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1.1
THIN K IN G A BO UT
DEV E L O P M E N T
Recurring Issues in Human Development
Basic Forces in Human Development: The
Biopsychosocial Framework
❚ REAL PEOPLE: APPLYING HUMAN
DEVELOPMENT:
Sarah and Elizabeth Delany
1.2
DEV E L O P M E N TA L T HE O R IES
Psychodynamic Theory
Learning Theory
Cognitive-Developmental Theory
The Ecological and Systems Approach
Life-Span Perspective, Selective
Optimization With Compensation, and
Life-Course Perspective
The Big Picture
1.3
DOIN G D E V E L O P M E N TA L
RES E A RC H
Measurement in Human Development
Research
General Designs for Research
Designs for Studying Development
❚ SPOTLIGHT ON RESEARCH:
Stability and Change in Life Satisfaction
Integrating Findings From Different Studies
Conducting Research Ethically
Communicating Research Results
Applying Research Results: Social Policy
❚ CURRENT CONTROVERSIES:
Stem Cell Research
S U M M A RY
KEY T E RM S
L E A RN M O R E A BO UT IT
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C H A P T E R
1
The Study of
Human Development
© Masterfile
D id you ever wonder how you managed to go from being a young child to the more experienced
person you are now? Or what might lie ahead in your future over the next few years or decades?
Take a moment and think about your life to this point. Make a note to yourself about—or share with
someone else—your fondest memories from childhood or the events and people who have most
influenced you.
Thinking about your past experiences is the beginning of an exciting personal journey. Think
about major moments or experiences you’ve had. What happened? Why do you think things happened the way they did? What major forces shaped that event, and have shaped your life?
In this course, you will have the opportunity to ask some of life’s most basic questions: How did
your life begin? How did you go from a single cell—about the size of the period at the end of a sentence in this text—to the fully grown, complex adult person you are today? Will you be the same or
different by the time you reach late life? How do you influence other people’s lives? How do they influence yours? How do the various roles you have throughout life—child, teenager, partner, spouse, parent,
worker, grandparent—shape your development? How do we deal with our own and others’ deaths?
These are examples of the questions that create the scientific foundation of human development, the multidisciplinary study of how people change and how they remain the same over time.
Answering these questions requires us to draw on theories and research in the physical and social
sciences, including biology, genetics, chemistry, medicine, psychology, sociology, demography, ethnography, economics, and anthropology. The science of human development reflects the complexity and
uniqueness of each person and each person’s experiences as well as commonalities and patterns
across people. As a science, human development is firmly grounded in theory and research as it seeks
to understand human behavior.
Before our journey begins, we need to collect some things to make the trip more rewarding. In
this chapter, we pick up the necessary road maps that point us in the proper direction: a framework
to organize theories and research, common issues and influences on development, and the methods
developmentalists use to make discoveries. Throughout the book, we will point out how the various
theories and research connect to your own experience. Pack well, and bon voyage.
3
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1.1 THINKING ABOUT DEVELOPMENT
L E A R N I N G OB J E C T I V E S
❚ What fundamental issues of development have scholars
addressed throughout history?
❚ What are the basic forces in the biopsychosocial framework?
How does the timing of these forces affect their impact?
J
avier Suarez smiled broadly as he held his newborn grandson for the first time. So many
thoughts rushed into his mind—What would Ricardo experience growing up? Would the
poor neighborhood they live in prevent him from reaching his potential? Would the family
genes for good health be passed on? How would Ricardo’s life growing up as a Latino in the
United States be different from Javier’s own experiences in Mexico?
LIKE MANY GRANDPARENTS, Javier wonders what the future holds for his grandson. The
human development
the multidisciplinary study of how people
change and how they remain the same
over time
questions he asks are interesting in their own right, but they are important for another reason: They bear on general issues of human development that have intrigued
philosophers and scientists for centuries. In the next few pages we introduce some of
these issues, which surface when any aspect of development is being investigated.
| Recurring Issues in Human Development
In thinking about your life to this point, you may have considered the factors that
have influenced the lives of yourself and others. These factors probably included such
things as your genetic heritage, your family or neighborhood, the observation that
some changes in your life are sudden whereas others are more gradual, and that some
people seem to be strongly influenced by their culture whereas others are not.
Your speculations capture three fundamental issues that pervade modern research
on human development: nature versus nurture, continuity versus discontinuity, and
universal versus context-specific development. The “versus” suggests that each issue
is an “either–or,” but they are actually continua. That is, human development at the
level of individual people is a blend to differing degrees of each concept in the pair
that describe each issue. Because these issues underlie all the topics in this book, let’s
examine each one.
Nature Versus Nurture
nature–nurture issue
the degree to which genetic or hereditary
influences (nature) and experiential or
environmental influences (nurture) determine the kind of person you are
T H INK ABO UT I T
Think of some common, everyday
behaviors, such as dancing or playing
basketball with your friends. How do
nature and nurture influence these
behaviors?
Think for a minute about a particular characteristic that you and several people in your
family have, such as intelligence, good looks, or a friendly and outgoing personality.
Why is this trait so prevalent? Is it because you inherited the trait from your
parents? Or is it because of where and how you and your parents were brought up?
Answers to these questions illustrate different positions on the nature–nurture issue,
which involves the degree to which genetic or hereditary influences (nature) and experiential or environmental influences (nurture) determine the kind of person you are.
Scientists once hoped to answer these questions by identifying either heredity or environment as the cause of a particular aspect of development. The goal was to be able
to say, for example, that intelligence was due to heredity or that personality was due
to experience. Today, however, we know that virtually no feature of life-span development is due exclusively to either heredity or environment. Instead, development is
always shaped by both: Nature and nurture are mutually interactive influences.
For example, in Chapter 2 you will see that some individuals inherit a disease that
leads to mental retardation if they eat dairy products. However, if their environment
contains no dairy products, they develop normal intelligence. Similarly, in Chapter 10
you will learn that one risk factor for cardiovascular disease is heredity but that lifestyle factors such as diet and smoking play important roles in determining who has
heart attacks.
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As these examples illustrate, a major aim of human development research is to
understand how heredity and environment jointly determine development. For Javier,
it means his grandson’s development will surely be shaped both by the genes he inherited and by the experiences he will have.
Continuity Versus Discontinuity
Think of some ways in which you remain similar to how you were as a 5-year-old.
Maybe you were outgoing and friendly at that age and remain outgoing and friendly
today. Examples like these suggest a great deal of continuity in development. Once a
person begins down a particular developmental path—for example, toward friendliness or intelligence—he or she stays on that path throughout life. According to this
view, if Ricardo is a friendly and smart 5-year-old then he should be friendly and smart
as a 25- and 75-year-old.
The other view—that development is not always continuous—is illustrated in the
Hi and Lois cartoon. Sweet and cooperative Trixie has become assertive and demanding. In this view, people can change from one developmental path to another and perhaps several times in their lives. Consequently, Ricardo might be smart and friendly at
age 5, smart but obnoxious at 25, and wise but aloof at 75!
The continuity–discontinuity issue concerns whether a particular developmental
phenomenon represents a smooth progression throughout the life span (continuity) or a
series of abrupt shifts (discontinuity). Of course, on a day-to-day basis, behaviors often
look nearly identical, or continuous. But when viewed over the course of many months
or years, the same behaviors may have changed dramatically, reflecting discontinuous
change. Throughout this book, you will find examples of developmental changes that
appear to be more like continuities and others that appear to be more like discontinuities. For example, in Chapter 5 you will see evidence of continuity: Infants who have
satisfying emotional relationships with their parents typically become children with
satisfying peer relationships. But in Chapter 15 you will see an instance of discontinuity: After spending most of adulthood trying to ensure the success of the next generation and to leave a legacy, older adults turn to evaluating their own lives in search of
closure and a sense that what they have done has been worthwhile.
continuity–discontinuity issue
whether a particular developmental
phenomenon represents a smooth progression throughout the life span (continuity)
or a series of abrupt shifts (discontinuity)
Universal Versus Context-Specific Development
universal versus context-specific
development issue
whether there is just one path of development or several paths
Reprinted with special permission of King Features Syndicate.
In some cities in Brazil, 10- to 12-year-olds sell fruit and candy to pedestrians and
passengers on buses. Although they have little formal education and often cannot
identify the numbers on the money, they handle money proficiently (Saxe, 1988). In
contrast, 10- to 12-year-olds in the United States are formally taught at home or school
to identify numbers and to perform the kinds of arithmetic needed to handle money.
Can one theory explain development in both groups of children? The universal versus
context-specific development issue concerns whether there is just one path of development or several. Some theorists argue that, despite what look like differences in development, there is really only one fundamental developmental process for everyone.
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Mathias Oppersdorff / Photo Researchers, Inc.
According to this view, differences in development are simply variations on a fundamental developmental process in much the same way
that cars as different as a Chevrolet, a Honda, and a Porsche are all
products of fundamentally the same manufacturing process.
The opposing view is that differences among people are not simply variations on a theme. Advocates of this view argue that human
development is inextricably intertwined with the context within
which it occurs. A person’s development is a product of complex interaction with the environment, and that interaction is not fundamentally the same in all environments. Each environment has its own set
of unique procedures that shape development, just as the “recipes”
for different cars yield vehicles as different as a Mini Cooper and a
Hummer.
As is the case for the other two issues, individual development reflects both universal and context-specific influences. For example, the
basic order of development of physical skills in infancy is essentially
the same in all cultures. But how those skills are focused or encouraged in daily life may differ across cultures.
Putting all three issues together and using personality to illustrate,
we can ask how heredity and environment interact to influence the
development of personality, whether the development of personality
is continuous or discontinuous, and whether personality develops in
much the same way around the world. To answer these kinds of questions, we need to look at the forces that combine to shape human
development.
Even with little formal education, this Brazilian boy has well-developed mathematical skills,
an example of cultural contextual forces on
development.
Basic Forces in Human Development:
The Biopsychosocial Framework
When trying to explain why people develop as they do, scientists usually consider four
interactive forces:
■
■
■
■
biopsychosocial framework
a useful way to organize the biological,
psychological, and sociocultural forces on
human development
Biological forces include all genetic and health-related factors that affect
development.
Psychological forces include all internal perceptual, cognitive, emotional, and
personality factors that affect development.
Sociocultural forces include interpersonal, societal, cultural, and ethnic factors
that affect development.
Life-cycle forces reflect differences in how the same event affects people of
different ages.
Each person is a product of a unique combination of these forces. No two individuals,
even in the same family, experience these forces in the same way; even identical twins
eventually have different friendship networks, partners, and occupations.
To see why each of these forces is important, think about whether a mother decides to breast-feed her infant. Her decision will be based on biological variables (e.g.,
the quality and amount of milk she produces), her attitudes about the virtues of breastfeeding, the influences of other people (e.g., the father), and her cultural traditions
about appropriate ways to feed infants. Additionally, her decision will reflect her age
and stage of life. Only by focusing on all of these forces can we have a complete view
of the mother’s decision.
One useful way to organize the biological, psychological, and sociocultural forces
on human development is with the biopsychosocial framework. As you can see in
❚ Figure 1.1, the biopsychosocial framework emphasizes that each of the forces interacts with the others to make up development. Let’s look at the different elements of
the biopsychosocial model in more detail.
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❚ Figure 1.1
The biopsychosocial framework shows that
human development results from interacting
forces.
Biological forces
Sociocultural forces
Lifecycle
forces
Psychological forces
Biological Forces
Prenatal development, brain maturation, puberty, menopause,
facial wrinkling, and change in cardiovascular functioning may
occur to you as examples of biological forces. Indeed, major aspects of each are determined by our genetic code. For example,
many children resemble their parents, which shows biological
influences on development. But biological forces also include
the effects of lifestyle factors, such as diet and exercise. Collectively, biological forces can be viewed as providing the raw material necessary and as setting the boundary conditions (in the
case of genetics) for development.
Psychological forces probably seem familiar because they are
the ones used most often to describe the characteristics of a
person. For example, think about how you describe yourself to
others. Most of us say that we have a nice personality and are intelligent, honest, self-confident, or something similar. Concepts
like these reflect psychological forces.
In general, psychological forces are all the internal cognitive, emotional, personality, perceptual, and related factors that influence behavior. Psychological forces have
received the most attention of the three main developmental forces. Much of what
we discuss throughout this text reflects psychological forces. For example, we will
see how the development of intelligence enables individuals to experience and think
about their world in different ways. We’ll also see how the emergence of self-esteem
is related to the beliefs people have about their abilities, which in turn influence what
they do.
© David Young-Wolff / PhotoEdit
Psychological Forces
Biological influences on development help
explain why relatives tend to look alike.
Sociocultural Forces
People develop in the world, not in a vacuum. To understand human development, we
need to know how people and their environments interact and relate to each other.
That is, we need to view an individual’s development as part of a much larger system
in which no individual part can act without influencing all other aspects of the system.
