executive stage that typically occurs during the thirties and forties. During
this period adults care for the needs of their families (responsible) and may give greater concern
to larger societal systems (executive). Individuals may become involved in community activities
and care for the world beyond themselves. The foundation for cognition occurs during acquisition
and achieving, but middle-age cognitive function is transformed. It matures into being more orga-
nized, integrated, and interpretive to meet increasing levels of demands.

The last stage begins in late adulthood. Older people tend to focus on activities that have particu-
lar interest. There is a transition from acquiring information to using information to streamlining
information. If there is no immediate use for information, it becomes less important. For instance,
after deciding they will never move residences again, older people may become less interested in
real estate values. Schaie called this final phase the reintegrative stage.

ACQUISITIVE

ACHIEVING

RESPONSIBLE

EXECUTIVE

REINTEGRATIVE

YOUNG
ADULTHOOD

MIDDLE
AGE

OLD AGECHILDHOOD
AND

ADOLESCENCE

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CHAPTER 3Section

3.7 Executive Function

Using Psychology to Inform Learning: Thinking About the Future

An important part of cognitive development in young adults revolves around developing the abil-
ity to rationally consider alternate futures for themselves. To make choices about future plans,
adolescents and young adults must project themselves into different roles that they might occupy.
Nonhypothetical thinking can sometimes lead to poor decision making. For instance, many young
teens (and older people too) romanticize child rearing. They look only at how cute little babies
are and how easy they are to feed, change, and put down to nap. And they are easy—as long
as you only see them temporarily. Mothers and fathers alike know that the reality of raising an
infant—including sleepless nights, exhausting days, financial responsibilities, and the difficulty of
simply taking a shower or running errands—is nothing like the projection that people sometimes
idealize. Only by developing the ability for deeper reasoning and seeing the world without “rose-
colored glasses” can adults make informed decisions about their futures.

Think and Review:

Reflect on and/or project into the future how you see yourself engaging in each of Schaie’s stages.
Think of concrete examples of how you would identify with each stage of development.

3.7 Executive Function

In contrast to stage theories, the information-processing model stresses that cognition becomes more complex as a function of gradual changes in the processing, use, and storage of infor-mation. As people mature, the brain continues to make more connections, increasing mem-
ory capacity by becoming physically more elaborate. The gradual physical changes coincide with
changes in the way people organize the world, solve problems, and ultimately take in and process
additional information. This increase in sophistication allows people to more efficiently manage
their own thinking and behavior, a process of self-regulation called executive function.

The executive system is theorized to be a kind of overseer to cognitive processes. For instance,
when deciding how to guess on a multiple-choice exam, students consciously analyze all the
possible answers. That is, there is consideration of why each possibility might be correct or not,
based on the instructor’s lectures, attitudes, a mass email, or what the students have heard in
the past. This kind of “thinking about thinking” is called metacognition. It involves the ability to
plan, hypothesize about possible outcomes, and make reasonable informed decisions regarding
cognitive–behavioral strategies (Flavell, 1976). You engage in metacognitive processes when you
actively plan a daily schedule while thinking about your different obligations and time commit-
ments. Metacognitive processes also occur while balancing a chemistry equation or comparing
psychological theories. There is constant planning and evaluation. Pieces of information often
occupy consciousness while a search for complementary parts goes on simultaneously.

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CHAPTER 3Section 3.7 Executive Function

Using Psychology to Inform Learning: Self-Regulation

Understanding your limits of attention is also part of self-regulation. Activities like attending to a
lecture or watching an uninteresting video take specific conscious effort; it is not always easy. If
you find yourself attending less intensely than you would like, it is important to understand how
to best exploit your own resources.

For students in a face-to-face class, many have found that sitting in the front row reduces dis-
tractions. Other students find that taking notes on everything helps them focus, whether they
are sleepy or not. Annotating texts or modules in an online classroom serves the same purpose.
When you assess your own ability to be distracted and actively improve your work habits, you
increase self-regulatory behavior. It is like consciously making a decision to move tempting cook-
ies from view—where you will be drawn to eat them whenever you pass by—to a pantry where
you will not see them. It is a metacognitive process because you are assessing your own knowl-
edge and experience while understanding hypothetical outcomes.

There is a significant increase in use of metacogni-
tive strategies during adolescence (Weil et al., 2013).
Adult learners continue to advance memory capac-
ity and become more proficient at estimating time
necessary to complete tasks, including reading and
preparing for an exam. Compared to their younger
counterparts, older students are generally better
at judging whether or not they have learned mate-
rial sufficiently, and hence are better able to com-
plete short-term educational goals. On average,
adults continually improve their ability to self-assess
strengths and weaknesses and revise goals. These
types of behaviors are powerful predictors of learn-
ing outcomes (Desoete, Roeyers, & DeClercq, 2003;
Veenman, Van Hout-Wolters, & Afflerback, 2006;
Wang, Haertel, & Walberg, 1990).

Executive functioning also includes self-regulation,
the ability to control emotions and behavior. It is
involved in the delay of gratification. For instance,
some people talk themselves through the process of
resisting warm bread placed on a table before a meal
(e.g., “I can have one piece; I really want to enjoy my
dinner without stuffing myself.”) Whenever a per-
son thinks twice about sending a potentially inflammatory email, there is an intentional part to
the thought process that oversees and directs the flow of information. In a learning environment,
experimental findings show that self-regulatory functions improve with age. It is likely that aging
and emotional regulation in general are positively correlated (Scheibe & Blanchard-Fields, 2009).

George Doyle/Stockbyte/Thinkstock

The ability to self-regulate emotions and
behaviors improves with age.

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CHAPTER 3Section

3.8 Other Kinds of Learning

Think and Review:

Explain how the concept of executive function can be applied to the Using Psychology to Inform
Learning features in this text.

3.8 Other Kinds of Learning

Sometimes learning does not fall neatly into one discipline or another. The way that observa-tion affects memory and subsequent behavior is the subject of two final types of learning that will be addressed here: priming and latent learning.
Priming
One of the more interesting questions that cognitive psychologists attempt to answer is how the
mind “sees” and organizes patterns based on experience. Priming effects occur when exposure

to one stimulus unintentionally affects perception
and recognition of another. This shows that the mind
is inherently biased. For example, in one study par-
ticipants were unknowingly exposed to words asso-
ciated with hostility (they were primed for hostility)
and then asked to describe the behavior of a neutral
person. After priming, the number of hostile words
participants had seen were positively associated
with the hostility ratings of the neutral person (Bargh
& Pietromonaco, 1982). Subtle visual cues therefore
prime the way we mentally represent information
and interpret behavior. Researchers have observed
this phenomenon in a wide range of social situations
(Bargh, 2006).

Performance on a task that has been primed can
improve or decline depending on the association
of the prime. Because sports drinks are associated
with persistence in athletics, being primed with them
has been found to increase performance compared
to viewing a bottle of water. We can affect athletic
achievement simply by being exposed to one bottle
or another while participating in a seemingly unre-
lated task (Friedman & Elliot, 2008). In another study,
older adults 60 to 90 years of age were primed to
activate stereotypes about aging (Levy, 1996). Partic-
ipants engaged in a standard priming task that asked
them to evaluate whether words that were quickly

iStockphoto/Thinkstock

Perceptions and experiences may be biased
depending on previous exposure to stimuli.
If you were primed for hostility, you are
more likely to describe this person as hostile
than if you were not.

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CHAPTER 3Section 3.8 Other Kinds of Learning

Using Psychology to Inform Learning: Priming

Some students often remark that multiple-choice items are “tricky,” yet others disagree about
the same exams. One reason is due to priming. Exams are written in such a way that students
are primed to answer incorrectly when the correct answer is unknown. That is, incorrect choices
consist of words and concepts to which you have been exposed, even if you do not consciously
recall it. If you guess at an incorrect answer because it “sounds” correct, chances are that you
were primed for it in some way. If you really know an answer, priming will not matter, because
you have conscious awareness of accuracy.

This idea also contributes to many students’ misperceptions of being a “poor test taker.”
Although some individuals have legitimate learning disabilities or perceptual issues that affect
performance, most people do not. It is rare that someone who truly knows the material con-
sistently underperforms on exams. Recognizing a number of terms on an exam is not the same
thing as integrating concepts. In the meantime, when students label themselves as poor test
takers, they can be priming themselves to underachieve. Conversely, establishing a more self-
affirming mindset (“I will do whatever it takes to learn this material!”) is likely to increase per-
formance (Wakslak & Trope, 2009). A focus on positivity has other benefits as well, and we will
explore this in upcoming chapters.

flashed (100–250 ms) on a computer screen were above or below a particular mark. The task
was only important in that it exposed participants to positive (e.g., “wisdom”) or negative (e.g.,
“senility”) words associated with aging. When positive stereotypes were activated, participants
improved on cognitive tasks like memory performance. On the other hand, when negative ste-
reotypes were primed, memory, self-efficacy, and self-perception of aging all declined. The same
changes in performance did not occur among similarly primed young adults, presumably because
the stereotypes did not apply to them. Similarly, being exposed to age stereotypes famously
caused research participants to walk slower when leaving an experimental lab (Bargh, Chen, &
Burrows, 1996).

Priming effects facilitate other stereotypes too, like those related to gender and race (e.g., Bargh
et al., 1996; Yao, Mahood, & Linz, 2010). Women have been found to put in reduced effort in
math when primed in the negative gender math stereotype (Jamieson & Harkins, 2012). People
can even be primed to act rudely. Researchers presented participants with words to unscramble
that were neutral, related to rudeness (e.g., “bother”), or related to politeness (e.g., “courteous”).
Unaware of how they were primed, 64% of the “rude” group but only 18% of the “polite” group
behaved rudely, as measured by willingness to interrupt. The neutral group was about midway
between the other two groups (Bargh et al., 1996).

