Lecture Notes for HDEV: Human Lifespan Development, 6th Edition
Lecture Notes for HDEV: Human Lifespan Development, 6th Edition summarizes important topics for quick revision.
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Chapter 1
H i s t o r y , T h e o r i e s , a n d M e t h o d s
Chapter Overview
This chapter provides the general introduction to the field of developmental psychology. It
begins with a definition of child development and a discussion of the purposes and goals of
theory and research in the field of developmental psychology. A brief survey of the pioneers in
the field of developmental psychology, including John Locke, Jean-Jacques Rousseau, G.
Stanley Hall, Alfred Binet, William Perry, and Gisella Labouvie-Vief, is followed by a
description and evaluation of each of the major perspectives on child development—
psychoanalytic, learning (behavioral and social cognitive theories), cognitive, biological,
ecological, and sociocultural. Next, the nature-nurture, continuity-discontinuity, and active–
passive controversies in the field of development are overviewed. Finally, research methods are
described (naturalistic-observation, case study, correlation, experimental research, longitudinal
research, cross-sectional studies, and cross-sequential research), including a presentation of the
general idea behind the scientific method, ways of gathering information in child developmental
science, the correlational method (and its limitations), and how to approach and design
experiments. The chapter ends with an overview of the special methods needed to assess
development over time, specifically longitudinal versus cross-sectional research and the ways in
which the cross-sequential research design handles the advantages and disadvantages of each, as
well as a discussion of the ethical issues in research with children.
Chapter Learning Objectives
Having read the chapter, students should be able to achieve the objectives given below.
• Explain what child development is
• Describe why it is important to study child development
• Discuss the history of child development
• Compare the different developmental views across time
• Compare the different major theories of child development
• Analyze the major controversies in the study of child development
• Identify and compare different research methods used in the study of child development
• Explain the purpose of each of the different research methods discussed in this chapter
• Describe the different ethical considerations when conducting developmental research
Chapter Outline
Chapter 1
H i s t o r y , T h e o r i e s , a n d M e t h o d s
Chapter Overview
This chapter provides the general introduction to the field of developmental psychology. It
begins with a definition of child development and a discussion of the purposes and goals of
theory and research in the field of developmental psychology. A brief survey of the pioneers in
the field of developmental psychology, including John Locke, Jean-Jacques Rousseau, G.
Stanley Hall, Alfred Binet, William Perry, and Gisella Labouvie-Vief, is followed by a
description and evaluation of each of the major perspectives on child development—
psychoanalytic, learning (behavioral and social cognitive theories), cognitive, biological,
ecological, and sociocultural. Next, the nature-nurture, continuity-discontinuity, and active–
passive controversies in the field of development are overviewed. Finally, research methods are
described (naturalistic-observation, case study, correlation, experimental research, longitudinal
research, cross-sectional studies, and cross-sequential research), including a presentation of the
general idea behind the scientific method, ways of gathering information in child developmental
science, the correlational method (and its limitations), and how to approach and design
experiments. The chapter ends with an overview of the special methods needed to assess
development over time, specifically longitudinal versus cross-sectional research and the ways in
which the cross-sequential research design handles the advantages and disadvantages of each, as
well as a discussion of the ethical issues in research with children.
Chapter Learning Objectives
Having read the chapter, students should be able to achieve the objectives given below.
• Explain what child development is
• Describe why it is important to study child development
• Discuss the history of child development
• Compare the different developmental views across time
• Compare the different major theories of child development
• Analyze the major controversies in the study of child development
• Identify and compare different research methods used in the study of child development
• Explain the purpose of each of the different research methods discussed in this chapter
• Describe the different ethical considerations when conducting developmental research
Chapter Outline
1
Chapter 1
H i s t o r y , T h e o r i e s , a n d M e t h o d s
Chapter Overview
This chapter provides the general introduction to the field of developmental psychology. It
begins with a definition of child development and a discussion of the purposes and goals of
theory and research in the field of developmental psychology. A brief survey of the pioneers in
the field of developmental psychology, including John Locke, Jean-Jacques Rousseau, G.