This larger system includes one’s parents, children, and siblings as well as important individuals outside the family, such as friends, teachers, and co-workers. The system also
includes institutions that influence development, such as schools, television, and the
workplace. At a broader level, the society in which a person grows up plays a key role.
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The cultural experiences of this Asian child and
Asian woman will differ from those of people
growing up in different parts of the world.
All of these people and institutions fit together to form a
person’s culture: the knowledge, attitudes, and behavior associated with a group of people. Culture can be linked to a particular country or people (e.g., French culture), to a specific
point in time (e.g., popular culture of the 2000s), or to groups
of individuals who maintain specific, identifiable cultural traditions (e.g., African Americans). Knowing the culture from
which a person comes provides some general information
about important influences that become manifest throughout the life span.
Understanding the impact of culture is particularly important in the United States, the most diverse country in the
world. Hundreds of different languages are spoken, and in
many states no racial or ethnic group constitutes a majority.
The many customs that people bring offer insights into the
broad spectrum of human experience and attest to the diversity of the U.S. population.
Although the U.S. population is changing rapidly, much of the research we describe in this text was conducted on middle-class European Americans. Accordingly,
we must be careful not to assume that findings from this group necessarily apply to
people in other groups. Indeed, there is a great need for research on different cultural
groups. Perhaps, as a result of taking this course, you will help fill this need by becoming a developmental researcher yourself.
Another practical problem that we face is how to describe each group. Terminology changes over time. For example, the terms colored people, Negroes, black Americans, and African Americans have all been used to describe Americans of African
ancestry. In this book, we use the term African American because it emphasizes the
unique cultural heritage of that group of people. Following the same line of reasoning, we use European American (instead of Caucasian or white), Native American
(instead of Indian or American Indian), Asian American, and Latino American.
These labels are not perfect. In some cases, they blur distinctions among ethnic
groups. For example, people from both Guatemala and Mexico may be described as
Latinos. However, their cultural backgrounds vary on several important dimensions,
so we should not view them as being from a homogeneous group. Similarly, the term
Asian American blurs variations among people whose heritage is, for example, Japanese, Chinese, or Korean. Whenever researchers have identified the subgroups in
their research sample, we will use the more specific terms in describing results. When
we use the more general terms, remember that conclusions may not apply to all subgroups within the group described by the more general term.
© Topham / The Image Works
The Forces Interact
Due to life cycle forces, experiencing pregnancy in high school is different from experiencing it later in adulthood.
So far, we’ve described biological, psychological, and sociocultural forces in the biopsychosocial framework as
if they were independent. But as we pointed out earlier
in introducing the notion of the biopsychosocial framework, each force shapes the others.
Consider eating habits. When the authors of this
text were growing up, a “red meat and potatoes” diet was
common and was thought to be healthy. Scientists later
discovered that high-fat diets may lead to cardiovascular
disease and some forms of cancer. Consequently, social
pressures changed what people eat; advertising campaigns were begun; and restaurants began to indicate
which menu items were low in fat. Thus, the biological
forces of fat in the diet were influenced by the social
forces of the times, whether in support of or in opposition to eating beef every evening. Finally, as your authors
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became more educated about diets and their effects
on health, the psychological forces of thinking and
reasoning also influenced their choice of diets. (We
confess, however, that chocolate remains a passion
for one of us!)
This example illustrates that no aspect of human development can be fully understood by examining only one or two of the forces. All three
must be considered in interaction. In fact, we’ll
see later in this chapter that integration across
the three major forces of the biopsychosocial framework is one criterion by which the adequacy of
a developmental theory can be judged. Before we
do that, however, we need to consider one more
aspect of this framework: The point in life at which
a specific combination of biological, psychological,
and sociocultural forces operates matters a great
deal.
Consider the following two situations. Jacqui, a 32year-old woman, has been happily married for 6
years. She and her husband have a steady income.
They decide to start a family, and a month later Jacqui learns she is pregnant. Jenny, a 14-year-old girl,
lives in the same neighborhood as Jacqui. She has
been sexually active for about 6 months but is not
in a stable relationship. After missing her period,
Jenny took a pregnancy test and discovered that
she is pregnant.
Although both Jacqui and Jenny became pregnant, the outcome of each pregnancy will certainly
be affected by factors in each woman’s situation
such as her age, her financial situation, and the extent of her social support systems. The example illustrates life-cycle forces: The same event can have
different effects depending on when it happens
in a person’s life. In the scenarios with Jacqui and
Due to life cycle forces, pregnancy in one’s 30s is experienced differently than pregnancy in
Jenny, the same event—pregnancy—produces hapone’s teens.
piness and eager anticipation for one woman but
anxiety and concern for the other.
The influence of life-cycle forces reflects the influences of biological, psychological, and sociocultural forces at different points in the life span. A particular issue or
event (such as pregnancy) may recur at different points in life, but how a person
deals with it depends on their accumulated experience. For example, trust is an issue that is addressed throughout life (Erikson, 1982). Beginning as an infant’s trust
in parents, it develops into progressively more complex forms of trust over the life
span for friends and/or lovers—as Jacqui can attest and as Jenny will ultimately learn.
Each time a person revisits trust issues, he or she builds on past experiences in light
of intervening development. This accumulated experience means that the person will
deal with trust in a new way and that trust is shown in different ways across the life
span.
Combining the four developmental forces gives a view of human development that
T HIN K ABO U T IT
encompasses the life span yet appreciates the unique aspects of each phase of life. From
Earning a college degree is another
event that has different effects based on
this perspective we can view each life story as a complex interplay among the four
when it happens in a person’s life. Can
forces. One way to see this is to look back on life from the perspective of old age. Sadie
you think of other events like these?
and Bessie Delany, discussed in the Real People feature, are good examples of this.
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Timing Is Everything: Life-Cycle Forces
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Real People: Applying Human Development
Understanding how
the developmental
forces affect people’s
personal developmental paths greatly enhances
our knowledge by helping us understand how
people’s lives unfold. This is especially helpful
when you look back over people’s lives from the
perspective of old age: “When you get real old,
honey,” said Elizabeth (Bessie) Delany, “you lay it
all on the table.”
There’s an old saying: “Only little children and
old folks tell the truth.” With her sister Sarah
(Sadie), Bessie lived through and was shaped by
some of the most important historical events
of the late 19th and 20th centuries. The sisters
grew up during a time when segregation was
the rule in the South, so they experienced many
forms of discrimination as well as the civil rights
and the women’s movements. They were born
more than a decade before the invention of
the airplane, and they lived to see people travel
to space and walk on the moon. Each rose to
professional prominence, Bessie as the second
African American woman to become a licensed
dentist in New York and Sadie as the first African
American to teach domestic science on the highschool level in New York City public schools.
From a biological perspective, they clearly
had good genes for longevity. Psychologically,
they endured the effects of discrimination. Socioculturally, they were pioneers in many ways,
and they were not only shaped by historical
events but helped shape them as well. From a life
cycle perspective, the sisters repeatedly faced
obstacles and challenges to their careers but
always managed to overcome them.
As to the rest of their story, they never married. Bessie died at age 104 in 1995, and Sadie
AP Images
Sarah and Elizabeth Delany
Sadie Delany (attending her sister
Bessie’s funeral) is an example of
how historical events can shape a life.
died at age 109 in 1999. Discover for yourself
how social and historical events affected their
lives by reading their story, which is listed in the
readings at the end of this chapter.
Test Yourself
INTERPRET
How does the biopsychosocial framework provide insight into
the recurring issues of development (nature–nurture, continuity–discontinuity, universal–context-specific)?.
APPLY
How does your life experience reflect the four developmental
forces?
Recall answers: (1) genetics, (2) continuity, (3) Biological
RECALL
1. The nature–nurture issue involves the
degree to which
and the environment influence human
development.
2. Azar remarked that her 14-year-old son is incredibly shy
and has been ever since he was a little baby. This illustrates
the
of development.
3.
forces include genetic and health
factors.
1.2 DEVELOPMENTAL THEORIES
L E A R N I N G OB J E C T I V E S
❚
❚
❚
❚
What is a developmental theory?
How do psychodynamic theories account for development?
What is the focus of learning theories of development?
How do cognitive-developmental theories explain changes in
thinking?
❚ What are the main points in the ecological and systems
approach?
❚ What are the major tenets of life-span and life-course
theories?
M
arcus has just graduated from high school, first in his class. For his proud mother, Betty,
this is a time to reflect on her son’s past and to ponder his future. Marcus has always
been a happy, easy-going child—a joy to rear. And he’s constantly been interested in learning.
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Betty wonders why he is so perpetually good-natured and so curious. If she knew the secret,
she laughed, she could write a best-selling book and be a guest on Oprah!
TO ANSWER BETTY’S QUESTIONS ABOUT HER SON’S GROWTH, developmental researchers
would provide a theory of his development. Theories are essential because they provide the “why’s” for development. What is a theory? In human development, a theory
is an organized set of ideas that is designed to explain development. For example, suppose friends of yours have a baby who cries often. You could imagine several explanations for her crying. Maybe the baby cries because she’s hungry; maybe she cries to
get her parents to hold her; maybe she cries because she’s simply a cranky, unhappy
baby. Each of these explanations is a very simple theory: It tries to explain why the
baby cries so much. Of course, actual theories in human development are much more
complicated, but the purpose is the same—to explain behavior and development.
There are no truly comprehensive theories of human development to guide research (Lerner, 2002). Instead, five general perspectives influence current research:
psychodynamic theory; learning theory; cognitive theory; ecological and systems
theory; and theories involving the life-span perspective, selective optimization with
compensation, and the life-course perspective. Let’s consider each approach briefly.
| Psychodynamic Theory
Psychodynamic theories hold that development is largely determined by how well
people resolve conflicts they face at different ages. This perspective traces its roots to
Sigmund Freud’s theory that personality emerges from conflicts that children experience between what they want to do and what society wants them to do.
Building on Freud’s idea, Erik Erikson (1902–1994) proposed the first comprehensive life-span view, his psychosocial theory, which remains an important theoretical
framework today.
theory
an organized set of ideas that is designed
to explain development
psychodynamic theories
theories proposing that development is
largely determined by how well people
resolve conflicts they face at different ages
psychosocial theory
Erikson’s proposal that personality development is determined by the interaction
of an internal maturational plan and
external societal demands
In his psychosocial theory, Erikson proposed that personality development is determined by the interaction of an internal maturational plan and external societal demands. He proposed that the life cycle is composed of eight stages and that the order
of the stages is biologically fixed (the eight stages shown in ● Table 1.1). You can see
that the name of each stage reflects the challenge people face at a particular age. For
example, the challenge for young adults is to become involved in a loving relationship.
Challenges are met through a combination of inner psychological influences and outer
social influences. When challenges are met successfully, people are well prepared to
meet the challenge of the next stage.
© Bettmann / Corbis
Erikson’s Theory
Erik Erikson
● TABLE 1.1
The Eight Stages of Psychosocial Development in Erikson’s Theory
Psychosocial Stage
Age
Challenge
Basic trust vs. mistrust
Birth to 1 year
To develop a sense that the world is safe, a “good place”
Autonomy vs. shame
and doubt
Initiative vs. guilt
Industry vs. inferiority
Identity vs. identity
confusion
Intimacy vs. isolation
Generativity vs.
stagnation
Integrity vs. despair
1 to 3 years
To realize that one is an independent person who can make decisions
3 to 6 years
6 years to adolescence
Adolescence
To develop the ability to try new things and to handle failure
To learn basic skills and to work with others
To develop a lasting, integrated sense of self
Young adulthood
Middle adulthood
To commit to another in a loving relationship
To contribute to younger people through child rearing, child care, or
other productive work
To view one’s life as satisfactory and worth living
Late life
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© Bettmann / Corbis
The sequence of stages in Erikson’s theory is based on the epigenetic principle,
which means that each psychosocial strength has its own special period of particular
importance. The eight stages represent the order of this ascendancy. Because the stages
extend across the whole life span, it takes a lifetime to acquire all of the psychosocial
strengths. Moreover, Erikson realizes that present and future behavior must have its
roots in the past, because later stages are built on the foundation laid in previous ones.
The psychodynamic perspective emphasizes that the trek to adulthood is difficult
because the path is strewn with challenges. Outcomes of development reflect the manner and ease with which children surmount life’s barriers. When children overcome
early obstacles easily, they are better able to handle the later ones. A psychodynamic
theorist would tell Betty that her son’s cheerful disposition and his academic record
suggest that he has handled life’s early obstacles well, which is a good sign for his
future development.
B. F. Skinner
| Learning Theory
epigenetic principle
in Erikson’s theory, the idea that each
psychosocial strength has its own special
period of particular importance
In contrast to psychodynamic theory, learning theory concentrates on how learning
influences a person’s behavior. This perspective emphasizes the role of experience,
examining whether a person’s behavior is rewarded or punished. This perspective
also emphasizes that people learn from watching others around them. Two influential
theories in this perspective are behaviorism and social learning theory.