These findings are used in consumer research as well. Shoppers will pay attention to different
characteristics of a product depending on the background features of a website. If, for example,
the background consists of graphics related to money, buyers will more closely consider the costs
of the product; if the background is associated with comfort, then search preferences change
toward comfort (Mandel & Johnson, 2002).

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CHAPTER 3Wrapping Up and Moving Ahead

Latent Learning
Priming research shows that in many cases we absorb stimuli without intending to or being rein-
forced for doing so. A procedure that introduced rats to three different maze conditions famously
demonstrated that information can be stored even though it is not demonstrated or initially rein-
forced (Tolman & Honzik, 1930). In the experiment, researchers placed three groups of rats in the
same maze. The first group was reinforced if they successfully made their way to the exit. Over
nine days, whenever they made it out of the maze, researchers placed them back in to attempt to
get out again.

Researchers allowed rats in the second group to run around the maze over nine days without any
reinforcement. If they exited the maze, the researchers simply placed them back in. However, on the
tenth day rats in this group were offered reinforcement if they escaped the maze. The third group
served as a control and never received any reinforcement. At the time of this experiment, behavior-
ism was proving to be a predictable science. Therefore, it would have been assumed that rats in the
first group would outperform the second group because learning is dependent on reinforcement.

Rats in the first group did indeed outperform the other two groups for nine days. However, on the
tenth day, when both the first and second groups received reinforcement, rats in the second group
that had never before been reinforced ended up solving the maze faster. They had apparently
constructed a cognitive map of the maze that allowed them to solve it almost immediately, even
though they were not being reinforced. The rats had acquired knowledge and formed memories
through a hidden process called latent learning.

This type of cognitive learning occurs when bus passengers learn how to get to a particular loca-
tion without ever being the driver. Learning occurs, but individuals do not demonstrate it until it
is reinforced. Parents learn to care for and discipline children in both explicit ways (books, con-
versations) and by latent learning. Parents may not realize they had gathered certain kinds of
knowledge until they use it later. During elementary school, future teachers learn many classroom
techniques that they do not usually demonstrate until they later become employed as adults.

Think and Review:

How does priming affect the way you might view support for educational achievement from
teachers, spouses, or parents?

Chapter Summary

Wrapping Up and Moving Ahead
Learning permeates all of psychology and human behavior. Psychology became the respected
science it is today beginning with the work of Pavlov, Watson, and Skinner. Because of this, we
understand how to shape both positive and negative behavioral outcomes. It is unquestionable
that conditioning influences adult behavior, including the choices you make every day. In addi-
tion, sometimes learning occurs strictly as a result of cognitive processes, even without conscious
awareness. Adult theories of cognitive development move beyond formal operations and usually
include a description of a transition from dualistic thinking to relativistic thinking.

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CHAPTER 3

Key Terms

Although the next chapter addresses the strong biological foundation that forms the basis for
much of adult development, keep in mind that there are many ways that we learn to change
outcomes.

Summary of Major Concepts
• The school of behaviorism grew out of the frustration that psychodynamics could not be

adequately tested.
• Ivan Pavlov, a physiologist, first demonstrated the conditioning process while collecting

saliva from dogs.
• Classical conditioning is a specific process whereby specific stimuli and responses can

be identified.
• Aversive conditioning is one of many ways that principles of classical conditioning can be

employed in practice.
• Stimulus generalization occurs when similar stimuli result in the same behavioral response.
• Stimulus discrimination occurs when different stimuli result in different behavioral

responses.
• John Watson and Rosalie Raynor famously conditioned “Little Albert” to be fearful of

rats and other furry stimuli.
• Mary Cover Jones was first to systematically record the process of counterconditioning.
• B. F. Skinner was perhaps the most influential early behaviorist. He developed extensive

laboratories to record and shape behavior. Skinner and Watson were instrumental in
promoting psychology as a science.

• Cognitive theory has expanded beyond the early ideas of Piaget to include conceptual-
izations of postformal thought.

• Models of postformal thought often differentiate between the dualistic thinking, indicative
of adolescence, and the more cognitively advanced relativistic thought.

• K. Warner Schaie used data from the Seattle Longitudinal Study to outline a stage model
of cognition, which describes changes from childhood into old age.

• Executive function includes cognitive processes that are involved in self-regulation and
other aspects of executive management of thought. It includes metacognition, or thinking
about thinking.

• Priming and latent learning occur without the same kind of conscious attention that is
indicative of other types of cognition. Exposure to certain stimuli may enhance and bias
later memory for actions and perceptions.

Key Terms

autonomic nervous system Branch of the
nervous system that controls mostly auto-
matic processes like digestion, heartbeat, and
salivation.

autoshaping Behaviors that arise by random
reinforcement. Similar to superstitions.

aversive conditioning A previously neutral
stimulus is paired with a naturally aver-
sive stimulus to produce the same nega-
tive response once the natural stimulus is
removed.

B. F. Skinner An early proponent of behavior-
ism and its most famous figure.

classical conditioning A type of learning that
occurs when a previously neutral stimulus elic-
its a previously unassociated learned response.
Also known as Pavlovian conditioning.

conditioned response (CR) A learned
response as a result of a conditioned stimulus.

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CHAPTER 3Key Terms

conditioned stimulus (CS) Previously neutral
stimulus that now produces a conditioned
response.

counterconditioning The process of replac-
ing an unpleasant response with something
pleasant.

executive function An umbrella term that
encompasses processes of attention, self-
regulation, memory, problem solving, mental
organization, reasoning, metacognition, and
other cognitive tasks.

extinction The disappearance of a learned
response.

Ivan Pavlov Russian physiologist who acci-
dentally discovered the classical conditioning
process.

John Watson Instrumental in establishing the
field of behavioral psychology as a science.

latent learning Cognitive learning that occurs
without any reinforcement and is not demon-
strated until it is ready to be used.

learning A relatively permanent change in
behavior.

metacognition A part of executive function
that is like “thinking about thinking.”

neutral stimulus (NS) In classical conditioning,
a stimulus that has no response by itself; when
paired with an unconditioned stimulus, it later
elicits a conditioned response.

operant conditioning Learning that occurs
due to reinforcement or punishment.

Pavlovian conditioning See classical
conditioning.

postformal thought A broad term that
extends cognitive theory beyond formal
operations.

priming effects Occurs when exposure to one
stimulus unintentionally affects perception and
recognition of another.

reflective judgment model Cognitive model
that proposes distinct stages of postformal
thought.

schedule of reinforcement Describes varia-
tion in quantity or frequency of reinforcement.

self-regulation Ability to control one’s own
emotions and behavior.

shaping The reinforcement of a series
of behaviors that lead to a specific target
behavior.

Skinner box B. F. Skinner’s invention that
provided a laboratory to observe how animals
would respond to reinforcement.

spontaneous recovery The reemergence of a
previously extinguished response.

stimulus discrimination The tendency to
be able to distinguish between two different
stimuli.

stimulus generalization The tendency to
respond the same way when similar stimuli
are presented.

systematic desensitization A type of counter-
conditioning whereby a graduated hierarchy of
anxiety-producing stimuli are paired with relax-
ation to systematically diminish the anxiety.

unconditioned response (UCR) A reflexive
response that occurs naturally as a result of an
unconditioned stimulus.

unconditioned stimulus (UCS) A naturally
occurring stimulus that causes a reflexive
response.

mos85767_03_c03_057-082.indd 82 6/21/13 10:01 AM

Chapter Outline

iStockphoto/Thinkstock

Learning Objectives

After studying this chapter, you should
be able to do the following:

1. Examine contributing factors to longevity and
life expectancy and distinguish between them.

2. Identify and distinguish between theories of
primary aging.

3. Recognize visible changes that take place
during adulthood.

4. Appreciate changes in adult sexuality.

5. Describe adult changes in the primary senses.

6. Recognize common age-related diseases
and explain factors that contribute to their
development.

7. Explain the most common degenerative
diseases of the brain and distinguish
between them.

Physical Health
and Development

Introductio

4.1 Theories of Primary Aging
• Programmed Theories
• Damage Theories
• The Fountain of Youth?

4.2 Visible Changes in Adulthood
• Skin
• Hair
• Body Build, Bones, and Mobility
• Respiratory System

4.3 Sexual Changes
• Women
• Men
• Reproduction
• Desire

4.4 Changes in the Senses
• Vision
• Hearing
• Taste and Smell

4.5 Disease in Adulthood
• Sexually Transmitted Infections and Diseases
• Respiratory Disease
•

Osteoporosis

• Skin Cancer
• Diseases of the Cardiovascular System

4.6 Degenerative Diseases of the Brain
• Alzheimer’s Disease
• Parkinson’s Disease

Chapter Summary

mos85767_04_c04_083-108.indd 83 6/21/13 10:01 AM

CHAPTER 4Introduction

Figure 4.1: Life expectancy
by country

Life expectancy varies greatly among
regions of the world.

Source: Central Intelligence Agency. Country comparison:
Life expectancy at birth. The World Factbook. Retrieved
April 4, 2013, from Central Intelligence Agency website:

https://www.cia.gov/library/publications/the-world-factbook/
rankorder/2102rank.html

Introduction

We live in a time of great technological and scientific advancement, which has paved the way to discovering how to live more healthily and increase rates of survival. With an ideal medical and social environment, we can approach the maximum years that are
genetically programmed into our species. However, throughout the world there are also social and
lifestyle factors that impact the number of years we can expect any particular person to live. We
refer to this theoretical number as longevity. Biologically, the longevity of humans only changes
slightly over many thousands of years. There were very old people 2,000 years ago, and there are
very old people today, but we do not actually know how long the “perfect” body in the ideal envi-
ronment would live. The longest documented human lifespan was Jeanne Calment, who lived past
122, and many humans are living well past 110 years (GRG, 2012; Robine & Allard, 2003).