Stanley Hall, Alfred Binet, William Perry, and Gisella Labouvie-Vief, is followed by a
description and evaluation of each of the major perspectives on child development—
psychoanalytic, learning (behavioral and social cognitive theories), cognitive, biological,
ecological, and sociocultural. Next, the nature-nurture, continuity-discontinuity, and active–
passive controversies in the field of development are overviewed. Finally, research methods are
described (naturalistic-observation, case study, correlation, experimental research, longitudinal
research, cross-sectional studies, and cross-sequential research), including a presentation of the
general idea behind the scientific method, ways of gathering information in child developmental
science, the correlational method (and its limitations), and how to approach and design
experiments. The chapter ends with an overview of the special methods needed to assess
development over time, specifically longitudinal versus cross-sectional research and the ways in
which the cross-sequential research design handles the advantages and disadvantages of each, as
well as a discussion of the ethical issues in research with children.
Chapter Learning Objectives
Having read the chapter, students should be able to achieve the objectives given below.
• Explain what child development is
• Describe why it is important to study child development
• Discuss the history of child development
• Compare the different developmental views across time
• Compare the different major theories of child development
• Analyze the major controversies in the study of child development
• Identify and compare different research methods used in the study of child development
• Explain the purpose of each of the different research methods discussed in this chapter
• Describe the different ethical considerations when conducting developmental research
Chapter Outline
Chapter 1
H i s t o r y , T h e o r i e s , a n d M e t h o d s
Chapter Overview
This chapter provides the general introduction to the field of developmental psychology. It
begins with a definition of child development and a discussion of the purposes and goals of
theory and research in the field of developmental psychology. A brief survey of the pioneers in
the field of developmental psychology, including John Locke, Jean-Jacques Rousseau, G.
Stanley Hall, Alfred Binet, William Perry, and Gisella Labouvie-Vief, is followed by a
description and evaluation of each of the major perspectives on child development—
psychoanalytic, learning (behavioral and social cognitive theories), cognitive, biological,
ecological, and sociocultural. Next, the nature-nurture, continuity-discontinuity, and active–
passive controversies in the field of development are overviewed. Finally, research methods are
described (naturalistic-observation, case study, correlation, experimental research, longitudinal
research, cross-sectional studies, and cross-sequential research), including a presentation of the
general idea behind the scientific method, ways of gathering information in child developmental
science, the correlational method (and its limitations), and how to approach and design
experiments. The chapter ends with an overview of the special methods needed to assess
development over time, specifically longitudinal versus cross-sectional research and the ways in
which the cross-sequential research design handles the advantages and disadvantages of each, as
well as a discussion of the ethical issues in research with children.
Chapter Learning Objectives
Having read the chapter, students should be able to achieve the objectives given below.
• Explain what child development is
• Describe why it is important to study child development
• Discuss the history of child development
• Compare the different developmental views across time
• Compare the different major theories of child development
• Analyze the major controversies in the study of child development
• Identify and compare different research methods used in the study of child development
• Explain the purpose of each of the different research methods discussed in this chapter
• Describe the different ethical considerations when conducting developmental research
Chapter Outline
2
I. The Development of the Study of Human Development
• Developmental psychology is the discipline that studies the physical, cognitive, social,
and emotional development of humans.
• In ancient times and in the Middle Ages, children often were viewed as innately evil and
discipline was harsh.
• English philosopher John Locke (1632-1704) believed that the child came into the world as
a tabula rasa—a “blank tablet” or clean slate—that was written on by experience.
• Jean-Jacques Rousseau (1712-1778), a Swiss-French philosopher, argued that children are
inherently good and that, if allowed to express their natural impulses, they will develop
into generous and moral individuals.
• G. Stanley Hall (1844-1924) is credited with founding child development as an academic
discipline and bringing scientific attention to focus on the period of adolescence.
• French psychologist Alfred Binet (1857-1911), along with Theodore Simon (1872-1961),
developed the first standardized intelligence test near the beginning of the 20th century.