Behaviorism
operant conditioning
learning paradigm in which the consequences of a behavior determine whether
a behavior is repeated in the future
reinforcement
a consequence that increases the future
likelihood of the behavior that it follows
punishment
a consequence that decreases the future
likelihood of the behavior that it follows
Early in the 20th century, John Watson (1878–1958) believed that infants’ minds were
essentially “blank slates” and argued that learning determines what people will become. He assumed that, with the correct techniques, anything could be learned by
almost anyone. In Watson’s view, then, experience was just about all that mattered in
determining the course of development.
Watson did little research to support his claims, but B. F. Skinner (1904–1990) filled
this gap. Skinner studied operant conditioning, in which the consequences of a behavior
determine whether a behavior is repeated in the future. Skinner showed that two kinds
of consequences were especially influential. A reinforcement is a consequence that increases the future likelihood of the behavior that it follows. Positive reinforcement consists of giving a reward such as chocolate, gold stars, or paychecks to increase the likelihood of a previous behavior. A father who wants to encourage his daughter to help with
chores may reinforce her with praise, food treats, or money whenever she cleans her
room. Negative reinforcement consists of rewarding people by taking away unpleasant
things. The same father could use negative reinforcement by saying that whenever his
daughter cleans her room she doesn’t have to wash the dishes or fold laundry.
A punishment is a consequence that decreases the future likelihood of the behavior
that it follows. Punishment suppresses a behavior either by adding something aversive
or by withholding a pleasant event. Should the daughter fail to clean her room, the
father may punish her by nagging (adding something aversive) or by not allowing her
to watch television (withholding a pleasant event).
Skinner’s research was done primarily with animals, but human development researchers showed that the principles of operant conditioning could be extended readily
to people, too (Baer & Wolf, 1968). Applied properly, reinforcement and punishment
are indeed powerful influences on children, adolescents, and adults.
Social Learning Theory
imitation or observational learning
learning that occurs by simply watching
how others behave
Researchers discovered that people sometimes learn without reinforcement or punishment. People learn much by simply watching those around them, which is known as
imitation or observational learning. Imitation is occurring when one toddler throws
a toy after seeing a peer do so or when a school-age child offers to help an older adult
carry groceries because she’s seen her parents do the same.
Perhaps imitation makes you think of “monkey-see, monkey-do,” in which people
simply mimic what they see. Early investigators had this view too, but research quickly
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showed that this was wrong. People do not always imitate what they see around them.
People are more likely to imitate if the person they see is popular, smart, or talented.
They’re also more likely to imitate when the behavior they see is rewarded than when
it is punished. Findings like these imply that imitation is more complex than sheer
mimicry. People are not mechanically copying what they see and hear; instead, they
look to others for information about appropriate behavior. When peers are reinforced
for behaving in a particular way, this encourages imitation.
Albert Bandura (1925– ) based his social cognitive theory on this more complex
view of reward, punishment, and imitation. Bandura’s theory is “cognitive” because he
believes people actively try to understand what goes on in their world; the theory is
“social” because, along with reinforcement and punishment, what other people do is
an important source of information about the world.
Bandura also argues that experience gives people a sense of self-efficacy, which
refers to people’s beliefs about their own abilities and talents. Self-efficacy beliefs help
to determine when people will imitate others. A child who sees himself as not athletically talented, for example, will not try to imitate LeBron James dunking a basketball
despite the fact that LeBron is obviously talented and popular. Thus, whether an individual imitates others depends on who the other person is, on whether that person’s
behavior is rewarded, and on the individual’s beliefs about his or her own abilities.
Bandura’s social cognitive theory is a far cry from Skinner’s operant conditioning. The operant conditioned person who responds mechanically to reinforcement
and punishment has been replaced by the social cognitive person who actively interprets these and other events. Nevertheless, Skinner, Bandura, and all learning theorists
share the view that experience propels people along their developmental journeys.
These theorists would tell Betty that she can thank experience for making her son
Marcus both happy and successful academically.
Linda Cicero / Stanford News Service
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Albert Bandura
self-efficacy
people’s beliefs about their own abilities
and talents
| Cognitive-Developmental Theory
Another way to approach development is to focus on thought processes and the construction of knowledge. In cognitive-developmental theory, the key is how people
think and how thinking changes over time. Two distinct approaches have developed.
One approach postulates that thinking develops in a universal sequence of stages;
Piaget’s theory of cognitive development (and its recent extensions) is the best-known
example. The second approach proposes that people process information as computers do, becoming more efficient over much of the life span; information-processing
theory is an example of this view.
The cognitive developmental perspective focuses on how children construct knowledge and how their constructions change over time. Jean Piaget (1896–1980), who was
the most influential developmental psychologist of the 20th century, proposed the
best-known of these theories. Piaget believed that children naturally try to make sense
of their world. Throughout infancy, childhood, and adolescence, youngsters want to
understand the workings of both the physical and the social world. For example, infants want to know about objects: “What happens when I push this toy off the table?”
And they want to know about people: “Who is this person who feeds and cares for
me?” In their efforts to comprehend their world, Piaget argued that children act like
scientists, creating theories about the physical and social worlds. Children try to weave
all that they know about objects and people into a complete theory, which is tested
daily by experience because their theories lead children to expect certain things to
happen. As with real scientific theories, when the predicted events do occur, a child’s
belief in her theory grows stronger. When the predicted events do not occur, the child
must revise her theory.
Let’s take the perspective of an infant whose theory of objects includes the idea
that “Toys pushed off the table fall to the floor.” If the infant pushes some other
object—a plate or an article of clothing—she will find that it, too, falls to the floor, and
© Bettmann / Corbis
Piaget’s Theory
Jean Piaget
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● TABLE 1.2
Piaget’s Four Stages of Cognitive Development
Stage
Approximate Age
Characteristics
Sensorimotor
Birth to 2 years
Preoperational thought
2 to 6 years
Concrete operational
thought
Formal operational thought
7 years to early
adolescence
Adolescence and
beyond
Infant’s knowledge of the world is based on senses and motor skills;
by the end of the period, uses mental representation
Child learns how to use symbols such as words and numbers to
represent aspects of the world but relates to the world only through his or her
perspective
Child understands and applies logical operations to experiences
provided they are focused on the here and now
Adolescent or adult thinks abstractly, deals with hypothetical situations,
and speculates about what may be possible
T H INK ABO UT I T
Try to use the basic ideas of operant
conditioning (page 12) to explain how
children create theories of the physical
and social world.
© Michael Newman / PhotoEdit
information-processing theory
theory proposing that human cognition
consists of mental hardware and mental
software
Information-processing theory helps explain how
this girl learns, stores, and retrieves information
so she can pass this exam.
she can then make the theory more general: “Objects pushed off the table fall to the
floor.” Piaget also believed children begin to construct knowledge in new ways at a
few critical points in development. When this happens, they revise their theories radically. These changes are so fundamental that the revised theory is, in many respects,
a brand-new theory. Piaget claimed that these changes occur three times in development: once at about age 2 years, a second time at about age 7, and a third time just before adolescence. These changes mean that children go through four distinct stages in
cognitive development. Each stage represents a fundamental change in how children
understand and organize their environment, and each stage is characterized by more
sophisticated types of reasoning. For example, the first or sensorimotor stage begins at
birth and lasts until about 2 years of age. As the name implies, sensorimotor thinking
refers to an infant’s constructing knowledge through sensory and motor skills. This
stage and the three later stages are shown in ● Table 1.2.
Piaget’s theory has had an enormous influence on how developmentalists and
practitioners think about cognitive development. The theory has been applied in many
ways—from the creation of discovery learning toys for children to the ways teachers
plan lessons. In Chapter 4 we’ll see how Piaget explained thinking during infancy and
the preschool years; in Chapters 6 and 8 we’ll learn about his description of thinking
in school-age children and adolescents.
Information-Processing Theory
Information-processing theorists draw heavily on how computers work to explain
thinking and how it develops through childhood and adolescence. Just as computers
consist of both hardware (disk drives, random-access memory, and central processing
unit) and software (the programs it runs), information-processing theory proposes
that human cognition consists of mental hardware and mental software. Mental hardware refers to cognitive structures, including different memories where information is stored. Mental software includes
organized sets of cognitive processes that enable people to complete
specific tasks, such as reading a sentence, playing a video game, or hitting a baseball. For example, an information-processing psychologist
would say that, for a student to do well on an exam, she must encode
the information as she studies, store it in memory, and then retrieve
the necessary information during the test.
How do information-processing psychologists explain developmental changes in thinking? To answer this question, think about
improvements in personal computers. Today’s personal computers
can accomplish much more than computers built just a decade ago.
Why? Today’s computers have better hardware (e.g., more memory
and a faster processor) as well as more sophisticated software that
takes advantage of the better hardware. Like modern computers, older children and
adolescents have better hardware and better software than younger children, who are
more like last year’s out-of-date model. For example, older children typically solve
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math word problems better than younger children because they have greater memory
capacity to store the facts in the problem and because their methods for performing
arithmetic operations are more efficient.
Some researchers also point to deterioration of the mental hardware—along with
declines in the mental software—as explanations of cognitive aging. In Chapter 14 we
will see, for example, that normal aging brings with it significant changes in people’s
ability to process information.
Lev Vygotsky (1896–1934) was one of the first theorists to emphasize that children’s
thinking does not develop in a vacuum but rather is influenced by the sociocultural
context in which children grow up. A Russian psychologist, Vygotsky focused on ways
that adults convey to children the beliefs, customs, and skills of their culture. Vygotsky
believed that, because a fundamental aim of all societies is to enable children to acquire essential cultural values and skills, every aspect of a child’s development must
be considered against this backdrop. For example, most parents in the United States
want their children to work hard in school and be admitted to college because earning
a degree is one of the keys to finding a good job. However, in Mali (an African country), Bambara parents want their children to learn to farm, herd animals such as cattle
and goats, gather food such as honey, and hunt because these skills are key to survival
in their environment. Vygotsky viewed development as an apprenticeship in which
children develop as they work with skilled adults, including teachers and parents.
For Piaget, information-processing theorists, and Vygotsky, children’s thinking becomes more sophisticated as they develop. Piaget explained this change as resulting
from the more sophisticated knowledge that children construct from more sophisticated thinking; information-processing psychologists attribute it to more sophisticated
mental hardware and mental software. What would these theorists say to Betty about
Marcus’s good nature? Vygotsky would point out that Betty communicated key aspects
of the culture to Marcus, which influenced his good nature. Neither Piaget nor information-processing theorists would have much to say, since their theories do not handle
personality issues very well. What about Marcus’s academic success? That’s a different
story. Piaget would explain that all children naturally want to understand their world;
Marcus is simply unusually skilled in this regard. An information-processing psychologist would point to superior hardware and superior software as the keys to his academic
success. Vygotsky would again emphasize Betty’s influence in cultural transmission.
© Felicia Martinez / PhotoEdit
Vygotsky’s Theory
Lev Vygotsky
Most developmentalists agree that the environment is an important force in many
aspects of development. However, only ecological theories (which get their name from
the branch of biology dealing with the relation of living things to their environment
and to one another) have focused on the complexities of environments and their links
to development. In ecological theory, human development is inseparable from the
environmental contexts in which a person develops. The ecological approach proposes
that all aspects of development are interconnected, much like the threads of a spider’s
web are intertwined, so that no aspect of development can be isolated from others
and understood independently. An ecological theorist would emphasize that, to understand why adolescents behave as they do, we need to consider the many different
systems that influence them, including parents, peers, teachers, television, the neighborhood, and social policy.
We will consider two examples of the ecological and systems approach: Bronfenbrenner’s theory and the competence–environmental press framework.
Bronfenbrenner’s Theory
The best-known proponent of the ecological approach was Urie Bronfenbrenner
(1917–2005), who proposed that the developing person is embedded in a series of
complex and interactive systems (Bronfenbrenner, 1979, 1989, 1995). Bronfenbrenner
AP Images
| The Ecological and Systems Approach
Urie Bronfenbrenner
ecological theory
theory based on idea that human development is inseparable from the environmental contexts in which a person develops
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❚ Figure 1.2
Bronfenbrenner’s ecological approach emphasizes the interaction across different systems
in which people operate.
Macrosystem
Exosystem
Child
Ethnic group
Parents
Friends
School
Pare
nts’ places of
employment
Historical
events
Microsystem
Go v
ernment and
social policy
osystem
M es
Paren
ts’ social
network
Culture
Adapted from The Child: Development in a Social Context, by Claire B. Kopp and
Joanne B. Krakow, p. 648.
microsystem
the people and objects in an individual’s
immediate environment
mesosystem
provides connections across microsystems
exosystem
social settings that a person may not experience firsthand but that still influence
development
macrosystem
the cultures and subcultures in which the
microsystem, mesosystem, and exosystem
are embedded
divided the environment into the four levels shown in ❚ Figure 1.2: the microsystem,
the mesosystem, the exosystem, and the macrosystem.