On the other hand, life expectancy is the average age of death for a specific population. When
infants die during childbirth, gang members die during adolescence, and older people die of natu-
ral causes, we include all of these when compiling an estimate of the average life expectancy in a
population. Modern sewer installations, understanding of germ theory, and use of antibiotics and
immunizations have all significantly contributed to increased life expectancy.

In addition, on average people live longer by avoiding dangerous habits and risky situations, like
smoking, drinking and driving, and engaging in unprotected sex. Circumstances are not always
avoidable, though. Worldwide, many infants are born into contaminated environments that cause
infections. The lack of medical care affects mortality rate (number of deaths) further. Many peo-
ple do not have the option of breathing smoke-free air. Individuals of all ages can be subjected to
civil unrest and war. Therefore, both personal and social activities affect average life expectancy
for a population, which we can define as a community in New Jersey or an entire country. The life
expectancy in Afghanistan and in many countries in war-torn Central and South Africa is estimated
to be less than 50 years. That figure differs greatly from the one in countries like Canada, Australia,
Italy, and Japan, where life expectancy exceeds 80. See Figure 4.1 for a comparison of life expec-
tancies between selected countries.

Country

Y
e
a
rs

U.
S.

In
di
a

In
do

ne
s

Ch
in
a

Br
az

M
on

ac
o

M
ex

ico

Ru
ss

Fr
an

Ja
pa

Ca
na

So
ut

h
Af

ric
a

Si
er

ra
L

eo
ne

M
al
i

78.49

49.41

56.55

53.06

83.91
81.4881.46

76.66

66.46

72.79

89.68

74.84

67.14

71.62

mos85767_04_c04_083-108.indd 84 6/21/13 10:01 AM

https://www.cia.gov/library/publications/the-world-factbook/rankorder/2102rank.html

http://www.grg.org/Adams/E.HTM

CHAPTER 4Section

4.1 Theories of Primary Aging

There are further differences among women and men. With only six exceptions (five of which are
in sub-Saharan Africa), in every country for which data are available, on average women outlive
men, often by a decade or more. In Monaco, for instance, life expectancy for men is nearly 86, but
for women it is almost 94. When life expectancy is significantly lower than the worldwide average,
the reasons are fairly obvious: War, AIDS, infant deaths, and childhood diseases claim many young
lives and devastate the population average. On the other hand, scientists are curious about the
differences that exist between those who live in large cities versus small towns, and what factors
contribute to differences in life expectancy among different countries like Mexico (77), Russia (66),
and France (81).

In the United States, research shows that Blacks, Hispanics, and those in lower income groups
have more chronic diseases, poorer health, and a lower life expectancy than those who are in
middle- and upper-income brackets. However, if instead people are divided simply into higher-and
lower-income brackets, racial differences disappear; income level is the most important factor
associated with health, not race (Guralnik, Land, Blazer, Fillenbaum, & Branch, 1993). Of course,
income is strongly associated with educational achievement as well, so income and education are
usually better predictors of secondary aging than racial variables.

Therefore, in general, both direct and indirect factors influence aging, and this is another issue
that we can relate to the difference between nature and nurture. Because longevity is governed
by principles of nature, primary aging refers to biological elements of development. It includes
natural processes such as the loss of muscle mass and deterioration of the senses. On the other
hand, life expectancy is closely aligned with environmental and social variables. Some aging pro-
cesses can be accelerated or delayed depending on lifestyle or unavoidable environmental condi-
tions, and hence contribute only indirectly as explained earlier. These factors, like a lack of exercise
or living next to raw sewage, contribute to secondary aging.

While this chapter will focus mostly on primary aging and its theories, it will become apparent that
we cannot always easily separate issues related to secondary aging. For instance, it is not uncom-
mon to have achy knees, shoulders, and wrists due strictly to age-related decline in the amount
of cushioning material in joints. But football players, workers who engage in repetitive tasks, and
others who experience physical trauma are likely to have exaggerated aging effects. So, before the
next chapter explores areas of development governed more by secondary aging, let’s take a look
at physical health and disease as they relate to primary aging.

4.1 Theories of Primary Aging

By understanding how primary aging takes place, biologists, psychologists, physicians, and others can promote the best possible outcomes for the aging population. Most theories fit into two main categories: programmed aging and damage theories. However, no theory
exists that adequately explains the limitations of the human lifespan, despite recent advances in
molecular biology and genetics (Kunlin, 2010). Furthermore, various theories may have complex
connections. Ultimately, an interactionist perspective may provide the best explanation for why
our bodies eventually give out.

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CHAPTER 4Section 4.1 Theories of Primary Aging

Programmed Theories
Programmed theories of aging suggest that there are biological and genetic limits to how long
we can live. Biochemical changes cause cells to weaken and become unstable. Specific genetic
programming may account for age-related conditions like some cancers and changes in memory
and psychosocial functions. People who live longer than others may inherit a cell structure that
has more potential to regenerate instead of self-destruct (Davidovic et al., 2010; Guarner & Rubio-
Ruiz, 2012). It is possible that hormones initiate the action of certain genes being switched on or
off, a process that epigenetics may also impact.

Another possibility is that the immune system is specifically programmed to become more vulner-
able to disease and hence promote mortality. Indeed, researchers have suggested that immunity
to disease peaks during adolescence, during which time (from an evolutionary perspective) we
have already been able to produce the next generation (Kunlin, 2010). Nevertheless, scientists
have failed to identify the mechanisms by which the destructive processes take place, nor do we
have a complete understanding of how they work. For instance, researchers have implicated age-
related weakening of the immune system in the onset of Alzheimer’s disease, but not in other
age-related conditions like osteoarthritis (Guarner & Rubio-Ruiz, 2012; Rozemuller, van Gool, &
Eikelenboom, 2005). And if the immune system were the primary mechanism that influences
aging, then it is likely that diseases would be more predictable than they are.

Damage Theories
There are a number of damage theories of aging
(also known as error theories), but they too have
limitations. The wear-and-tear theory makes intui-
tive sense, as it compares the body to a machine.
The more we use it, the more its “parts” deterio-
rate. Repeated use of knee and ankle joints causes
those areas to wear out. The number of older people
who have lost cartilage in their joints provides sup-
port for this theory. However, wear-and-tear theory
fails to explain why repeated use often has a positive
effect by maintaining flexibility and improving overall
health. Adults who more vigorously use their joints
through exercise generally outlive people who are
more sedentary, even when weight is controlled for
(Moore et al., 2012). Pulmonary (lungs) and cardiac
(heart) functions improve with more use as well.

One specific damage theory involves a type of by-
product that occurs as a result of normal cell metab-
olism. Free radicals are electrically charged chemi-
cals that build up as a normal part of cell production.
Free radicals are especially reactive to exposure to
modern-day toxins and everyday occurrences like sunlight, x-rays, pollution, and disease. Over a
lifetime, the cumulative effect of free radicals cause cells to deteriorate, malfunction, and become
susceptible to disease (Kunlin, 2010; Montine et al., 2011). Researchers have theorized that one

Fuse/Thinkstock

The poor long-term health of football
players is often attributed to the wear-
and-tear theory.

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CHAPTER 4Section

4.2 Visible Changes in Adulthood

way to stop this oxidative damage is to consume a diet that is rich in multiple types of antioxidants,
like berries, broccoli, red wine, and tea. In theory, antioxidants stop free radicals from doing dam-
age and hence slow the processes of primary aging (Brown, 2004; Joseph et al., 1999). Although
this theory makes intuitive sense, there are still significant challenges to accepting the idea that
limiting free-radical production is essential to reversing the aging process (e.g., Page et al., 2010).

The Fountain of Youth?
The evidence for free radical theory fuels the movement to reverse primary aging. In addition
to recommending the consumption of foods that contain antioxidants, another area of research
focuses on limiting calorie intake. If fewer calories are consumed, there is less cellular activity and
hence fewer toxic by-products. In a famous study of laboratory rats that researchers provided
with restricted, very low-calorie diets that contained all necessary nutrients, rats lived longer and
suffered far fewer diseases than their counterparts that consumed normal diets (McCay, Crowell,
& Maynard, 1935). Although this study is often used as a marker for what is possible, in general it
is probably not practical to suggest that people restrict their calorie intake by denying themselves
the everyday pleasure of eating.

Another alternative is to develop drugs that can mimic the effects of caloric restriction. As our
understanding of genetics has grown, scientists have identified more genes that are involved in
the self-destructive process (Cuervo, 2008). If drugs can stop the genes from behaving “naturally,”
they will slow the aging process. Furthermore, if genes that promote longevity by combating envi-
ronmental toxins continue to be identified, then they too can be exploited to keep people “young”
and healthy.

Think and Review:

Is it more important for you to delay the effects of primary aging (and to find the proverbial
“Fountain of Youth”) or to prevent the effects of secondary aging?

4.2 Visible Changes in Adulthood

Once we enter adulthood, observable changes begin to take place no matter what we do, beginning around age 30. Aging skin loses moisture and fats, making it dryer. It will even-tually become thinner, splotchy, and wrinkled. Hair turns gray and thins. We lose muscle
mass and strength, along with the ability to perform the same kinds of physical work. Coordina-
tion and balance become affected as well. Sight, smell, taste, and hearing all diminish. Many peo-
ple have achy joints, and bones may become thinner and weaker. These measureable changes are
all a normal part of biological aging, but that does not mean that the news is all bad. Importantly,
for the most part, the physical changes that begin in early adulthood do not become particularly
noticeable until middle adulthood. In addition, these physical changes are often accompanied by
peak psychosocial and cognitive development, often overshadowing and compensating for the
physical declines. Let’s look further at the larger changes that are more apparent than the changes
that happen within cells and genes.