• In the 20th century, psychologists began to take on a life-span perspective, in which they
viewed human development as occurring throughout the individual’s lifetime.
o William Perry and Gisella Labouvie-Vief, for example, have studied the
development of cognitive complexity from adolescence to late adulthood.
o K. W. Schaie and others have studied trends in various mental abilities throughout
middle and late adulthood, showing that some abilities decline in middle and late
adulthood, but others that represent the accumulation of decades of knowledge can
advance into late adulthood.
II. Theories of Development
• John B. Watson (1878-1958), the founder of American behaviorism, viewed development
in terms of learning theory.
o He generally agreed with John Locke that children’s ideas, preferences, and skills are
shaped by experience.
• Arnold Gesell expressed the opposing idea that biological maturation—the unfolding of
genetically determined traits, structures, and functions—was the main principal of
development.
A. The Psychoanalytic Perspective
• A number of theories fall within the psychoanalytic perspective.
o Each owes its origin to Sigmund Freud and views children—and adults—as
caught in conflict.
I. The Development of the Study of Human Development
• Developmental psychology is the discipline that studies the physical, cognitive, social,
and emotional development of humans.
• In ancient times and in the Middle Ages, children often were viewed as innately evil and
discipline was harsh.
• English philosopher John Locke (1632-1704) believed that the child came into the world as
a tabula rasa—a “blank tablet” or clean slate—that was written on by experience.
• Jean-Jacques Rousseau (1712-1778), a Swiss-French philosopher, argued that children are
inherently good and that, if allowed to express their natural impulses, they will develop
into generous and moral individuals.
• G. Stanley Hall (1844-1924) is credited with founding child development as an academic
discipline and bringing scientific attention to focus on the period of adolescence.
• French psychologist Alfred Binet (1857-1911), along with Theodore Simon (1872-1961),
developed the first standardized intelligence test near the beginning of the 20th century.
• In the 20th century, psychologists began to take on a life-span perspective, in which they
viewed human development as occurring throughout the individual’s lifetime.
o William Perry and Gisella Labouvie-Vief, for example, have studied the
development of cognitive complexity from adolescence to late adulthood.
o K. W. Schaie and others have studied trends in various mental abilities throughout
middle and late adulthood, showing that some abilities decline in middle and late
adulthood, but others that represent the accumulation of decades of knowledge can
advance into late adulthood.
II. Theories of Development
• John B. Watson (1878-1958), the founder of American behaviorism, viewed development
in terms of learning theory.
o He generally agreed with John Locke that children’s ideas, preferences, and skills are
shaped by experience.
• Arnold Gesell expressed the opposing idea that biological maturation—the unfolding of
genetically determined traits, structures, and functions—was the main principal of
development.
A. The Psychoanalytic Perspective
• A number of theories fall within the psychoanalytic perspective.
o Each owes its origin to Sigmund Freud and views children—and adults—as
caught in conflict.
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• The expression of basic drives, such as sex and aggression, conflict with parental
expectations, social rules, moral codes, even laws.
o But the external limits—parental demands and social rules—are brought inside or
internalized.
o Once internalization occurs, the conflict takes place between opposing inner
forces.
• Freud’s theory of psychosexual development and Erik Erickson’s theory of
psychosocial development are stage theories that see children developing through
distinct periods of life.
o Each suggests that the child’s experiences during early stages affect the child’s
emotional and social life at the time and later on.
Sigmund Freud’s Theory of Psychosexual Development
• Sigmund Freud’s (1856-1939) theory of psychosexual development focused on the
following three parts of the personality.
o Id: It is present at birth and is unconscious.
▪ It represents biological drives and demands instant gratification, as
suggested by a baby’s wailing.
o Ego: It curbs the appetites of the id and makes plans that are in keeping with
social conventions so that a person can find gratification but avoid social
disapproval.
o Superego: It develops throughout infancy and early childhood.
▪ It brings inward the wishes and morals of the child’s caregivers and other
members of the community.
• According to Freud, the following are the five stages of psychosexual development.
o Oral stage: During the first year of life, “oral” activities such as sucking and
biting bring pleasure and gratification.
o Anal stage: During this stage, gratification is obtained through control and
elimination of waste products.
o Phallic stage: During this stage, parent-child conflict may develop over
masturbation, which many parents treat with punishment and threats.
o Latency stage: By age five or six, Freud believed, children enter this stage
during which sexual feelings remain unconscious, children turn to schoolwork,
and they typically prefer playmates of their own sex.
o Genital stage: The final stage of psychosexual development begins with the
biological changes that usher in adolescence.