At any point in life, the microsystem consists of the people and objects in an individual’s immediate environment. These are the people closest to a child, such as parents or siblings. Some children may have more than one microsystem; for example, a
young child might have the microsystems of the family and of the day-care setting. As
you can imagine, microsystems strongly influence development.
Microsystems themselves are connected to create the mesosystem. The mesosystem
provides connections across microsystems, because what happens in one microsystem
is likely to influence others. Perhaps you’ve found that if you have a stressful day at
work or school then you’re often grouchy at home. This indicates that your mesosystem is alive and well; your microsystems of home and work are interconnected
emotionally for you.
The exosystem refers to social settings that a person may not experience firsthand
but that still influence development. For example, changes in government policy regarding welfare may mean that poor children have less opportunity for enriched preschool experiences. Although the influence of the exosystem is no more than secondhand, its effects on human development can be quite strong.
The broadest environmental context is the macrosystem, the cultures and subcultures in which the microsystem, mesosystem, and exosystem are embedded. A mother,
her workplace, her child, and the child’s school are part of a larger cultural setting,
such as Asian Americans living in Southern California or Italian Americans living in
large cities on the East Coast. Members of these cultural groups share a common identity, a common heritage, and common values. The macrosystem evolves over time;
each successive generation may develop in a unique macrosystem.
Bronfenbrenner’s ecological theory emphasizes the many levels of influence on
human development. People are affected directly by family members and friends and
indirectly by social systems such as neighborhoods and religious institutions—which,
in turn, are affected by the beliefs and heritage of one’s culture.
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Competence–Environmental Press Theory
Another view of the influence of environments on human development comes from
Lawton and Nahemow’s (1973) competence–environmental press theory. According to
this theory, people adapt most effectively when there is a good match between their
competence or abilities and the environmental “press,” or the demands put on them
by the environment. This theory was originally proposed to account for the ways in
which older adults function in their environment, but it applies as well throughout the
life span. For example, the match between a child’s social skills and her peer group’s
demands can determine whether she is accepted by the peer group. As with Bronfenbrenner’s theory, competence–environmental press theory emphasizes that, in order
to understand people’s functioning, it is essential to understand the systems in which
they live.
Ecological theorists would agree with learning theorists in telling Betty that the
environment has been pivotal in her son’s amiable disposition and his academic
achievements. However, the ecological theorist would insist that environment means
much more than the reinforcements, punishments, and observations that are central
to learning theory; such a theorist would emphasize the different levels of environmental influence on Marcus. Betty’s ability to balance home (microsystem) and work
(mesosystem) so skillfully (which meant that she was usually in a good mood herself)
contributed positively to Marcus’s development, as did Betty’s membership in a cultural group (exosystem) that emphasized the value of doing well in school.
Life-Span Perspective, Selective Optimization With
Compensation, and Life-Course Perspective
Most of the theories of human development that we have considered so far pay little
attention to the adult years of the life span. Historically, adulthood was downplayed
owing to the belief that it was a time when abilities had reached a plateau (rather
than continuing to develop) and that adulthood was followed by inevitable decline in
old age. However, modern perspectives emphasize the importance of viewing human
development as a lifelong process. These perspectives view development in terms of
where a person has been and where he or she is heading.
Life-Span Perspective and Selective Optimization With Compensation
■
Multidirectionality. Development involves both growth and decline; as people
grow in one area they may lose in another and at different rates. For example,
life-span perspective
view that human development is multiply
determined and cannot be understood
within the scope of a single framework
Courtesy of Paul Baltes / Center of Lifespan Psychology at the Max Planck Institute
for Human Development
What would it be like to try to understand your best friend without knowing anything
about his or her life? We cannot understand adults’ experiences without appreciating
their childhood and adolescence. Placing adults’ lives in this broader context is what
the life-span perspective does.
According to the life-span perspective, human development is multiply determined
and cannot be understood within the scope of a single framework. The basic premises
of the life-span perspective is that aging is a lifelong process of growing up and growing old, beginning with conception and ending with death. No single period of a person’s life (such as childhood, adolescence, or middle age) can be understood apart from
its origins and its consequences. To understand a specific period, we must know what
came before and what is likely to come afterward (Riley, 1979). In addition, how one’s
life is played out is affected by social, environmental, and historical change. Thus, the
experiences of one generation may not be the same as those of another.
Paul Baltes (1939–2006) and colleagues provide many of the main approaches to
human development from a life-span perspective (Baltes, 1987; Baltes, Lindenberger, &
Staudinger, 2006; Baltes & Smith, 2003) in a model that has influenced a wide range of
research, especially on adult development and aging. A key point in their model is that
human development is complex and cannot be understood from a single discipline.
They identify four key features of the life-span perspective as follows.
Paul Baltes
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■
■
■
selective optimization with
compensation (SOC) model
model in which three processes (selection,
optimization, and compensation) form a
system of behavioral action that generates
and regulates development and aging
people’s vocabulary ability tends to increase throughout life, but reaction time
tends to slow down.
Plasticity. One’s capacity is not predetermined or carved in stone. Many skills
can be learned or improved with practice, even in late life. For example, people can learn ways to help themselves remember information, which may help
them deal with the declines in memory ability that accompany aging. There
are limits to the degree of potential improvement, though, as described in later
chapters.
Historical context. Each of us develops within a particular set of circumstances
determined by the historical time in which we are born and the culture in
which we grow up. For example, living in a middle-class suburb in 1950s
Indianapolis has little in common with living in a poor Latino neighborhood
in 1990s Texas.
Multiple causation. How we develop results from biological, psychological, sociocultural, and life-cycle forces, which we mentioned previously in this chapter. For example, two children growing up in the same family will have different experiences if one has a developmental disability and the other does not.
Based on these principles, Baltes and colleagues (2006) propose that life-span development consists of the dynamic interplay between growth, maintenance, and loss
regulation.
Taken together, the principles of the life-span perspective create a way to describe
and explain the successful adaptation of people to the changes that occur with aging by proposing an interaction between three processes: selection, compensation,
and optimization (Baltes, 1997; Baltes et al., 2006; B. Baltes & Heydens-Gahir, 2003;
M. Baltes & Carstensen, 1999). Selection processes serve to choose goals, life domains,
and life tasks, whereas optimization and compensation concern maintaining or enhancing chosen goals. The basic assumption of the selective optimization with compensation (SOC) model is that the three processes form a system of behavioral action
that generates and regulates development and aging.
As people mature and grow old, they select from a range of possibilities or opportunities. This selection occurs for two main reasons. Elective selection occurs when
one chooses to reduce one’s involvement to fewer domains as a result of new demands
or tasks, such as when a college student drops out of some organizations because of
the amount of work required in the courses she is taking that term. Loss-based selection occurs when this reduced involvement happens as a result of anticipated losses
in personal or environmental resources, such as when an older person stops going to
church because he can no longer drive. In either case, selection can involve the continuation of previous goals on a lesser scale or the substitution of new goals, and it
may be either proactive or reactive.
Compensation occurs when a person’s skills have decreased so that they no longer
function well in a particular domain. When a person compensates, she searches for an
alternative way to accomplish the goal; for example, if an injury reduces one’s ability
to drive then one might compensate by taking the bus. Sometimes, compensation requires learning a new skill; for example, an older adult who is experiencing short-term
memory problems might compensate by learning to use a personal digital assistant.
Thus, compensation differs from selection in that the task or goal is maintained—
although other means are used to achieve it.
Optimization involves minimizing losses and maximizing gains. The main idea
is to find the best match possible between one’s resources (biological, psychological,
and sociocultural) and one’s desired goals. Because people cannot achieve optimal outcomes in everything, development becomes a dynamic process of selecting the right
goals and compensating when possible to help maximize the odds of achieving them.
One can see the SOC model at work in many situations. For example, aging musicians may reduce the number of pieces they play (selection), rehearse them more
often (optimization), and sing them in a lower key (compensation). This way, they can
continue playing concerts later in life. A college athlete who excels at ice hockey and
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baseball may decide to concentrate on hockey (selection), work on training all year
(optimization), and develop a wicked wrist shot to make up for a mediocre slap shot
(compensation).
The life-span perspective and the SOC model have provided important approaches
to the contemporary study of human development. The emphasis on the need for a
multidisciplinary approach and for recognizing many interactive forces will be developed throughout this text.
Life-Course Perspective
Adults often describe their lives as a story that includes several key life transitions
(e.g., going to school, getting a first job, getting married, having children). Such stories
show how people move through their lives and experience unique interactions of the
four forces of development.
The life-course perspective describes the ways in which various generations experience the biological, psychological, and sociocultural forces of development in their
respective historical contexts. Specifically, it lets researchers examine the effects of historical time on how people create their lives (Dannefer & Miklowski, 2006; Hagestad
& Dannefer, 2001; Hareven, 1995, 2002). A key feature of the life-course perspective is
the dynamic interplay between the individual and society. This interplay creates three
major dimensions, which all involve timing and underlie the life-course perspective:
■
■
■
life-course perspective
description of how various generations
experience the biological, psychological,
and sociocultural forces of development in
their respective historical contexts
The individual timing of life events in relation to external historical events. This
dimension addresses the question: How do people time and sequence their
lives (e.g., getting a first job) in the context of changing historical conditions
(e.g., economic good times or recession)?
The synchronization of individual transitions with collective familial ones.
This dimension addresses the question: How do people balance their own
lives (e.g., work obligations) with those of their family (e.g., children’s soccer
games)?
The impact of earlier life events, as shaped by historical events, on subsequent
ones. This dimension addresses the question: How does experiencing an event
earlier in life (e.g., a male turning 18 years old) at a particular point in history
(e.g., when there is a military draft) affect one’s subsequent life (e.g., choosing
a particular career)?
Research from the life-course perspective has clearly shown that major life transitions
such as marriage, childbearing, starting and ending a career, and completing one’s education occur at many different ages across people and generations. These differences
first appear after adolescence, when people begin to have much more control over the
course of their lives. Research has also shown that life transitions are more continuous and multidirectional than previously thought. For example, completing an education was relegated to early adulthood in traditional models, yet current trends toward
lifelong learning make this view obsolete. Finally, research shows that the various
domains of people’s lives are highly interdependent; for example, the decision to have
a child is often made in the context of where one is in one’s career and education.
The emphasis in the life course perspective on interrelations between the individual and society with reference to historical time has made it a dominant view in the
social sciences. In particular, this approach is useful in helping researchers understand
how the various aspects of people’s experiences (work, family, education) interact to
create unique lives.
Overall, life-span and life-cycle theories have greatly enhanced the general body of
developmental theory by drawing attention to the role of aging in the broader context of
human development. These theories have played a major role in conceptualizing adulthood and have greatly influenced the research we consider in Chapters 10 through 15.
Theorists espousing a life-span or life-course perspective would tell Betty that Marcus
will continue to develop throughout his adult years and that this developmental journey will be influenced by biopsychosocial forces, including his own family.
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● TABLE 1.3
Theoretical Perspectives on Human Development
Emphases in
Biopsychosocial
Framework
Positions on
Developmental
Issues
Nature–nurture
interaction, discontinuity, universal
sequence but individual
differences in rate
In all theories,
strongly nurture,
continuity, and universal principles of
learning
Perspective
Examples
Main Idea
Psychodynamic
Erikson’s psychosocial theory
Personality develops through
sequence of stages
Psychological, social,
and life-cycle forces
crucial; less emphasis
on biological
Learning
Behaviorism
(Watson, Skinner)
Environment controls
behavior
In all theories, some
emphasis on biological and psychological, major focus on
social, little recognition of life cycle
Social learning
theory (Bandura)
Piaget’s theory
(and extensions)
People learn through modeling and observing
For Piaget, thinking develops
in a sequence of stages
Informationprocessing
theory
Thought develops by
increases in efficiency at
handling information
Vygotsky’s theory
Development influenced by
culture
Bronfenbrenner’s
theory
Developing person embedded in a series of interacting systems
Competence–
environmental
press (Lawton
and Nahemow)
Baltes’s life-span
perspective and
selective optimization with
compensation
(SOC)
Life-course
theory
Adaptation is optimal when
ability and demands are in
balance
Cognitive
Ecological and Systems
Life-Span
Perspective/SOC
and
Life-Course Perspective
Development is multiply
determined; optimization
of goals
Life course transitions
decreasingly tied to age;
increased continuity over
time; specific life paths across
domains are interdependent
For Piaget main
emphasis on biological and social forces,
less on psychological,
little on life cycle
Emphasis on biological and psychological, less on social and
life cycle
Emphasis on psychological and social
forces
Low emphasis on
biological, moderate
on psychological and
life cycle, heavy on
social
Strong emphasis on
biological, psychological, and social,
moderate on life cycle
Strong emphasis on
the interactions of
all four forces; cannot consider any in
isolation
Strong emphasis on
psychological, sociocultural, life cycle;
less on biological
For Piaget, strongly
nature, discontinuity, and universal
sequence of stages
Nature–nurture
interaction, continuity,
individual differences
in universal structures
Nature–nurture
interaction, continuity, individual differences
Nature–nurture interaction, continuity, context-specific
Nature–nurture interaction, continuity, context-specific
Nature–nurture interaction, continuity
and discontinuity,
context-specific
Nature–nurture interaction, continuity
and discontinuity,
context-specific
| The Big Picture
As summarized in ● Table 1.3, each of the theories provides ways of explaining how the
biological, psychological, sociocultural, and life-cycle forces create human development.