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CHAPTER 4Section 4.2 Visible Changes in Adulthood

Skin
When people try to guess a person’s age, they often
look for the most visible signs—wrinkles, gray hair,
and, in men especially, hair loss. The same processes
that contribute to loss of blood vessels and muscle
mass also contribute to a gradual wrinkling of the
skin. The skin can be described in three layers, the
outer layer (epidermis) that serves mostly as a cover,
a middle layer (dermis), and an inner layer made up
of a large amount of fat. Unnoticeable at first, there
is a gradual loss of elasticity due to the skin’s loss of
collagen in the middle layer that provides strength
and flexibility. Without it, the skin sags. Oil glands
become less active, the layer of fat thins, and skin
cells do not hold as much water as before, creating
a dry feeling.

Later, the epidermis loses its structure, becomes
more transparent, and develops “age spots,” or
irregular areas of dark pigment. The thinning of the
skin also makes it more difficult for older people to
regulate temperature. Even though it may at first be
unnoticeable, smoking exacerbates the aging of the
skin. This phenomenon is especially apparent around

the mouth. Exposure to the ultraviolet rays of the sun (and artificial tanning lights) also accelerates
damage to the skin. Injury due to the sun is magnified in people with lighter skin, and a reduction
in pigmentation makes spots more visible (Rexbye et al, 2006).

Hair
If people live long enough, eventually hair thins and loses color, although there are tremendous
individual, sex, and racial differences (Tobin, Hordinsky, & Bernard, 2005; Van Neste & Tobin,
2004). Though hair appears gray, its hue comes from a mixture of natural pigmentation and the
lack of pigmentation; ultimately it loses all color and appears completely white. On average, Afri-
cans begin graying in their mid-forties, Asians in their late-thirties, and Whites in their mid-thirties.
On average, about 50% of people are 50% gray by 50 years old (Keough & Walsh, 1965).

About 95% of all men but only 20% of all women experience hair loss that is age related. Men tend
to lose hair more rapidly than women, including body hair. Additionally, during middle age both
men and women may begin to grow more hair in unwanted places. Men often grow hair inside the
ears and nose. Depending on individual hormonal changes, about 40% of women have a marked
increase in facial hair, most commonly on the chin and above the upper lip. From a psychosocial
perspective, women in both developed countries and those within emerging economies often
associate excess hair with a lack of femininity, which sometimes impacts confidence and self-
image. (Blume-Peytavi, 2011; Sundararaman, Shweta, & Sridhar, 2008).

The overall good news is that even though facial wrinkles and the loss and graying of hair are both
definitive visual markers for aging, there is virtually no relationship between them and mortality.

iStockphoto/Thinkstock

In later life, adults experience a loss of
elasticity in the skin, leading to wrinkling
and sagging.

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CHAPTER 4Section 4.2 Visible Changes in Adulthood

That is, when comparing people of the same ages who have wrinkles or hair loss versus those who
do not, there are no differences in longevity (Schnohr, Nyboe, Lange, & Jensen, 1998).

Body Build, Bones, and Mobility
In addition to sarcopenia, the gradual loss in muscle mass and strength that begins in the thirties,
the body undergoes a number of other changes in stature and composition. For instance, it is clear
that people shrink beginning in their fifties. On average, men lose one inch (3 cm) and women
nearly two inches (5 cm) before they are 70 years old. Over the next 15–20 years, the loss in stat-
ure is doubled (Sorkin, Muller, & Andres, 1999). A compression of bone in the spine, not the discs
as some believe, primarily causes the reduction in height (Bennani et al., 2009). In addition, condi-
tions like osteoporosis and Parkinson’s disease (discussed later in the chapter) can contribute to
even more extreme decreases in height.

On average, weight increases throughout middle adulthood, but it is difficult to know how much
is due to maturation and how much is due to lifestyle. We do know that the body naturally burns
less energy, and therefore requires fewer calories to maintain a stable weight, but adults also
become less active beginning very early in adulthood. If young adults do not exercise and adjust
calorie intake, there will be dual factors that contribute to weight gain. Men tend to put on weight
around the midsection, whereas women tend to accumulate fat in the hips. Adults can slow both
the increase in fat and decrease in muscle tone by performing more physical activity (Raguso et al.,
2006). In later adulthood, weight begins to decline due to hormonal changes that reduce appetite
and the signals that regulate hunger (Di Francesco et al., 2007).

Along with posture and bone health, managing sarcopenia is important in the drive for contin-
ued mobility and independence. Bones, ligaments, and tendons all begin a decline in efficiency
beginning in the late thirties to early forties. It is especially pronounced in athletes or others who
have experienced repeated trauma such as sprained ankles and knee injuries. Speed of walking
is a notable marker in two important ways. First, there is a gradual reduction in mobility, mirror-
ing the changes that sarcopenia and primary aging bring on (Shumway-Cook, 2007). But walking
speed also parallels an important part of lifespan changes: Although declines occur in most physi-
cal areas beginning in early adulthood, for the most part they are barely noticeable until middle
adulthood. That is, the typical person who is not a professional athlete does not notice a decline
in skills until middle adulthood even though physical changes began long ago. (This theme applies
to vision and other perceptual changes as well.) The best way to reduce the effects of sarcopenia
in adulthood is resistance training—at any age. As little as two to three times a week can have a
prolonged positive effect on strength and energy for tasks (Winett, Williams, & Davy, 2009).

Respiratory System
The key components of the respiratory system include the lungs and the muscles that control
breathing. In the same way that joints and muscles get stiffer with age, the rib cage and the effi-
ciency with which membranes transfer oxygen and carbon dioxide diminishes (Jett, 2011a). Among
people who do not smoke, the respiratory system remains fairly consistent with the amount of
physical activity that a person usually performs. That is, muscles and respiratory stamina have a
parallel decline; more lung capacity would not make a difference if muscles do not need extra
oxygen. Therefore, part of the developmental process of the respiratory system is under the same
kind of stresses as the rest of the body. The good news is that with regular exercise and limited
exposure to cigarette smoke and other toxins, it can remain fairly efficient well into middle age.

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http://www.nia.nih.gov/health/publication/exercise-physical-activity-your-everyday-guide-national-institute-aging/sample-0

CHAPTER 4Section

4.3 Sexual Changes

Hormonal changes that begin to occur in early adulthood influence sensitivity to some diseases. Hormones promote sexual characteristics, like body hair and breast develop-ment, and contribute to sexual arousal and regulation of the reproductive cycle. Men
and women both manufacture hormones involved in reproduction and sexuality, but they vary
considerably in their level of production. Each sex experiences specific kinds of hormonal changes,
which can have both a direct and indirect impact on energy, mood, cognition, and relationships.

Women
For women, the major change in middle adulthood is the loss of the ability to have children. It is a
gradual process that occurs over perhaps a 15-year span that is called perimenopause. In popular
vernacular, this time period is often referred to as menopause. However, menopause is techni-
cally a marker (a day, really) for when menstrual periods have stopped for one year. The average
age of menopause is 51, but there is wide variation (Minkin & Wright, 1997). It can occur as early
as 40 and as late as 60. During perimenopause, ovaries begin to produce far less of the hormones
estrogen and progesterone.

Like other midlife physical changes, women generally do not notice the transition into perimeno-
pause until well after its onset. During the last few years before menopause, it is normal for men-
strual cycles to become intermittent, corresponding to irregular hormone production. Sometimes
a month or more is skipped, other times perimenopausal women have two periods within a few
weeks. Rate of flow is similarly erratic.

Symptoms of perimenopause vary greatly, with just over 50% of women reporting they did
not experience the characteristic “hot flashes” that people often discuss (and associate with
erratic hormone changes); in general, the majority of women do not complain of serious symp-
toms (Rossi, 2004). Other women may experience fatigue, headaches, moodiness, sleep distur-
bances, or other symptoms (Lyndaker & Hulton, 2004). There is also evidence that perimeno-
pausal symptoms are modifiable. Women experience more severe symptoms when they smoke,
drink alcohol excessively, are depressed, or use oral contraceptives (Sabia, Fournier, Mesrine,
Boutron-Ruault, & Clavel-Chapelon, 2008). In addition, there are significant cultural differences.
For instance, Japanese women report substantially different behavioral effects of menopause
than do Western women, suggesting sociocultural factors are essential to understanding peri-
menopause (Lock, 1991).

Because the culprit for many women who experience symptoms appears to be the lack of normal
amounts of hormones, for many years doctors simply prescribed replacement hormones that
worked to relieve symptoms. This intervention is called hormone replacement therapy (HRT).

Think and Review:

According to the text, what is the difference between the physical changes that occur during early
adulthood and those that occur during middle adulthood?

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CHAPTER 4Section 4.3 Sexual Changes

However, in 1998 the Women’s Health Initiative released a study so striking that many in the medi-
cal community no longer supported HRT. The study found that the combination of estrogen and
progestin significantly increased a woman’s chances of a heart attack, stroke, blood clots, breast
cancer, and later dementia. Even additional estrogen alone (called estrogen replacement therapy,
or ERT) was related to increased chance of stroke and blood clots (NIH, 2007). A recent follow-up
upheld the earlier findings (Chlebowski et al., 2013).

There are newer medical alternatives to HRT, as
well as some untested homeopathic remedies.
For instance, there is some evidence that relax-
ation therapy and acupuncture reduce the fre-
quency of hot flashes (Zaborowska et al., 2007).
Like other preventive factors, regular exercise and
dietary supplements (often including calcium) are
essential components to a balanced treatment
program. In addition, social support helps to ame-
liorate emotional effects. Because of the constant
flow of new information, scientists recommend
that women consult with medical professionals
as well as do their own research1 before deciding
on any treatment protocol. Importantly, though
menopause is a major milestone for women both
physically and psychologically, many women wel-
come this change. One survey of women over age
50 found that women associate menopause with
many positive life changes, even among those
who had hysterectomies (surgery to remove the
uterus; Utian & Boggs, 1999).