But because no single theory provides a complete explanation of all aspects of development, we must rely on the biopsychosocial framework to help piece together an account
based on many different theories. Throughout the remainder of this text, you will read
about many theories that differ in focus and in scope. To help you understand them better, each theory will be introduced in the context of the issues that it addresses.
Because one of the criteria for a theory is that it be testable, developmentalists
have adopted certain methods to help accomplish this. The next section describes the
methods by which developmentalists conduct research and test their theories.
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Test Yourself
3.
4.
5.
6. A belief that human development is characterized by
multidirectionality and plasticity is fundamental to the
perspective.
INTERPRET
How are the information-processing perspective and
Piaget’s theory similar? How are they different?
APPLY
Using three different developmental theories, explain how
Johnny Depp or Queen Latifah achieved their success.
Recall answers: (1) Theories, (2) psychosocial, (3) observing others, (4) informationprocessing, (5) microsystem, (6) life-span
2.
RECALL
1.
organize knowledge in order to provide testable explanations of human behaviors and the
ways in which they change over time.
The
perspective proposes that development is determined by the interaction of an internal
maturational plan and external societal demands.
According to social cognitive theory, people learn
from reinforcements, from punishments, and through
.
Piaget’s theory and
theory are
examples of the cognitive-developmental perspective.
According to Bronfenbrenner, development occurs in the
context of the
, mesosystem, exosystem, and macrosystem.
1.3 DOING DEVELOPMENTAL RESEARCH
L E AR N I N G OB J E C T I V E S
❚ How do scientists measure topics of interest in studying human development?
❚ What research designs are used to study human
development?
❚ How do researchers integrate results from multiple studies?
❚ What ethical procedures must researchers follow?
❚ How do investigators communicate results from research
studies?
❚ How does research affect public policy?
L
eah and Joan are both mothers of 10-year-old boys. Their sons have many friends, but the
basis for the friendships is not obvious to the mothers. Leah believes “opposites attract”—
children form friendships with peers who have complementary interests and abilities. Joan
doubts this; her son seems to seek out other boys who are near clones of himself in terms of
interests and abilities.
SUPPOSE LEAH AND JOAN KNOW THAT YOU’RE TAKING A COURSE IN HUMAN DEVELOPMENT, so they ask you to settle their argument. Leah believes complementary children
are more often friends, whereas Joan believes similar children are more often friends.
You know that research could show whose ideas are supported under which circumstances, but how? In fact, human development researchers must make several important decisions as they prepare to study a topic. They need to decide how to measure
the topic of interest; they must design their study; they must choose a method for
studying development; and they must decide whether their plan respects the rights of
individuals participating in the research.
Human development researchers do not always stick to this sequence of steps.
For example, often researchers consider the research participants while making other
decisions—perhaps rejecting a measurement procedure because it violates the rights
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of participants. Nevertheless, for simplicity we will adhere to this sequence as we describe each of the steps in doing developmental research.
| Measurement in Human Development Research
Researchers usually begin by deciding how to measure the topic or behavior of interest. For example, the first step toward answering Leah and Joan’s question about
friendships would be to decide how to measure friendships.
Human development researchers typically use one of four approaches: observing
systematically, using tasks to sample behavior, asking people for self-reports, and taking physiological measures.
Systematic Observation
systematic observation
watching people and carefully recording
what they do or say
naturalistic observation
technique in which people are observed as
they behave spontaneously in some reallife situation
structured observations
technique in which a researcher creates a
setting that is likely to elicit the behavior
of interest
As the name implies, systematic observation involves watching people and carefully
recording what they do or say. Two forms of systematic observation are common. In
naturalistic observation, people are observed as they behave spontaneously in some
real-life situation. Of course, researchers can’t keep track of everything that someone
does, so beforehand they must decide what variables to record. For example, researchers studying friendship might decide to observe children at the start of the first year
in a middle school (chosen because many children will be making new friends at this
time). They could decide to record where children sit in the lunchroom and who talks
to whom.
Structured observations differ from naturalistic observations in that the researcher
creates a setting that is likely to elicit the behavior of interest. Structured observations
are particularly useful for studying behaviors that are difficult to observe naturally.
Some phenomena, such as emergencies, rarely occur. An investigator relying on natural
observations to study people’s responses to emergencies wouldn’t make much progress
with naturalistic observation because emergencies don’t occur at predetermined times
and locations. However, using a structured observation, an investigator might stage an
emergency—perhaps cooperating with authorities to simulate an accident—in order
to observe other people’s responses.
Other behaviors are difficult for researchers to observe because they occur in private settings, not public ones. For example, much interaction between friends takes
place at home, where it would be difficult for investigators to observe unobtrusively.
However, friends could be asked to come to the researcher’s laboratory, which might be
furnished to resemble a family room in a typical house. Friends would then be asked
to perform some activity typical of friends, such as discussing a problem together or
deciding what movie to see. The researchers would then observe their activity from
another room, through a one-way mirror, or by videotaping them.
Structured observations are valuable in enabling researchers to observe behavior(s)
that would otherwise be difficult to study. However, investigators using this approach
must be careful that the settings they create allow the behaviors to be as realistic as
possible. For example, observing friends as they discuss a problem in a mock family
room has many artificial aspects to it: The friends are not in their own homes, they
were told in general terms what to do, and they know they’re being observed. Any
of these factors may cause friends to behave differently than they would in the real
world. Researchers must be careful that their method does not distort the behavior
they are observing.
Sampling Behavior With Tasks
When investigators can’t observe a behavior directly, another popular alternative is
to create tasks that are thought to sample the behavior of interest. One task often
used to measure older adults’ memory is “digit span”: Adults listen as a sequence of
digits is presented aloud. After the last digit is presented, they try to repeat the digits
in order.
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❚ Figure 1.3
In this example of sampling behavior with
tasks, the child is to select the face that looks
happy.
Another example is shown in ❚ Figure 1.3. To study the ability to recognize emotions, the child has been asked to look at the photographs and point to the face that
looks happy. A child’s answers on this sort of task are useful in determining his or
her ability to recognize emotions. This approach is popular with human development
researchers primarily because it is so convenient. A potential problem with this approach, however, is that the task may not provide a realistic sample of the behavior of
interest. For example, asking children to judge emotions from photographs may not
be valid because it underestimates what they do in real life. Can you think of reasons
why this might be the case? We mention several reasons on page 35, just after Test
Yourself.
Self-Reports
Self-reports actually represent a special case of using tasks to measure people’s behavior. Self-reports are simply people’s answers to questions about the topic of interest.
When questions are posed in written form, the self-report is a questionnaire; when
questions are posed orally, the self-report is an interview. In either format, questions
are created that probe different aspects of the topic of interest. For example, if you believe that children are more often friends when they have interests in common, then
you might tell your research participants the following:
self-reports
people’s answers to questions about the
topic of interest
Tom and Dave just met each other at school. Tom likes to read, plays the clarinet
in the school orchestra, and is not interested in sports; Dave likes to instant message his friends, enjoys tinkering with his car, and is a star on the football team.
Do you think Tom and Dave will become friends?
The participants would then decide, perhaps using a rating scale, whether the boys are
likely to become friends.
Self-reports are useful because they can lead directly to information on the topic
of interest. They are also relatively convenient, particularly when they can be administered to groups of participants.
However, self-reports are not always a good measure of people’s behavior because
not all answers are accurate. Why? When asked about past events, people may not
remember them accurately. For example, an older adult asked about adolescent friends
may not remember those friendships well. Sometimes people answer incorrectly as a
result of “response bias”: For many questions, some responses are more socially acceptable than others, and people are more likely to select socially acceptable answers
T HIN K ABO U T IT
If you were studying middle-aged
adults caring for their aging parents,
what would be the relative advantages
of systematic observation, sampling
behavior with tasks, and self-reports?
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❚ Figure 1.4
Brain imaging techniques provide a physiological measure that helps researchers
understand brain-behavior relations.
than socially unacceptable ones. For example, many would be reluctant to admit that
they have no friends at all. As long as investigators remain aware of these potential
biases, self-report can be a valuable tool for research in human development.
Physiological Measures
© Volker Steger / Peter Arnold Inc.
One less common but potentially powerful form of measurement is measuring people’s physiological responses. Heart rate, for example, often slows down when people
are paying close attention to something interesting. Consequently, researchers often
measure heart rate to determine a person’s degree of attention. As another example,
the hormone cortisol is often secreted in response to stress. By measuring cortisol levels in people’s saliva, scientists can determine when they are experiencing stress.
As both of these examples suggest, physiological measures are usually specialized—
they focus on a particular aspect of a person’s behavior (attention and stress in the
two examples). What’s more, they’re often used with other behaviorally oriented
methods. A researcher studying stress might observe several people for overt signs
of stress, ask parents/partners/friends to rate the target people’s stress, and also measure cortisol in the target people’s saliva. If all three measures lead to the same conclusions about stress, then the researcher can be much more confident about those
conclusions.
Another important type of physiological measure includes those used to study
brain activity. Techniques developed since the 1980s allow today’s scientists to record
many facets of brain functioning in real time as subjects perform specific tasks. Neuroscientists are making great strides in identifying the brain regions associated with
reasoning, memory, emotions, and other psychological functions. ❚ Figure 1.4 shows
an image of brain activity used in this type of research.
The strengths and weaknesses of the four approaches to measurement are summarized in ● Table 1.4.
Reliability and Validity
reliability
extent to which a measure provides a
consistent index of a characteristic
validity
extent to which a measure actually
assesses what researchers think it does
After researchers choose a method, they must show that it is both reliable and valid.
The reliability of a measure is the extent to which it provides a consistent index of a
characteristic. A measure of friendship, for example, is reliable if it gives a consistent
estimate of a person’s friendship network each time you administer it.
The validity of a measure refers to whether it really measures what researchers
think it measures. For example, a measure of friendship is valid only if it can be shown
to actually measure friendship (and not length, for example). Validity is often established by showing that the measure in question is closely related to another measure
that is known to be valid. Because a measure can be reliable but not valid (e.g., a ruler
is a reliable measure of length but not a valid measure of friendship), researchers must
ensure that their measures are both reliable and valid.
● TABLE 1.4
Measuring Behaviors of Interest in Human Development Research
Method
Systematic observation
Naturalistic observation
Structured observation
Sampling behavior
with tasks
Self-reports
Physiological measures
Strength
Weakness
Captures people’s behavior in its natural
setting
Can be used to study behaviors that are rare
or that typically occur in private settings
Convenient—can be used to study most
behaviors
Convenient—can be used to study most
behaviors
Provide a more direct measure of underlying
behavior
Difficult to use with behaviors that are rare or
that typically occur in private settings
May be invalid if structured setting distorts
the behavior
May be invalid if the task does not sample
behavior as it occurs naturally
May be invalid because people answer incorrectly (due to either forgetting or response bias)
Highly specific in what they measure and thus
cannot be applied broadly
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Throughout this book, you’ll see many studies using different methods and also that
studies of the same topic or behavior often use different methods. In other words, each
of the approaches will be used in different studies. Multiple approaches to measurement have different strengths and weaknesses, so finding the same results regardless of
the approach leads to particularly strong conclusions.
Representative Sampling
Valid measures also depend on the people who are tested. Researchers are usually interested in broad groups of people called populations. Examples of populations would
be all American 7-year-olds or all African American grandparents. Virtually all studies include only a sample of people, which is a subset of the population. Researchers
must take care that their sample really is representative of the population of interest,
because an unrepresentative sample can lead to invalid conclusions. For example, if
you discovered that a study of friendship in older adults tested only adults who had
no siblings, you would probably decide that this sample is not representative of the
population of older adults and question the validity of its results.
As you read on, you’ll soon discover that much of the research we describe was
conducted with samples of middle-class European American people. Are these samples representative of all people in the United States? Of all people in the world?
Sometimes, but not always. Be careful not to assume that findings from this group
necessarily apply to people in other groups. Additionally, some developmental issues
have not been studied in all ethnic and racial groups. For example, the U.S. government does not consistently break down its reported statistics by ethnic group.