Men
Men go though less dramatic changes than women do. There is a gradual decrease of about 1%
a year in the production of the hormone testosterone, starting in middle adulthood. The only
substantiated impact of this change is a very gradual reduction in sex drive (Stones & Stones,
2007). Like women, sexual activity for men can remain vibrant well into old age, despite the
decreasing hormone production. Testosterone replacement therapy can effectively treat some
symptoms of depression, fatigue, and lower sex drive that may be associated with reduced tes-
tosterone levels, but doctors do not indicate it as a general intervention. For the vast majority
of men who have low testosterone and no symptoms, doctors do not recommend treatment,
especially because there is a lack of long-term study of possible side effects (Bassil, Alkaade, &
Morley, 2009; Bhasin et al., 2010).

Unaccompanied by other medical conditions, lower testosterone does not usually cause erectile
dysfunction, which is the inability of males to achieve and maintain an erection. In a study of over
2,000 men at Johns Hopkins University, 18% said they had experienced erectile dysfunction at one
time or another (Selvin, Burnett, & Platz, 2007). Just over 5% of men between 20 and 40 years of

Fuse/Thinkstock

Social support helps women cope with
hormone changes they experience during
midlife.

1The National Aging Institute’s Web site (www.nia.nih.gov) is an institute of the NIH, a U.S. Federal Government agency that
provides accurate, up-to-date information about aspects of aging research, information about clinical trials, educational
materials and resources about aging for the general public, and information for researchers and health professionals.

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http://www.nia.nih.gov/health/publication/hormones-and-menopause

www.nia.nih.gov

CHAPTER 4Section 4.3 Sexual Changes

age reported it, and middle-aged men reported it about 15% of the time. Not surprisingly, erectile
dysfunction becomes more common as men age. Forty-four percent of men between 60 and 69
reported erectile dysfunction, which increased to 70% among men over 70 years old. A lack of
exercise, obesity, and smoking were all found to have a negative effect on the ability to achieve
and maintain an erection. A full 50% of men with diabetes reported this problem. Treatment for
erectile dysfunction is now centered on three similar drugs—sildenafil (Viagra), tadalafil (Cialis),
and vardenafil (Levitra)—which work by increasing blood flow to the penis. Research suggests that
all are highly effective in treating the problem (McCullough, Steidle, Klee, & Tseng, 2008).

During middle age, the prostate gland, a small gland under the bladder, often becomes enlarged.
As the prostate grows, it puts pressure on the urethra tube, squeezing it. Like squeezing a water
hose, this results in difficulty starting to urinate, an increased urge to urinate, and a slower stream
of urine. The prostate can become cancerous and can also contribute to bladder and kidney disor-
ders. About 10% of men in middle age have a recognizable enlargement and may seek treatment.
Medications include drugs that relax muscles around the bladder so that urinating is easier, as well
as enzyme inhibitors that shrink the gland.

Whereas prostrate surgery used to be fairly routine, “active surveillance,” or waiting while receiv-
ing regular medical care, is often the treatment of choice for low-risk cases of prostate cancer.
Recent statistical analyses show that on average surgery only extends life 1.8 months compared to
those who had regular medical follow-ups, and men who were on active surveillance enjoyed an
extra 6.4 years that were free of treatment (Brower, 2012). After 20 years, 2.8% of men on active
surveillance died of the disease compared to 1.6% of those who had surgery. However, the issue
of quality of life is significant. Some forms of treatment affect the ability to achieve and maintain
a functional erection in over 70% of men (Alemozaffar et al., 2011). Nevertheless, recent techno-
logical advances and strategic marketing (especially in relation to new surgery robotics) has driven
a renewed increase in surgical interventions (Cakarov, Yu, Desai, Penson & Gross, 2011).

Reproduction
As we have noted, hormonal changes affect sexual drive. It is estimated that women reach their
peak of sexual desire in their early thirties while men peak in their early twenties (Schmitt et al.,
2002). However, peak sexual desire does not coincide with peak fertility: the capacity to repro-
duce. Although in the United States there has been an upward trend in the age at which women
are first becoming parents, this pattern is contrary to the natural fertility peak, which occurs in
the early twenties (ESHRE Capri Workshop Group, 2005). Chances of becoming pregnant at age 40
are less than half of what they were at 20. Still, 44% of women become pregnant within of year
of having regular intercourse at age 40. Importantly, a woman’s advanced age carries a significant
risk of birth defects, including a high risk of chromosomal abnormalities.

In contrast to women, who experience a natural, biological limit to fertility, male reproductive
functions change only gradually during adulthood. Sperm production declines by about a third
up until age 60 and by half at age 80 (Whitbourne, 2002). Just as is the case with maternal age,
evidence indicates that paternal age is also an important factor in health outcomes of offspring.
Schizophrenia, Down syndrome, miscarriage, and other conditions are associated with paternal
age, perhaps due to reduced motility (self-propelled motion) or compromised integrity in the
structure of sperm (de la Rochebrochard & Thonneau, 2002; Fisch, et al., 2003; Sipos et al., 2004).
Most studies evaluating the reproductive impact of older fathers on children are confounded by
a number of factors, which make it difficult to attribute paternal age to outcomes. For example,

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http://diabetes.niddk.nih.gov/

CHAPTER 4Section

4.4 Changes in the Senses

rather than a direct deterioration of sperm, some researchers have suggested that increased
infections or the accumulation of toxins in the bodies of older men may have an indirect effect on
reproductive health (Sartorius & Nieschlag, 2010).

Desire
In general, during early adulthood, sexual desire peaks for both men and women, and the
awkwardness of adolescence gives way to more confidence and better communication. When
changes do occur, the majority of middle-aged adults still engage in sex at least a few times per
month. In fact, after menopause, many couples express a renewed interest in sex. Children have
left the house and the potential worry about becoming pregnant has passed (Greenberg, Bruess,
& Conklin, 2011). And contrary to the stereotype, adults continue to have sex well into old age
(Michael, Gagnon, Laumann, & Kolata, 1994). Sexual activity continues among the elderly world-
wide, including significant percentages that have intercourse multiple times per week (Nicolosi et
al., 2004). In a survey among adults in the United Kingdom, over 80% of adults 50 to 90 years old
reported that they remained sexually active (von Simson & Kulasegaram, 2012). Those findings
are consistent with other data as well. Only about 20% of seniors surveyed worldwide agreed with
the statement, “Older people no longer want sex;” the percentage was even lower in developed
countries. Overall, the strongest predictor for sexual activity in old age is the availability of a part-
ner and the frequency of sexual activity when younger (Mazo & Cardoso, 2011). That is, it appears
that the adage “use it or lose it” has some empirical truth.

Think and Review:

From an evolutionary perspective, why would fertility rates differ between men and women?

4.4 Changes in the Senses

Although senses begin to change during middle adulthood, with the exception of vision, it is not usually immediately apparent. Changes in smell, taste, audition (hearing), and senses related to skin pressure, pain, and temperature are not often noticeable until much later.
Vision
The decline in visual acuity usually becomes noticeable during the early forties. Presbyopia, the
loss of near vision, affects everyone before the age of 50. The lenses of the eyes—the tissue
responsible for focusing images—change shape and become less elastic. Muscle flexibility that we
need for focusing diminishes. Lenses become less transparent, so less light enters the eyes, result-
ing in more difficulty seeing in low-light conditions (such as reading menus in darkened restau-
rants). Adults in their early forties may not notice these age-related changes when in bright light
conditions, but eventually everyone needs corrective lenses when reading smaller print (Strenk,
Strenk, & Koretz, 2005).

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CHAPTER 4Section 4.4 Changes in the Senses

Figure 4.2:
Macular degeneration

A person with macular degeneration
might see the view of a street like this.

Source: .Joe McNally/Getty Images North America/
Getty Images

In addition to the normal changes of presbyopia, more than half of adults in the United States over
the age of 60 will develop a cataract, or a gradual clouding of the lens of the eye (Gohdes, Balam-
urugan, Larsen, & Maylahn, 2005). People with cataracts may have more difficulty viewing screen
media, reading, or driving. Lights may appear to have a halo around them. Worldwide, cataracts
are the leading cause of blindness, since they do not often receive treatment in the developing
world (WHO, 2012). In countries with available healthcare, surgery to remove the cloudy part of
the lens has become somewhat routine, and most patients report renewed eyesight and indepen-
dence within a week. Nevertheless, cataracts are still the second leading cause of blindness in the
United States. Although cataracts appear due to the effects of primary aging, secondary factors
like smoking, diabetes, and exposure to the ultraviolet rays of the sun can fuel their progression
(Mukesh et al., 2006).

The leading cause of blindness in the United States is age-related dry macular degeneration
(AMD). The macula is responsible for our sharpest central vision. With AMD, the macula becomes
dried out and thin, leading to deterioration in the middle of the visual field and a dramatic loss of
sharp vision, right where we most need it (see Figure 4.2). Everyday events like reading and imme-
diately recognizing faces or objects are particularly challenging activities. Scientists do not have a
clear idea of what causes AMD, how to prevent it, or how to cure it. It is most common in those
over 60 years old, and women are more likely to suffer from it than men.

Glaucoma also affects a significant proportion of the population. It occurs when increased pres-
sure in the eyeball leads to permanent damage to the nerve that sends visual signals to the brain.
In a way, the pressure in the eye squishes nerve impulses so that they no longer properly transmit
signals. The visual field of a person with glaucoma is a reversal of those with macular degenera-
tion—central vision is clear and peripheral vision is blurry. Although scientists do not completely
understand its causes, damage to the eye as a result of sports injuries or other traumas increases
its prevalence. If recognized early enough, doctors can usually treat glaucoma easily. They cannot
restore lost vision, but they can prevent further loss. Screening takes only a moment and consists
of a puff of air directed at the eye to measure pressure, in the same way that you would push on
a ball to check inflation pressure. Experts recommend yearly testing for glaucoma beginning at
age 40.