In an effort to make samples more representative, some federal agencies now require the inclusion of certain groups unless there is a compelling reason not to do
so. For example, the National Institutes of Health require the inclusion of ethnic minorities, women, and children in the research they sponsor. These steps may make it
possible to obtain a broader view of developmental processes. Until we have representative samples in all developmental research, we cannot know whether a particular
phenomenon applies only to the group studied or to people more generally.
populations
broad groups of people that are of interest
to researchers
sample
a subset of the population
| General Designs for Research
Having selected a way to measure the topic or behavior of interest, researchers must
next embed this measure in a research design that yields useful, relevant results. Human development researchers rely on two primary designs in planning their work:
correlational studies and experimental studies.
Correlational Studies
In a correlational study, investigators look at relations between variables as they exist
naturally in the world. In the simplest possible correlational study, a researcher would
measure two variables and then see how they are related. Imagine a researcher who
wants to test the idea that smarter people have more friends. To test this claim, the
researcher would measure two variables for each person: the number of friends that
the person has and the person’s intelligence.
The results of a correlational study are usually measured by calculating a correlation coefficient, which expresses the strength and direction of a relation between two
variables. Correlations can range from −1.0 to 1.0 and reflect one of three possible relations between intelligence and the number of friends:
■
■
correlational study
investigation looking at relations between
variables as they exist naturally in the
world
correlation coefficient
an expression of the strength and direction of a relation between two variables
People’s intelligence is unrelated to the number of friends they have. In this
case, there is no relation between the variables and so the correlation is 0.
People who are smart tend to have more friends than people who are not as
smart. That is, more intelligence is associated with having more friends. In this
case, the variables are positively related and so the correlation is between
0 and 1.
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❚ Figure 1.5
There are three basic interpretations of a
correlation coefficient because there is no
direct way to assess cause and effect.
1 The first variable causes the second variable.
Being smart
Having more friends
2 The second variable causes the first variable.
Having more friends
3 Neither variable is caused by the other;
both are caused by a third variable that
was not measured in the study.
Being smart
Children who are smart
Parents who are warm
and supportive
Children who have
more friends
■
experiment
a systematic way of manipulating the
key factor(s) that the investigator thinks
causes a particular behavior
independent variable
the factor being manipulated
dependent variable
the behavior being observed
People who are smart tend to have fewer friends than people who are not as
smart. That is, more intelligence is associated with having fewer friends. In
this case, the variables are negatively related and so the correlation is between
−1 and 0.
In interpreting a correlation coefficient, you need to consider both the sign and
the size of the correlation. The sign indicates the direction of the relation between
variables: a positive sign means that larger values of one variable are associated with
larger values of the second variable, whereas a negative sign means that larger values
of one variable are associated with smaller values of the second variable.
The size or strength of a relation is measured by how much the correlation differs
from 0, either positively or negatively. A correlation of .9 between intelligence and
number of friends would indicate a very strong relation: Knowing a person’s intelligence, you could accurately predict how many friends the person has. If instead the
correlation were only .3, then the link between intelligence and number of friends
would be relatively weak: Although more intelligent people would have more friends
on average, there would be many exceptions to this rule. Similarly, a correlation of −.9
would indicate a strong negative relation between intelligence and number of friends
whereas a correlation of −.3 would indicate a weak negative relation.
A researcher conducting a correlational study can determine whether the variables are related. However, this design doesn’t address the question of cause and effect
between the variables. For example, suppose a researcher finds that the correlation
between intelligence and number of friends is .7. This would mean that people who
are smarter have more friends than people who are not as smart. How would you
interpret this correlation? ❚ Figure 1.5 shows that three interpretations are possible.
First, perhaps being smart causes people to have more friends. Another interpretation is that having more friends causes people to be smarter. A third interpretation is
that neither variable causes the other; instead, intelligence and number of friends are
caused by a third variable that was not measured in the study. Perhaps parents who
are warm and supportive tend to have children who grow up to both be smarter and
have many friends. Any of these interpretations could be true, but they cannot be distinguished in a correlational study. Investigators who wish to track down causes must
resort to a different design, called an experimental study.
Experimental Studies
An experiment is a systematic way of manipulating the key factor(s) that the investigator thinks causes a particular behavior. The factor being manipulated is called the
independent variable; the behavior being observed is called the dependent variable.
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❚ Figure 1.6
© Peter Foester / dpa / Landov
An experiment examining driving skills of
older drivers being conducted in a driving
simulator. In this “no phone” condition, the
driver is not talking on a mobile phone.
In human development, an experiment requires that the investigator begin with one
or more treatments, circumstances, or events (independent variables) that are thought
to affect behavior. People are then assigned randomly to conditions that differ in the
treatment they are given. Finally, an appropriate measure (the dependent variable) is
taken of all participants to see whether the treatment or treatments had the expected
effect. Because each person has an equal chance of being assigned to each treatment
condition (the definition of random assignment), any differences between the groups
can be attributed to the differential treatment people received in the experiment rather
than to other factors.
Suppose, for example, that an investigator believes older adults perform better in a
driving simulator when they are not talking on a mobile phone during the drive. ❚ Figure 1.6 shows how we might test this hypothesis. Older adults come to the laboratory,
where they are randomly assigned to a driving simulation during which they either do
or do not talk on a mobile phone.
All participants take the same driving test under circumstances that are held as
constant as possible—except for the presence or absence of the mobile phone. If scores
on the driving test are, on average, better in the “no phone” condition than in the
“mobile phone” condition, then the investigator may say with confidence that the mobile phone has a negative effect on driving skill. Conclusions about cause and effect are
possible in this example because the direct manipulation occurred under controlled
conditions.
Human development researchers usually conduct experiments in laboratory-like
settings because this allows full control over the variables that may influence the outcome of the research. A shortcoming of laboratory work is that the behavior of interest
is not studied in its natural setting. For example, performance on a driving simulator
may not be the same as actual driving performance. Consequently, there is always the
potential problem that the results may be invalid because they are artificial—specific
to the laboratory setting and not representative of the behavior in the “real world.”
Each research design used by developmentalists has both strengths and weaknesses. There is no one best method. Consequently, no single investigation can definitively answer a question. Researchers rarely rely on one study or even one method
to reach conclusions. Instead, they prefer to find converging evidence from as many
different kinds of studies as possible.
Qualitative Studies
Suppose you live near a children’s playground. Each day, you watch the children play
various games with each other and on the swings and sliding board. Because you are
interested in learning more about how children go about playing, you decide to watch
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qualitative research
method that involves gaining in-depth
understanding of human behavior and
what governs it
more carefully. With the parents’ permission, you digitally record the children’s play
each day for several weeks. You then watch the videos and notice whether there are
specific patterns that emerge.
What you have done is to conduct one type of qualitative research, which involves
gaining in-depth understanding of human behavior and what governs it. Unlike quantitative research, qualitative research seeks to uncover reasons underlying various aspects of behavior. Because qualitative research typically involves intensive observation of behavior over extended periods of time, the need is for smaller but focused
samples rather than large random samples. Frequently used techniques include video
recording and detailed interviews, from which qualitative researchers categorize the
data into patterns as the primary basis for organizing and reporting results. In contrast, quantitative research relies on numerical data and statistical tests as the bases
for reporting results.
Qualitative research can be conducted for its own sake, as a preliminary step, or
as a complement to quantitative research. Research reports of qualitative research are
usually richer and provide more details about the behavior being observed.
| Designs for Studying Development
Sometimes human development research is directed at a single age group, such as studying adolescent students to determine the impact of music on study habits. Or we might
examine retirement planning in 55-year-olds or marital satisfaction in couples married
at least 25 years. In each of these cases—after deciding how to measure the behavior of
interest and whether the study will be correlational or experimental—the investigator
could skip directly to the last step: determining whether the study is ethical.
However, much research in human development concerns changes that occur as
people develop. In these cases, investigators must also choose one of three designs that
allow them to examine development: longitudinal, cross-sectional, or sequential.
Longitudinal Studies
longitudinal study
longitudinal study research design in
which the same individuals are observed
or tested repeatedly at different points in
their lives
microgenetic study
a special type of longitudinal design in
which participants are tested repeatedly
over a span of days or weeks, typically
with the aim of observing change directly
as it occurs
In a longitudinal study, the same individuals are observed or tested repeatedly at
different points in their lives. As the name implies, the longitudinal approach studies
development over time and is the most direct way to watch it occur. More important,
it is the only way to answer certain questions about the stability or instability of behavior: Will characteristics such as aggression, dependency, or mistrust observed in
infancy or early childhood persist into adulthood? Will a regular exercise program begun in middle age have benefits in later life? Does people’s satisfaction with their lives
remain the same or change across adulthood? Such questions can be explored only by
testing people at one point in their development and then retesting them later.
The Spotlight on Research feature focuses on the last question about life satisfaction. As you read it, pay close attention to the questions and how the researchers approached them. Doing so will give you insight into the creative process of research and
into the potential strengths and weaknesses of a research study.
Usually the repeated testing of longitudinal studies extends over years, but not
always. In a microgenetic study, a special type of longitudinal design, participants
are tested repeatedly over a span of days or weeks, typically with the aim of observing
change directly as it occurs. For example, researchers might test children every week,
starting when they are 12 months old and continuing until 18 months. Microgenetic
studies are particularly useful when investigators have hypotheses about a specific
period when developmental change should occur (Flynn, Pine, & Lewis, 2006). In this
case, researchers arrange to test individuals frequently before, during, and after this
period, hoping to see change as it happens (e.g., Opfer & Siegler, 2004).
Microgenetic studies are particularly useful in tracking change as a result of intervention. For example, older adults could be given a series of measures of memory ability and interviewed about their use of memory strategies. A series of training sessions
about how to improve memory could be introduced, including additional memory
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Spotlight on Research
Stability and Change in Life Satisfaction
life satisfaction ratings over the course of the
study. The stability of life satisfaction was lower
than that for personality traits. Stabilities were
highest for height, weight, and body mass index.
What did the investigators conclude? Fujita and
Diener argued that life satisfaction is somewhat
stable but can vary over time. This is important,
particularly for people whose life satisfaction
may be low; there is the chance that things could
improve.
What converging evidence would strengthen
these conclusions? Because the sample included
only German adults, it would be necessary to
study people from other cultures to find out
whether the results generalize cross-culturally.
To enhance your understanding of this
research, go to www.cengage.com/
psychology/kail to complete critical thinking
questions and explore related websites.
❚ Figure 1.7
Note that overall life satisfaction showed some decrease over a 17-year period compared to height, weight, body mass index, and personality, but was less stable over
time than personality.
1.0
0.8
Correlation coefficient
Who were the investigators and what was the
aim of the study? Frank
Fujita and Ed Diener (2005) were interested in
learning whether life satisfaction stays the same
or changes across adulthood. So they compared
measures of life satisfaction to physiological and
demographic data over a 17-year period.
How did the investigators measure the topic
of interest? Life satisfaction was measured by
self-ratings to the question “How happy are you
at present with your life as a whole?” from
0 (totally unhappy) to 10 (totally happy). Monthly
household income was also obtained through
self-report. Additionally, measures of height,
weight, body mass index, systolic and diastolic
blood pressure, and personality traits were
obtained.
Who were the participants in the study? The
participants were 3,608 Germans (1,709 males
and 1,899 females) who had answered a question about life satisfaction every year from 1984
to 2000 as part of the German Socio-Economic
Panel study. The sample is a nationally representative sample of German adults born between
1902 and 1968.
What was the design of the study? The study
used a longitudinal design, with assessments conducted annually.
Were there ethical concerns with the study? All
of the participants were provided information
about the purpose of the study and the tests
they would take. Each participant provided informed consent.
What were the results? As you can see in
❚ Figure 1.7, there was modest stability in adults’
life satisfaction from year to year, but there is an
overall decrease as the time between comparison periods increases over the 17 years. Roughly
25% of the sample changed significantly in their
0.6
0.4
Inches
Pounds
BMI
Systolic
0.2
0.0
1
Diastolic
Trait
Income
LS
6
11
16
Years
From Fujita, F., & Diener, E. (2005). Life satisfaction set point stability and change.
Journal of Personality and Social Psychology, 88(1), p. 161. Copyright © 2005 by the
American Psychological Association.
tests and interviews, followed by a posttest to find out how much the participants’
skills improved after being trained. The microgenetic method would look in detail at
the performance of those who learned and improved after training compared to those
who did not and then search for differences in either the pattern of performance in
the memory tests or in the details in the interviews for reasons why some people improved whereas others did not. This would provide a vivid portrait of change over the
period of the intervention.
The longitudinal approach, however, has disadvantages that frequently offset its
strengths. One is cost: The expense of keeping up with a large sample of individuals can be staggering. A related problem is the constancy of the sample over the
course of the research. Maintaining contact with people over several years (or several
decades) can be a challenge. And even among those who do not move away, some lose
interest and choose not to continue. These “dropouts” are often significantly different
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from their peers, and this fact may also distort the outcome. For example, a group of
older adults may seem to show intellectual stability late in life. What may have happened, however, is that those who found earlier testing most difficult quit the study
and thereby raised the group average on the next round.
Even when the sample remains constant, taking the same test many times may
make people “test-wise.” Improvement over time may be attributed to development
when it actually stems from practice with a particular test. Changing the test from
year to year solves the practice problem but raises the question of how to compare
responses to different tests. Because of this and other problems with the longitudinal
method, human development researchers often use cross-sectional studies instead.
Cross-Sectional Studies
cross-sectional study
study in which developmental differences
are identified by testing people of different ages
cohort effects
problem with cross-sectional designs in
which differences between age groups
(cohorts) may result as easily from environmental events as from developmental
processes
In a cross-sectional study, developmental differences are identified by testing people of
different ages in the study. Development is charted by noting the differences between
individuals of different ages at the same point in calendar time. The cross-sectional
approach avoids almost all the problems associated with repeated testing; it avoids
costly record keeping and sample loss as well. But cross-sectional research has its own
weaknesses. Because people are tested at only one point in their development, we learn
nothing about the continuity of development. Consequently, we cannot tell whether
an aggressive 14-year-old remains aggressive at age 30 because the person would be
tested at age 14 or age 30 but not at both ages.
Cross-sectional studies are also affected by cohort effects, meaning that differences between age groups (cohorts) may result as much from environmental events as
from developmental processes. In a simple cross-sectional study, we typically compare
people from two age groups. Differences that we find are attributed to the difference in
age, but this needn’t be the case. Why? The cross-sectional study assumes that, when
the older people were younger, they resembled the people in the younger age group.
This isn’t always true, and this fact—rather than difference in age—may be responsible for differences between the groups. Suppose that young adults were found to
be more imaginative than middle-aged adults. Should we conclude that imagination
declines between these ages? Not necessarily. Perhaps a new curriculum to nourish
creativity was introduced after the middle-aged adults completed school. Because the
younger adults experienced the curriculum but the middle-aged adults did not, the
difference between them is difficult to interpret.
When the two general research designs shown in ● Table 1.5 are combined with the
two designs that are unique to development, four prototypic designs are possible: crosssectional correlational studies, cross-sectional experimental studies, longitudinal correlational studies, and longitudinal experimental studies. You’ll read about each of these
designs in this book, although the two cross-sectional designs occur more frequently
than the two longitudinal designs. Why? For most developmentalists, the relative ease
of conducting cross-sectional studies more than compensates for their limitations.
Sequential Studies
sequential design
developmental research design based on
cross-sectional and longitudinal designs
Some researchers use another, more complex research approach, called a sequential
design, that is based on both cross-sectional and longitudinal designs. Basically, a sequential design begins with a simple cross-sectional or longitudinal design. At some
regular interval, the researcher then adds more cross-sectional or longitudinal studies,
resulting in a sequence of these studies. For example, suppose a researcher wants to
learn whether adults’ memory ability changes with age. One way to do this would be to
follow several groups of people of different ages over time, creating a sequence of longitudinal studies. The start would be a typical cross-sectional study in which 60- and
75-year-olds are tested. Then the two groups would be retested every 3 years, creating
two separate longitudinal studies.
Although sequential designs are relatively rare because they are so expensive, they
have several advantages. Most important, they help address most of the limitations
described earlier concerning single cross-sectional and longitudinal studies. For example, sequential designs help isolate cohort effects and also help determine whether
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● TABLE 1.5
Designs Used in Human Development Research
Type of Design
General Designs
Correlational
Experimental
Developmental
Designs
Longitudinal
Cross-sectional
Sequential
Definition
Strengths
Weaknesses
Observe variables as they
exist in the world and determine their relations
Manipulate independent
variable and determine effect
on dependent variable
Behavior is measured as it
occurs naturally
Cannot determine cause and
effect
Control of variables allows conclusions about cause and effect
Work is often laboratory-based,
which can be artificial
One group of people is
tested repeatedly as they
develop
People of different ages are
tested at the same time
Only way to chart an individual’s
development and look at the
stability of behavior over time
Convenient—solves all problems associated with longitudinal studies
Multiple groups of people
are tested over time, based
on either multiple longitudinal or cross-sectional designs
Best way to address limitation
of single longitudinal and crosssectional designs
Expensive, participants drop
out, and repeated testing can
distort performance
Cannot study stability of behavior; cohort effects complicate
interpretation of differences between
groups
Very expensive and time consuming; may not completely
solve limitations of longitudinal
and cross-sectional designs
age-related changes are due to participant dropout or to some other cause. We will
encounter examples of sequential designs when we consider some of the large studies
examining the normal processes of aging in Chapter 14.
| Integrating Findings From Different Studies
Several times in the past few pages, we’ve emphasized the value of using different
methods to study the same phenomenon. The advantage of this approach is that conclusions are most convincing when the results are the same regardless of method.
In reality, though, findings are often inconsistent. For example, suppose many researchers find that people often share personal information with friends (on MySpace
or Facebook, for instance), some researchers find that people share occasionally with
friends, and a few researchers find that people never share with friends. What results
should we believe? What should we conclude? Meta-analysis allows researchers to
synthesize the results of many studies to estimate relations between variables (Becker,
2003). In conducting a meta-analysis, investigators find all studies published on a topic
over a substantial period of time (e.g., 10 to 20 years) and then record and analyze the
results and important methodological variables.
The usefulness of meta-analysis is illustrated in a study by McClure (2000), who
asked whether boys and girls differ in their ability to recognize emotions in facial
expressions. She found 60 studies, published between 1931 and 1999, that included
nearly 10,000 children and adults. In each study, participants were administered some
sort of task, like the one shown in Figure 1.3 in which the aim is to select a face expressing a particular emotion. Analyzing across the results of all 60 studies, McClure
found that, overall, girls recognized emotions in facial expressions more accurately
than boys. The gender difference was constant from 4 to 16 years of age and was the
same when the faces were shown as photos and as drawings. However, the gender
difference was larger when participants judged emotions in children’s faces than when
they judged emotions in adults’ faces.
Thus, meta-analysis is a particularly powerful tool because it allows scientists
to determine whether a finding generalizes across many studies that used different
meta-analysis
a tool that enables researchers to synthesize the results of many studies to
estimate relations between variables
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methods. In addition, meta-analysis can reveal the impact of those different methods
on results.
| Conducting Research Ethically
© Amy C. Etra / PhotoEdit
Choosing a good research design involves more than just selecting a particular method.
Researchers must determine whether the methods they plan on using are ethical. That
is, when designing a research study, investigators must do so in a way
that does not violate the rights of people who participate. To verify
that every research project incorporates these protections, local panels of experts and community representatives review proposed studies before any data are collected. Only with the approval of this panel
can scientists begin their study. If the review panel objects to some
aspects of the proposed study, then the researcher must revise those
aspects and present them anew for the panel’s approval. Likewise,
each time a component of a study is changed, the review panel must
be informed and give its approval.
To guide review panels, professional organizations (e.g., the American Psychological Association) and government agencies (e.g., the
National Institutes of Health) have codes of conduct that specify the
rights of research participants as well as procedures to protect these
participants. The following essential guidelines are included in all of
these codes.
Minimize risks to research participants. Use methods that have
the least potential for causing harm or stress for research participants. During the research, monitor the procedures to
ensure avoidance of any unforeseen stress or harm.
Describe the research to potential participants so they can determine whether
they wish to participate. Prospective participants must be told the purpose
of the project, what they will be asked to do, whether there are any risks or
potential harm or any benefits they may receive, that they are free to discontinue participation at any time without penalty, that they are entitled to a
complete debriefing at the end of the project, and any other relevant information the review panel deems appropriate. After the study has been explained,
each participant signs a document that states he or she understands what they
will do in the study. Special caution must be exercised in obtaining consent
for the participation of children and adolescents, as well as people who
have conditions that affect intellectual functioning (e.g., Alzheimer’s disease,
severe head injury). In these cases, consent from a parent, legal guardian,
or other responsible person—in addition to consent of the participant—is
necessary.
Avoid deception; if participants must be deceived, provide a thorough explanation of the true nature of the experiment as soon as possible. Providing
complete information about a study in advance sometimes biases or distorts a
person’s responses. Consequently, investigators may provide participants with
partial information about the study or even mislead them about its true purpose. As soon as it is feasible—typically, just after the experiment—any false
information that was given to research participants must be corrected, and the
reasons for the deception must be provided.
Results should be anonymous or confidential. Research results should be anonymous, which means that people’s data cannot be linked to their name. When
anonymity is not possible, research results should be confidential, which
means that the identity of participants is known only to the investigator(s)
conducting the study.
■
Informed consent is a necessary aspect of any
research effort in human development.
■
■
■
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Conducting research ethically is an obligation of every investigator. If you conduct
a project, even in connection with a course, you should submit your procedures for
review. If you are a participant in someone else’s project, make sure you are given appropriate and complete information and read it thoroughly.
| Communicating Research Results
When the study is complete and the data analyzed, researchers write a report of their
work that describes what the researchers did and why, their results, and the meaning(s)
behind their results. The researchers will submit the report to one of several scientific journals that specialize in human development research. Some of these are Child
Development, Developmental Psychology, Psychology and Aging, and the Journals of
Gerontology. If the journal editor accepts the report then it will appear in the journal,
where other human development researchers can learn of the results.
These reports of research are the basis for virtually all the information we present
in this book. You have already encountered many citations of research in the format
of names in parentheses, followed by a date, like this:
(Alexander & Bowen, 2004)
This indicates the person(s) who did the research and the year in which it was published. By looking in the Reference section at the end of the book, which is organized
alphabetically by the first author’s last name, you can find the title of the article and
the journal where it was published.
All of these different steps in research may seem tedious and involved to you.
For a human development researcher, however, much of the fun of doing research is
planning a study that no one has done before and that will provide useful information
to other specialists. This is one of the most creative and challenging parts of human
development research.
| Applying Research Results: Social Policy
One question many people have about research is whether any of it really matters. Actually, research on human development has a strong influence on policy makers and
politicians. For example, every state in the United States and many countries around
the world have laws against child abuse and law that govern child labor practices.
Many countries have laws setting minimum ages for certain activities, such as consuming alcohol. Some states in the United States are changing the way older drivers
are screened when they renew their driver’s licenses.
These and many other examples demonstrate that the research done by developmentalists influences many aspects of daily life that are governed by laws and societal
rules. Much of the debate over Social Security and Medicare (in the U.S. presidential
campaigns of 2000 and 2004), and over President George W. Bush’s plans to reform
Social Security, hinged on different interpretations of data about older adults.
At several points in the text, we will describe some of the most important connections between human development research and social policy. As you will see, these
connections are broad ranging and include areas that you may even take for granted.
For example, lead-based paint can no longer be used in the United States, mainly
because research by developmentalists showed that infants and young children who
were exposed to lead-based paint (and who sometimes ate paint chips as they flaked
off) suffered brain damage and learning problems. Research on human development
not only provides many insights into what makes people tick but can also provide
ways to improve the quality of life.
However, the views of scientists, ethicists, public citizens, and government sometimes collide in ways that result in significant debate concerning research. Such is the
case with stem cell research, a hotly debated topic explored in the Current Controversies feature.
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Current Controversies
Stem Cell Research
Imagine you were unable
to walk because of a
severe spinal cord injury
received in an accident. Imagine further that
there was a possible cure: inducing the damaged
nerve cells in your spine to regenerate, thereby
enabling you to walk again. Would you support
every effort possible to ensure that this research
was pursued, especially if you knew that there
were positive outcomes in research (see Nistor
et al., 2005) on other animal species? But what
if you knew also that applying this research to
humans would require using stem cells from human embryos? Would that affect your opinion
about the research?
Research on regeneration of nerve cells and
for treatment of other diseases—such as Alzheimer’s disease, leukemia, and Parkinson’s
disease—could be revolutionized through the
use of stem cells. Researchers such as Dr. Hans
Keirstead believe that stem cell research represents the future for medical treatment breakthroughs. Stem cells are unspecialized human or
animal cells that can produce mature specialized
body cells and at the same time replicate themselves. Embryonic stem cells are derived from a
blastocyst, which is a very young embryo that
contains 200 to 250 cells and is shaped like a
hollow sphere (see Chapter 2 for more information). The stem cells themselves are the cells
in the blastocyst that ultimately would develop
into a person or animal. “Adult” stem cells are
derived from the umbilical cord and placenta or
from blood, bone marrow, skin, and other tissues. Germ line cells, similar to stem cells, come
from a fetus that is 5 to 9 weeks old and are
derived from tissue that would have developed
into the ovaries or testes.