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CHAPTER 4Section 4.4 Changes in the Senses

Beginning in early adulthood, eyes also often develop floaters, particles from the inner lining of
the eye that float around in the liquid center of the eyeball. You may notice them while looking
at a white wall or at the blue sky. Floaters are sometimes annoying, but most often, they do not
impair vision.

Hearing
Environmental noise worsens hearing loss, especially among the generations who have been
exposed to years of loud music. The ability to clearly differentiate sounds (such as listening to one
voice in room full of people talking) begins to decline around age 50, likely due to changes in the
way the auditory nerve transmits to the brain. In addition, the ability to hear soft sounds, such as
a whisper, or higher frequency sounds, such as a birdcall, becomes more difficult. It is estimated
that 30% of all people over age 65 have significant hearing loss. If you have consistently listened
to very loud music, you almost certainly already have measureable hearing loss that is likely to get
worse with time. While hearing aids have improved tremendously in recent years, they are still far
from perfect in recreating unassisted hearing.

Taste and Smell
Perceiving taste and smell relies on the ability for neural receptors in the nose, mouth, and throat
to sense molecules. Chewing food activates these taste sensors, but the released aromas also
travel through a network that connects the top of the throat to the nose. Therefore, the smell
and taste receptors are both responsible for the perception of flavor. Although it is apparent that
these senses change with age, we currently do not have a great understanding of the processes
involved. Changes in taste may be due to a shrinking number of taste or odor receptors beginning
in early adulthood or the reduction of saliva that would otherwise release food molecules and
trigger flavor. People between 70 and 85 years of age have only about one third as many taste
buds as young adults (Moller, 2003).

These chemical senses also appear to be an important physical marker for Alzheimer’s disease,
a disease that impairs cognition in later adulthood. The first signs of the disease occur in various
areas of the brain that process information related to smell (Murphy, Solomon, Haase, Wang, &
Morgan, 2009). And abnormal behavior changes, such as reduced ability to identify specific odors,
coincide with the physiological changes in the brain. Researchers also associate the capability of
identifying odors with declines in memory for specific events and with cognitive impairment in
general. Furthermore, among individuals with specific genetic markers for Alzheimer’s disease,
impaired odor identification predicts later dementia, even when symptoms are not yet present
(Calhoun-Haney & Murphy, 2005; Wilson et al., 2009).

Think and Review:

Why do you think visual changes in adulthood are more noticeable than other sensory changes?

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CHAPTER 4Section

4.5 Disease in Adulthood

We generally consider early adulthood as one of the healthiest periods of life. High-risk physical behavior decreases somewhat, and the prevalence of diseases like certain cancers is decades away from peaking. Throughout adulthood the pattern of diseases
changes, including those that are sexually transmitted and others that are related to bone health
and dementia.

Sexually Transmitted Infections and Diseases
If untreated, infections that spread through sexual contact (sexually transmitted infections) even-
tually turn into diseases. Over 80% of sexually transmitted diseases (STDs) occur in the under-
25 population (CDC, 2011a). However, cases of sexually transmitted infections among individuals
between 50 and 90 more than doubled in the United Kingdom from 2000–2009, with similar
trends evident in the United States as well (CDC, 2011c HPA, 2010). Increased use of online dat-
ing sites among older adults, medications like Viagra, and more open attitudes toward sex among
baby boomers are possible contributors to this trend. (See Figure 4.3 for prevalence of common
STIs across the lifespan.) Bacterial infections like gonorrhea, syphilis, and the most common,
chlamydia, are usually easily cured with antibiotics. However, when left untreated, they can have
devastating effects. Infections in various reproductive organ parts in both men and women are
common; in the long term, infertility, blindness, and death can result.

0
5

P
e
rc

e
n

t
o

ll
R

e
p

o
rt

e
d

a
s
e
s

Gonorrhea
Chlamydia

27%

7%
9%

15%

32%

38%

17%

35%

Age
0–14 15–19 20–24 25–29 30–39 40+

Figure 4.3: Prevalence of
chlamydia and gonorrhea
by age group in the
United States

Adolescents and young adults represent
well over half of all sexually transmitted
diseases.

Source: Center for Disease Control and Prevention. (2013).
STD trends in the United States: 2011 national data for

chlamydia, gonorrhea, and syphilis. Retrieved from
http://www.cdc.gov/std/stats11/trends-2011

In contrast to short-term bacterial infections, viruses almost always have lifelong consequences.
They include genital herpes, the human papillomavirus (HPV), which can cause genital warts and
cervical cancer, and the human immunodeficiency virus (HIV), which is the virus that causes AIDS
(acquired immune deficiency syndrome). AIDS is a chronic, life-threatening disease that damages
the immune system, making a person less able to fight off a variety of illnesses and infections,
including pneumonia. The virus is transmitted from one infected person to another by sexual con-
tact (including oral sex), infected blood, sharing HIV-contaminated needles, and even from mother
to child—a tremendous problem in underdeveloped countries like many of those in Africa. HIV
does not spread through ordinary contact like shaking hands, hugging, or kissing.

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http://www.cdc.gov/std/chlamydia/stdfact-chlamydia.htm

http://www.cdc.gov/std/stats11/trends-2011

http://www.aids.gov/

CHAPTER 4Section 4.5 Disease in Adulthood

Due to large cultural and international differences, demographic issues are a prominent feature
of AIDS education and prevention. For example, because of increased education and awareness,
AIDS/HIV has dropped from the fifth to the 20th leading cause of death in the United States.
However, it remains the fourth leading cause of death among black women in the United States
between the ages of 25 and 55 and is the sixth leading cause of death worldwide (CDC, 2013;
WHO, 2011). In the United States, 20% of those infected with HIV are unaware that they are
infected, and half of those who are aware do not receive ongoing treatment (CDC, 2011b).

Unfortunately, many people still mistakenly think of AIDS as a disease that primarily affects homo-
sexual men. In fact, among the roughly 7,000 people who become infected daily throughout the
world, about half (48%) are women. AIDS remains especially entrenched as the leading cause of
death in sub-Saharan Africa, which is home to two thirds of the world’s HIV-infected population
(Kinney et al., 2010; Griffin, 2011). In Africa, about 42% of all new infections occur among young
people aged 15 to 24. An additional estimated 10% (about 3.4 million) are children under the age
of 15 that will soon be ready to engage in sexual activities (UNAIDS, 2012).

Respiratory Disease
Smoking, which will be covered in Chapter 5, causes
holes to form in the lungs, leading to a reduction in
the amount of oxygen and carbon dioxide that gets
exchanged. It also destroys small airways that are
used when exhaling, thereby obstructing the lungs
from completely emptying and resulting in short-
ness of breath. This irreversible condition is called
emphysema, which is the most common form of
chronic obstructive pulmonary disease (COPD). A
percentage of emphysema is caused by air pollu-
tion, including secondhand smoke, but about 85%
of cases are due to smoking. However, only 74% of
smokers and 65% of all adults have even heard of
COPD (NIH, 2012).

At first, symptoms of COPD only occur upon physical
exertion. But it gradually becomes harder and harder
to breathe as more tissues become obstructed. Treat-

ments are available that temporarily alleviate the severity of breathing problems, but the disease
remains degenerative. In later stages as less and less oxygen is carried into the blood, people with
COPD can become light-headed and disoriented with just a small amount of physical exertion.
Oxygen therapy may assist in some cases, but even pure oxygen cannot repair deteriorating mem-
branes that simply cannot carry the oxygen into the bloodstream. In advanced stages, people with
COPD eventually lose the ability to breathe altogether. Primarily because of smoking, COPD is the
fourth leading cause of death worldwide, and recently moved ahead of stroke to become the third
leading cause of death in the United States (NIH, 2012; WHO, 2011).

Osteoporosis

If you look at human bones under a microscope, you will see that that they are full of holes. In-
stead of having a smooth texture, they look more like a honeycomb (see Figure 4.4). This means

Stockbyte/Thinkstock

The most common form of COPD is caused
by smoking tobacco.

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CHAPTER 4Section 4.5 Disease in Adulthood

that bones get weaker when the “holes” in the structure become larger. Although doctors con-
sider this process of osteoporosis a disease, it is also a part of maturation. Osteoporosis can be so
severe that a simple movement like picking up a box or even coughing can cause a bone fracture.
The loss of bone accelerates the compression of the spinal column, and individuals often develop
a hunchback as the spine bends forward. Osteoporosis is the primary reason that hip fractures
among the elderly occur so often.

Figure 4.4: A look at
osteoporosis

Osteoporosis results in less dense,
more porous bones (image on
right) as compared to healthy
bones (image on left).

Source: JACOPIN/BSIP/SuperStock

Beginning in early adulthood, women lose about 1% of bone mass, and men lose about .5% each
year. Research is not conclusive about the relative effects of genetics and lifestyle with regard to
risk factors, but we do know that certain choices can accelerate the loss of bone tissue. Smoking,
lack of calcium in the diet, and heavy alcohol use are all risk factors for osteoporosis. Women are
twice as likely to have osteoporosis as men. Among women it is the leading cause of broken bones
(Jett, 2011b). In the United States and worldwide, there are large racial and ethnic differences in
osteoporotic bone fractures, but some demographic trends have changed (Kanis et al., 2002). For
instance, hip fractures among White women in the United States have declined recently, while
those among minority women have increased (Brauer, Coca-Perraillon, Cutler, & Rosen, 2009;
Zingmond, Melton, & Silverman, 2004).

Using Psychology to Inform Learning: Osteoporosis

Students often ask how the negative effects of low socioeconomic status (SES) can be reversed.
Osteoporosis presents a clear example. On average, people who are wealthier and better edu-
cated have a lower incidence of osteoporosis and its precursor, osteopenia. Lack of money and
educational degrees (the chief components of SES) are associated with osteoporosis, but they do
not directly cause it—rather, the behaviors we associate with a higher income and more educa-
tion reduce the incidence of these diseases.

(continued)

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CHAPTER 4Section 4.5 Disease in Adulthood

Using Psychology to Inform Learning: Osteoporosis (continued)

Whenever individuals at higher risk for osteoporosis become better informed, they can engage in
behaviors that mimic lower-risk individuals. Though it may be more difficult for lower-income indi-
viduals who lack transportation and other resources, there is generally nothing to restrict people
from exercising, not smoking, making healthier food choices, and maintaining a normal weight.

Osteoporosis receives little of the attention directed to breast cancer and other diseases, yet it
has been called a “leading cause of debility and declining quality of life [for older] women world-
wide” (Harris, Nealy, Jackson, & Thornton, 2012, p. 310). Beginning at a young age and continuing
into old age, there are interventions that you can begin now regardless of your SES, like making
sure you are consuming enough calcium and producing or consuming enough vitamin D, which
the body uses to absorb calcium.

Osteoporosis carries serious risks of long-term
disability and death due to complications of
fractures. Each year more U.S. women experi-
ence osteoporotic bone fractures than the com-
bined incidence of death due to heart disease
and breast cancer (Cauley, 2011). Yet, in a study
of over 200,000 women aged 50 and older,
nearly half were not aware that they had low
bone mineral density, including 7% who were
diagnosed with osteoporosis (Siris et al., 2001).

The best way to prevent osteoporosis is to
invest in your bones at a young age. Bone mass
does not peak until about 30 years of age, so
exercising and obtaining enough calcium while
tissue is still being formed is essential for opti-
mal bone health. In addition, younger people
in general benefit from resistance training, or
weight-bearing exercises, which can include
running, walking, and dancing in addition to
lifting weights. Biking, swimming, and many non-weight-bearing exercise machines provide good
cardiovascular conditioning, but are not particularly helpful in promoting bone health. Though for
many years experts thought that weight training had a negative effect on young bodies, a compre-
hensive review found that most injuries from those activities are accidental (e.g., pinching, drop-
ping weights) rather than skeletal. Although once thought to be a high-risk activity for youth and
younger athletes, with qualified instructors and proper supervision, it appears to be as safe as any
other sports or recreational activity (Faigenbaum & Myer, 2010).

Burger/Phanie/SuperStock

Beginning in middle adulthood, women are at a
higher risk of developing osteoporisis than men.

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CHAPTER 4Section 4.5 Disease in Adulthood

Skin Cancer
Skin cancer is another disease that becomes more common with age. Exposure to the sun without
protection and the use of tanning salons magnifies the risk for skin cancer, which is the most com-
mon form of cancer overall (Doré & Chignol, 2012; Rogers et al., 2010). Milder types of skin cancer
include squamous cell and basal cell. These forms often start out as reddish patches or feel like
scabs that do not heal. Treatment usually takes only a few moments in a dermatologist’s office.
With proper intervention, they pose little risk to long-term health.

Using Psychology to Inform Learning: Healthy Living

Imagine you need to buy a specific textbook for class and a computer on the same day. They are
both available within a few miles of you, but 20 miles away in opposite directions. They are both
on sale, and you only have time to go one direction. If you drive north, you can save 10% on the
computer that will otherwise cost you $700. Twenty miles to the south, a used copy of the text
(the only one around) is selling for $8. If you do not buy it today, it will run you $65 to purchase
a new copy. Stop reading and decide which direction you will drive. Most people will choose to
drive the extra distance in order to snag the deal on the text. But in this scenario, you are clearly
better off saving money on the computer. The base price of the item is irrelevant; it is only impor-
tant how much you are potentially saving by going the extra distance.

Similarly, in order to remain healthy, people often engage in complicated routines that provide lit-
tle benefit while overlooking easy interventions. Many people drink only bottled water but think
nothing of routinely baking in the sun without sunscreen. Drinking city water is usually regulated
and healthy, whereas repeated sun exposure can literally be fatal. Sunscreen is inexpensive and
provides an easy preventive treatment. If you are concerned about your history of sun exposure,
be sure to ask your doctor or visit a dermatologist if you have specific concerns.

In the United States, about 5% of new cases of cancer each year are the most dangerous type of
skin cancer, melanoma, accounting for over 12,000 yearly deaths (ACS, 2012). Melanomas may
first appear to be benign moles or spots on the skin, and, as with many forms of cancer, early
detection is key to its prevention. If you remember the ABCDE rule, the chance of complete recov-
ery from skin cancer is excellent. See Figure 4.5 for examples of common moles and melanoma
moles on the A–D spectrum.

A is for Asymmetry: A skin cancer spot is usually not symmetric.

B is for Border: A spot with unclear edges should be examined.

C is for Color: A spot with more than one color is suspicious.

D is for Diameter: A spot that is larger than a pencil eraser should be examined.

E is for Elevation: The spot is not smooth but is uneven or bumpy.

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CHAPTER 4Section 4.5 Disease in Adulthood

Figure 4.5: Common moles versus melanoma

Melanoma examples. Identify the ABCDE components.

Source: From Skin Cancer Foundation, National Cancer Institute. Retrieved from http://visualsonline.cancer.gov/

Common Moles Melanoma Moles

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http://visualsonline.cancer.gov/

CHAPTER 4Section 4.5 Disease in Adulthood

The incidence of melanoma has been increasing over the last 30 years, but the number of people
who die from it has dropped, especially among those younger than 50. New diagnoses among
Whites are ten times greater than among Blacks. However, late stage melanomas are significantly
more common among Blacks and Hispanics than among Whites. So while melanoma is much less
common among those with darker skin tones, it is much more frequently fatal. (Hu, Soza-Vento,
Parker, & Kirsner, 2006). These consequences are probably due to an assumption of low risk in
these groups, resulting in a lack of knowledge or pursuit of medical intervention. Importantly, if
skin cancer remains localized, the chances of long-term survival (5 years and more) is 98%; if lack
of detection or treatment has allowed the cancer to spread, survival rates drop to 15% (ACS, 2012).

Applying makeup that contains ultraviolet protection or a daily sunscreen with a sun protection
factor (SPF) of 30 or higher is a fairly painless way to substantially reduce exposure to the harm-
ful rays of the sun. Wearing a hat and sunglasses when you know you will be in the sun all day is
an easy precaution as well. Water and snow reflect more rays, so people need to be extra careful
around beaches, lakes, and mountains.

Diseases of the Cardiovascular System
Though adults are often most afraid of cancer, more men and women die of diseases of the car-
diovascular system (the heart and its arteries) than any other cause (CDC, 2013). When arteries
thicken, harden, and become clogged, blood flow becomes restricted. Consequently, organs and
tissues receive less oxygen and are more likely to fail. When blood and oxygen is not able to ade-
quately supply the heart or brain, this results in a heart attack or stroke. Overall, vascular diseases
are responsible for roughly 31% of all U.S. deaths, more than all forms of cancer combined. A
person’s risk of dying from heart disease is 25 times greater in later middle age than in early adult-
hood. Risks rise with added pounds, so as BMI increases, so does risk of cardiovascular disease.

Preventing stroke is strikingly similar to preventing other major diseases. Guidelines include man-
aging hypertension (high blood pressure), reducing fat and salt intake, refraining from smoking,
controlling diabetes, maintaining a healthy weight, exercising regularly, drinking alcohol only in
moderation, and avoiding the use of illicit drugs. Perhaps the most important variable that directly
affects cardio- and cerebrovascular health is the level of cholesterol that builds up in the blood.
Cholesterol is a fatlike substance that is involved in a number of physiological functions, includ-
ing the manufacture of cell walls. There are two types of cholesterol: “bad” cholesterol consists
of low-density lipoproteins (LDL), and “good” cholesterol is made up of high-density lipoproteins
(HDL). LDL (“bad” cholesterol) comes from high-fat foods like burgers, chips, and high-fat ice
cream. As it travels through the bloodstream, it clings to arteries and restricts blood flow. HDL
(“good” cholesterol”) is a different kind of fat. It comes from nuts, seeds, avocados, and olive,
coconut, and other vegetable oils. High levels of HDL carry excess cholesterol to the liver where it
is removed from the body.

Eating a diet low in hydrogenated fats and saturated fats (usually listed on food labels) and exer-
cising regularly are the best ways to prevent cardiovascular diseases, though genetics plays a
large role in the inheritance of cholesterol levels. Statin drugs like Lipitor are effective in lowering
cholesterol, regardless of whether levels are high due to diet or genetics. The American Heart
Association recommends maintaining an overall serum cholesterol number below 200, but many
cardiologists recommend even lower goals. Once again, maintaining a healthy diet and avoiding
sedentary activities are most effective in promoting cardiovascular health.

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CHAPTER 4Section

4.6 Degenerative Diseases of the Brain

A mental health issue that occurs primarily in aging adults is dementia, a broad term that refers to an abnormal rate of deterioration in mental functioning. Neurons (brain cells) deteriorate or no longer function properly. These physical changes in the brain cause dis-
turbances in memory, behavior, and ability to think clearly. Researchers believe the first signs of
dementia include forgetting common directions while driving, forgetting more names than usual,
or misplacing items more so than in the past. However, numerous studies have found a significant
association between physical performance and dementia, even among those over 90 years old.
Before cognitive declines even begin, demetia can be predicted by physical tests like grip strength
(Bullain et al., 2013; Wang, Larson, Bowen, & van Belle, 2006). Others, however, believe that more
studies are needed before we can make definitive conclusions (Cooper et al., 2011).