Medical researchers are interested in using
stem cells to repair or replace damaged body
tissues because stem cells are less likely than
other foreign cells to be rejected by the immune system when they are implanted in the
body. Embryonic stem cells have the capacity
to develop into every type of tissue found in an
adult. Stem cells have been used experimentally
to form the blood-making cells of the bone marrow and heart, blood vessel, muscle, and insulinproducing tissue. Embryonic germ line cells have
been used to help paralyzed mice regain some of
their ability to move. Since the 1990s, umbilical
cord blood stem cells have been used to treat
heart and other defects in children who have
rare metabolic diseases and to treat children
with certain anemias and leukemias. The blood
stem cells can migrate to damaged tissues and
repair them.
Even though stem cell research holds much
promise and has already been shown to be
effective in treating some conditions, it is extremely controversial. The Bush administration
has restricted federally funded research to cer-
tain existing colonies of stem cells, pointing out
that creating additional such cells involves the
destruction of human embryos. But proponents
of the research claim that some of the existing
colonies may be contaminated. They also argue
that early embryos have no feeling or consciousness and that most of them used in research are
left over from fertility clinics and are destined
to be discarded anyway. For more information
about stem cell research and the official U.S.
Government position, check the websites at the
National Institutes of Health (http://stemcells
.nih.gov/) and the American Association for the
Advancement of Science (http://www.aaas.org/
spp/cstc/briefs/stemcells/).
At this point, many states are making their
own decisions about whether to support stem
cell research. For example, voters in California
passed Proposition 71 in 2004, which resulted in
$3 billion in state funding for stem cell research
and established a 29-member stem cell research
review board. New Jersey, Ohio, and
Connecticut also provide state funding for stem
cell research. Other states (Massachusetts,
Virginia, Indiana) have either created centers
without funding or are considering using state
funds. One thing is certain, though: The debate
on whether to provide public funding (federal
or state) for stem cell research will continue for
many years to come.
Test Yourself
5. Human development researchers must submit their plans
for research to a review board that determines whether the
research
.
INTERPRET
How could a longitudinal design be used to test Piaget’s
theory?
APPLY
While at work, you notice that some people advance faster in
their careers than others. How could you determine what factors might be responsible for or related to such success?
Recall answers: (1) naturalistic observation, (2) sample, (3) dependent, (4) influence of
repeated testing on a person’s performance, (5) preserves the rights of research participants
RECALL
1. In
, people are
observed as they behave spontaneously
in a real-life setting.
2. A
is a group of individuals thought
to be representative of some larger population of interest.
3. The
variable is measured in an
experiment to evaluate the impact of the variable that was
manipulated.
4. Problems of longitudinal studies include the length of time
to complete the work, loss of research participants over
time, and
.
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Problems With Using Photographs to Measure
Understanding of Emotions
On page 23, we invited you to consider why asking children to judge emotions from
photos may not be valid. Children’s judgments of the emotions depicted in photographs may be less accurate than they would be in real life because, in real life:
(1) facial features are usually moving—not still as in the photographs—and movement may be one of the clues children naturally use to judge emotions; (2) facial
expressions are often accompanied by sounds, and children use both sight and
sound to judge emotions; and (3) children most often judge facial expressions of
people they know (parents, siblings, peers, teachers), and knowing the “usual” appearance of a face may help children judge emotions accurately.
SU M M A RY
1.1 Thinking About Development
What fundamental issues of development have scholars addressed throughout history?
■ Three main issues are prominent in the study of human
development. The nature–nurture issue involves the degree to which genetics and the environment influence
human development. In general, theorists and researchers view nature and nurture as mutually interactive
influences; development is always shaped by both. The
continuity–discontinuity issue concerns whether the
same explanations (continuity) or different explanations
(discontinuity) must be used to explain changes in people
over time. Continuity approaches emphasize quantitative
change; discontinuity approaches emphasize qualitative
change. In the issue of universal versus context-specific
development, the question is whether development follows the same general path in all people or is fundamentally dependent on the sociocultural context.
What are the basic forces in the biopsychosocial framework?
How does the timing of these forces make a difference in their
impact?
■ Development is based on the combined impact of four
primary forces. Biological forces include all genetic and
health-related factors that affect development. Many of
these biological forces are determined by our genetic
code.
■ Psychological forces include all internal cognitive, emotional, perceptual, and personality factors that influence
development. Collectively, psychological forces explain
the most noticeable differences in people.
■ Sociocultural forces include interpersonal, societal, cultural, and ethnic factors that affect development. Culture
consists of the knowledge, attitudes, and behavior associated with a group of people. Overall, sociocultural forces
provide the context or backdrop for development.
■ Life-cycle forces provide a context for understanding how
people perceive their current situation and its effects on
them.
■ The biopsychosocial framework emphasizes that the four
forces are mutually interactive; development cannot be
understood by examining the forces in isolation. Furthermore, the same event can have different effects, depending on when it happens.
1.2 Developmental Theories
What is a developmental theory?
■ Developmental theories organize knowledge so as to provide testable explanations of human behaviors and the
ways in which they change over time. Current approaches
to developmental theory focus on specific aspects of behavior. At present, there is no single unified theory of human development.
How do psychodynamic theories account for development?
■ Psychodynamic theories propose that behavior is determined by the way people deal with conflicts they face
at different ages. Erikson proposed a life-span theory of
psychosocial development, consisting of eight universal
stages, each characterized by a particular struggle.
What is the focus of learning theories of development?
■ Learning theory focuses on the development of observable behavior. Operant conditioning is based on the notions of reinforcement, punishment, and environmental
control of behavior. Social learning theory proposes that
people learn by observing others.
How do cognitive-developmental theories explain changes in
thinking?
■ Cognitive-developmental theory focuses on thought processes. Piaget proposed a four-stage universal sequence
based on the notion that, throughout development,
people create their own theories to explain how the
world works. According to information-processing theory,
people deal with information like a computer does; development consists of increased efficiency in handling information. Vygotsky emphasized the influence of culture on
development.
What are the main points in the ecological and systems
approach?
■ Bronfenbrenner proposed that development occurs in the
context of several interconnected systems of increasing
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complexity. The competence–environmental press theory
postulates that there is a “best fit” between a person’s
abilities and the demands placed on that person by the
environment.
What are the major tenets of life-span and life course theories?
■ According to the life-span perspective, human development is characterized by multidirectionality, plasticity,
historical context, and multiple causation. All four developmental forces are critical.
■ Selective optimization with compensation refers to the
developmental trends to focus one’s efforts and abilities
in successively fewer domains as one ages and to acquire
ways to compensate for normative losses.
■ The life course perspective refers to understanding human development within the context of the historical
time period in which a generation develops, which creates unique sets of experiences.
1.3 Doing Developmental Research
How do scientists measure topics of interest in studying human
development?
■ Research typically begins by determining how to measure
the topic of interest. Systematic observation involves
recording people’s behavior as it takes place, in either
a natural environment (naturalistic observation) or a
structured setting (structured observation). Researchers
sometimes create tasks to obtain samples of behavior. In
self reports, people answer questions posed by the experimenter. Physiological measures provide a way to examine
body-behavior relationships.
■ Researchers must determine that their measures are reliable and valid; they must also obtain a sample representative of some larger population.
What research designs are used to study human development?
■ In correlational studies, investigators examine relations
among variables as they occur naturally. This relation is
often measured by a correlation coefficient, which can
vary from −1 (strong inverse relation) to 0 (no relation) to
+1 (strong positive relation). Correlational studies cannot
determine cause and effect, so researchers do experimental studies in which an independent variable is manipulated and the impact of this manipulation on a dependent
variable is recorded. Experimental studies allow conclusions about cause and effect, but the required strict control of other variables often makes the situation artificial.
The best approach is to use both experimental and correlational studies to provide converging evidence. Qualitative
research permits more in-depth analysis of behavior and
is often used as a preliminary step for, or in conjunction
with, quantitative research.
■ To study development, some researchers use a longitudinal design in which the same people are observed repeatedly as they grow. Microgenetic methods use multiple,
detailed observations of behavior during the period in
which developmental change occurs. These approaches
provide evidence concerning actual patterns of individual
growth but have several shortcomings as well: They are
time consuming, some people drop out of the project, and
repeated testing can affect performance.
■ An alternative, the cross-sectional design, involves testing
people of different ages. This design avoids the problems
of the longitudinal design but provides no information
about individual growth. Also, what appear to be age differences may be cohort effects. Because neither design is
problem-free, the best approach involves using both to
provide converging evidence.
■ Sequential designs are based on multiple longitudinal or
cross-sectional designs.
How do researchers integrate results from multiple studies?
■ Meta-analysis provides a way for researchers to look for
trends across multiple studies to estimate the relations
among variables.
What ethical procedures must researchers follow?
■ Planning research also involves selecting methods that
preserve the rights of research participants. Experimenters must minimize the risks to participants, describe
the research so that candidates can make an informed
decision about participating, avoid deception, and keep
results anonymous or confidential.
How do investigators communicate results from research
studies?
■ Once research data are collected and analyzed, investigators publish the results in scientific outlets such as
journals and books. Such results form the foundation of
knowledge about human development.
How does research affect public policy?
■ Research results are sometimes used to inform and shape
public policy. Controversial topics such as stem cell research also form the basis for public policy in terms of
what types of research are permitted.
K E Y TE RM S
human development (4)
nature–nurture issue (4)
continuity–discontinuity issue (5)
universal versus context-specific
development issue (5)
biological forces (6)
psychological forces (6)
sociocultural forces (6)
life-cycle forces (6)
biopsychosocial framework (6)
theory (11)
psychodynamic theories (11)
psychosocial theory (11)
epigenetic principle (12)
operant conditioning (12)
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reinforcement (12)
punishment (12)
imitation (observational learning) (12)
self-efficacy (13)
information-processing theory (14)
ecological theory (15)
microsystem (16)
mesosystem (16)
exosystem (16)
macrosystem (16)
life-span perspective (17)
selective optimization with
compensation (SOC) model (18)
life-course perspective (19)
systematic observation (22)
naturalistic observation (22)
structured observations (22)
self-reports (23)
reliability (24)
validity (24)
populations (25)
sample (25)
correlational study (25)
correlation coefficient (25)
experiment (26)
independent variable (26)
dependent variable (26)
qualitative research (28)
longitudinal study (28)
microgenetic methods (28)
cross-sectional study (30)
cohort effects (30)
sequential design (30)
meta-analysis (31)
stem cells (34)
L EA RN M O R E A B O U T IT
Websites
Readings
Visit the Human Development companion website for
all URLs.
■ The Human Development Book Companion Website
See the companion website www.cengage.com/psychology/kail for practice quiz questions, Internet exercises,
glossary, flashcards, and more.
■ American Psychological Association
The American Psychological Association and the Association for Psychological Science have numerous sources
of information for researchers and consumers on their
websites.
■ National Institutes of Health
The Office of Human Subjects Research at the National
Institutes of Health publishes the Guidelines for the Conduct of Research Involving Human Subjects. These guidelines govern all researchers who use human subjects.
BALTES, P. B. (1987). Theoretical propositions of lifespan developmental psychology: On the dynamics between growth
and decline. Developmental Psychology, 23, 611–626. One of
the true classics in human development, this is an excellent
overview of what it means to take a holistic view of life-span
development. Written by one of the leading proponents of
this approach, the article is moderately difficult reading.
BALTES, P. B., REESE, H. W., & NESSELROADE, J. R.
(1977). Life-span developmental psychology: Introduction to
research methods. Pacific Grove, CA: Brooks/Cole. This is one
of the classic texts on developmental research methods and
still one of the best. It’s very readable and has an easily understood presentation of research designs and methods.
DELANY, S., & DELANY, E. (1993). Having our say. New
York: Kodansha International. This is the life story of Sadie
and Bessie Delany, who are described in the text. Their lives
are an excellent example of life-course theory. This book was
adapted for a popular play.
GARDINER, H. W., & KOSMITZKI, C. (2008). Lives across
cultures: Cross-cultural human development (4th ed.). Boston: Allyn & Bacon. A readable introduction to how human
development occurs in various world cultures. This book
pulls together much of the available research.
McLOYD, V. C. (2004). Linking race and ethnicity to culture:
Steps along the road from inference to hypothesis testing.
Human Development, 47, 185–191. A thorough but high-level
discussion of the complexities and dynamics of culture from
a theoretical perspective.
NEWMAN, B. M., & NEWMAN, P. R. (2007). Theories of human development. Mahwah, NJ: Erlbaum. A good overview
of the various theories of human development.
Go to www.cengage.com/login to link to CengageNOW, your
online study tool. First take the Pre-Test for this chapter to
get your Personalized Study Plan, which will identify topics
you need to review and direct you to online resources. Then
take the Post-Test to determine what concepts you have mastered and what you still need work on.
THE STUDY OF HUMAN DEVELOPMENT
Copyright 2010 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.
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Copyright 2010 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.