Demetia is progressive. Though not always
noticeable to others in its early stages, it
soon becomes problematic. During the mid-
dle stages of dementia, lack of self-care and
hygiene become noticeable. Memory loss
becomes more dramatic, and there is diffi-
culty communicating, planning, and organiz-
ing. Those with moderate dementia may fre-
quently become frustrated and agitated, often
due to confusion about the changes they are
experiencing. Throughout these stages it is
important to continue to talk to the person
experiencing dementia about what is happen-
ing and continue to particiate in regular activi-
ties—often with increased supervision. And
regardless of the type of dementia, remaining
physically active slows its progression (Scar-
meas et al., 2011; Verdelho et al., 2012).

Cognitive exercises appear to slow dementia
and specifically preserve skills. Adults who par-
ticipate in activities that stimulate the brain,
like reading, playing board games, doing cross-

word puzzles, and participating in discussions are less likely to experience dementia 5 years later.
Other studies have found that an active mind, an active social network, and good emotional sup-
port can also stave off dementia (Holtzman et al., 2004; Seidler et al., 2004) . As the population
continues to age, many have suggested routine screening for dementia (including the National
Health Service of the United Kingdom.) However, there is little consensus on the benefits of doing
so (e.g., Brunet et al., 2013; Koekkoek, Janssen, Kappelle, Biessels, & Rutten, 2013).

Alzheimer’s Disease
The most well-known and common form of dementia is Alzheimer’s disease. Its symptoms are
similar to other forms of dementia. There are an estimated 5.4 million people living with Alzheim-
er’s in the United States; it is the sixth leading cause of death in the United States among those

Ron Mossler

The physical signs of deterioration are evident
in this photo of two men who are both 87 years
old. It is apparent that one is relatively healthy
and vibrant whereas the other (the author’s
father) exhibits the distant, vacant look that is
characteristic of dementia.

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CHAPTER 4Section 4.6 Degenerative Diseases of the Brain

65 years of age and older, and accounts for medical costs of $200 billion per year (AA, 2012; CDC,
2013). Worldwide costs for the treatment and care of Alzheimer’s and related dementia exceed
$600 billion (Batsch & Mittelman, 2012).

Figure 4.6: Brain changes resulting from
Alzheimer’s disease

Alzheimer’s disease causes cells to die and brain tissues to
shrink. Consequently, body functions deteriorate.

Experts do not understand the etiology of Alzheimer’s, but it is likely that it develops as a function
of multiple causes. Like other forms of dementia, healthy brain tissue deteriorates, taking with
it the network of knowledge and memories. There are two hallmarks that identify Alzheimer’s.
Amyloid plaques are deposits that clump inside of blood vessels. These clumps may even spread,
destroying more brain tissue. There are also twisted fibers, called neurofibrillary tangles, which
build up inside of neurons. The tangles interfere with the ability of cells to communicate and may
cause healthy neurons to die. See Figure 4.6 for a comparison of a healthy brain and one affected
by advanced Alzheimer’s disease.

There is no known cure for Alzheimer’s disease, though drugs can sometimes reduce symptoms,
including the behavioral changes that impact caregivers and family. Doctors most commonly
prescribe medications to improve concentration and slow the progression of memory loss and
confusion, but they only work for a limited time. The disease remains progressive and fatal.
There is always hope among alternative treatments, but none have yet passed the standards of
scientific study. As noted, the best prevention and treatment efforts include remaining mentally
and physically active.

Parkinson’s Disease
After Alzheimer’s, Parkinson’s disease is the second most common neurodegenerative disease
and is caused by the degeneration of neurons that produce dopamine in the brain. Initial symp-
toms include tremors and shaking, stiff joints, slowed movement, and problems with balance
and posture. It usually progresses to difficulty in speaking and expression, diminished smiling and
blinking, and cognitive deficits (Massano & Bhatia, 2012). About 30% of Parkinson’s sufferers also
have dementia—roughly six times more than those without Parkinson’s. It is an incurable disease,
but some symptoms can be treated. Doctors have recently begun to successfully treat advanced
patients with deep brain stimulation (Williams et al., 2010). In this process, surgeons implant elec-
trodes into parts of the brain that are responsible for the tremors. Electrical pulses are then sent
through the electrodes in order to block the nerve impulses. Two of the best-known sufferers of
Parkinson’s disease are former heavyweight-boxing champion Muhammad Ali and popular actor
Michael J. Fox.

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CHAPTER 4Summary of Major Concepts

Chapter Summary

Wrapping Up and Moving Ahead
Changes in physical functioning are closely connected to psychological aspects of development,
including factors related to secondary aging. Beyond physical functioning, senses, visible changes,
and sexuality all impact how people feel about themselves. Education about various diseases and
preventive measures has a great impact on aging outcomes, often with little cost in money or
time. Simple interventions like glaucoma screening and taking calcium supplements can have a
tremendous effect on well-being. Other conditions are substantially impacted by lifestyle, espe-
cially related to diet and exercise. The next chapter will concentrate more fully on these secondary
variables and also focus on additional activities that facilitate successful aging.

Summary of Major Concepts
• There are a number of theories that propose reasons why humans live as long as they do

and what causes a person’s ultimate death.
• Programmed theories suggest that there are built-in limits to how long humans can live.

Genes are programmed to initiate age-related changes, which eventually lead to more
susceptibility to disease.

• Damage theories view the body like mechanical devices. As the human machine ages, its
component parts wear out. The current recommendations to eat foods rich in antioxi-
dants grew out of damage theory.

• In addition to chronological milestones, many people look at visible changes as indica-
tive of the aging process. Underneath the outward signs are corresponding changes in
skin, muscle, bone, and other systems.

• Hormones govern much of our reproductive facility and sexual behavior. There are defin-
itive consequences for advancing age in a woman’s ability to conceive and carry a child
to term. For men, there is increasing evidence that age is a determining factor in birth
outcomes as well. The vast majority of both men and women remain vital and interested
in sex well into late adulthood.

• Income and education are two key factors influencing our health and development. Edu-
cation has a strong relationship to income, which has a direct influence on health and
availability of healthcare resources.

• About 80% of sexually transmitted infections occur in those 25 years of age and younger.
However, increasing numbers of older adults are contracting STIs as preventive efforts
normally focus elsewhere.

Think and Review:

What is the primary visible difference between Alzheimer’s disease and Parkinson’s disease–
related dementia?

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CHAPTER 4

Key Terms

• Most individuals are unaware that chronic lung diseases are one of the leading causes of
death in the United States and worldwide. Smoking is by far its strongest risk factor.

• Diseases like osteoporosis and skin cancer are partly biological and partly due to life-
style. The effects of these diseases can be moderated by specific interventions.

• Cardiovascular diseases kill more people in the United States and worldwide than any
other cause. Lifestyle choices, including diet and exercise, and medications are impor-
tant instruments in reversing its effects.

• Dementia is an especially debilitating illness that firmly blurs the boundary between
physical, cognitive, and psychosocial development. Due to our aging population, its eco-
nomic and social impact continues to grow.

Key Terms

acquired immune deficiency syndrome
(AIDS) Refers to the symptoms of the disease
that occurs due to HIV infection.

Alzheimer’s disease Most common form
of progressive brain disease resulting in
dementia.

amyloid plaques Deposits in the brains of
Alzheimer’s patients that clump inside of blood
vessels.

cataract Clouding of the lens of the eye; the
leading cause of blindness worldwide.

cholesterol Fatlike substance that is manufac-
tured in cells and can build up in blood due to
the intake of some high-fat foods.

chronic obstructive pulmonary disease
(COPD) Global term that refers to a number
of lung diseases, the most common of which is
emphysema.

damage theories of aging A group of theo-
ries that suggest there is an accumulation of
cellular or other physical damage that limits
longevity.

dementia A broad term that refers to an
abnormal rate of deterioration in mental func-
tioning. Includes dementia related to Alzheim-
er’s disease and Parkinson’s disease.

emphysema A kind of lung disease that results
in shortness of breath, usually due to smoking.

erectile dysfunction Inability of males to
achieve and maintain an erection.

fertility The capacity to reproduce.

free radicals Electrically charged chemicals that
build up as a normal part of cell production.

glaucoma Increased pressure on the eyeball
leading to damage of the optic nerve. Associ-
ated with eye injury or trauma.

hormone replacement therapy (HRT)
Normally, an intervention that includes
estrogen and progestin to treat symptoms
and outcomes related to perimenopause.

human immunodeficiency virus (HIV) The
virus that causes AIDS.

human papillomavirus (HPV) A virus that can
cause genital warts and cervical cancer.

hypertension High blood pressure.

life expectancy Average age of death for a
specific population.

longevity Theoretical maximum number of
years any one person is expected to live.

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CHAPTER 4Key Terms

macular degeneration Disease of the eye
that is the leading cause of blindness in the
United States.

menopause One year after the end of a
woman’s last menstrual period.

mortality rate Number of deaths in a
population.

neurofibrillary tangles Twisted fibers in the
brains of Alzheimer’s patients, which build up
inside of neurons.

osteopenia The precursor to osteoporosis;
refers to lowered bone density that is not as
severe as osteoporosis.

osteoporosis Disease of the bones that causes
them to lose density and become more sus-
ceptible to fracture.

Parkinson’s disease Second most common
neurodegenerative disease that results in
dementia.

perimenopause The period of hormonal
changes during which women undergo a
transition to cease menstruation and become
unable to conceive children.

presbyopia Loss of near vision.

primary aging Aging due to biology or
maturation.

programmed theories of aging A group of
theories that suggest there are biological and
genetic limits on how long humans can live.

prostate gland A small gland under the bladder
of men; often becomes enlarged in older men.

sarcopenia Gradual loss of muscle mass and
strength that begins in the thirties.

secondary aging Aging due to lifestyle or envi-
ronmental circumstances.

sexually transmitted diseases Diseases that
occur as a result of infections that were con-
tracted through sexual contact.

statin drugs Group of drugs that are effective
in lowering cholesterol in the blood.

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mos85767_04_c04_083-108.indd 108 6/21/13 10:01 AM

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