▪ Adolescents generally desire sexual gratification through intercourse with
a member of the other sex.
• The expression of basic drives, such as sex and aggression, conflict with parental
expectations, social rules, moral codes, even laws.
o But the external limits—parental demands and social rules—are brought inside or
internalized.
o Once internalization occurs, the conflict takes place between opposing inner
forces.
• Freud’s theory of psychosexual development and Erik Erickson’s theory of
psychosocial development are stage theories that see children developing through
distinct periods of life.
o Each suggests that the child’s experiences during early stages affect the child’s
emotional and social life at the time and later on.
Sigmund Freud’s Theory of Psychosexual Development
• Sigmund Freud’s (1856-1939) theory of psychosexual development focused on the
following three parts of the personality.
o Id: It is present at birth and is unconscious.
▪ It represents biological drives and demands instant gratification, as
suggested by a baby’s wailing.
o Ego: It curbs the appetites of the id and makes plans that are in keeping with
social conventions so that a person can find gratification but avoid social
disapproval.
o Superego: It develops throughout infancy and early childhood.
▪ It brings inward the wishes and morals of the child’s caregivers and other
members of the community.
• According to Freud, the following are the five stages of psychosexual development.
o Oral stage: During the first year of life, “oral” activities such as sucking and
biting bring pleasure and gratification.
o Anal stage: During this stage, gratification is obtained through control and
elimination of waste products.
o Phallic stage: During this stage, parent-child conflict may develop over
masturbation, which many parents treat with punishment and threats.
o Latency stage: By age five or six, Freud believed, children enter this stage
during which sexual feelings remain unconscious, children turn to schoolwork,
and they typically prefer playmates of their own sex.
o Genital stage: The final stage of psychosexual development begins with the
biological changes that usher in adolescence.
▪ Adolescents generally desire sexual gratification through intercourse with
a member of the other sex.
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Evaluation
• Freud’s views about the anal stage have influenced child-care workers to
recommend that toilet training not be started too early or handled punitively.
o His emphasis on the emotional needs of children has influenced educators to
be more sensitive to the possible emotional reasons behind a child’s
misbehavior.
• Freud’s work has also been criticized.
o For one thing, Freud developed his theory on the basis of contacts with adult
patients (mostly women) (Henley, 2019), rather than observing children
directly.
o Some of Freud’s own disciples, including Erik Erikson, believe that Freud
placed too much emphasis on basic instincts and unconscious motives.
Erik Erikson’s Theory of Psychosocial Development
• Erik Erikson (1902-1994) modified Freud’s theory and extended it through the adult
years.
o Erikson’s theory, like Freud’s, focuses on the development of the emotional
life and psychological traits, but Erikson focuses on social relationships rather
than sexual or aggressive instincts.
o Therefore, Erikson speaks of psychosocial development rather than of
psychosexual development.
o Furthermore, Erikson places greater emphasis on the ego, or the sense of self.
• Erikson (1963) extended Freud’s five stages to eight to include the concerns of
adulthood.
o Rather than label his stages after parts of the body, Erikson labeled them after
the life crisis—an internal conflict that attends each stage of psychosocial
development—that people might encounter during that stage.
• Early experiences affect future developments.
o Successful resolution of each crisis bolsters children’s sense of identity—of
who they are and what they stand for—and their future expectation of future
success.
• Erikson’s views, like Freud’s, have influenced child rearing, early childhood
education, and child therapy.
o For example, Erikson’s views about an adolescent identity crisis—a period of
inner conflict during which one examines one’s values and makes decisions
about one’s life roles—have entered the popular culture and have affected the
way many parents and teachers deal with teenagers.
Evaluation
• Freud’s views about the anal stage have influenced child-care workers to
recommend that toilet training not be started too early or handled punitively.
o His emphasis on the emotional needs of children has influenced educators to
be more sensitive to the possible emotional reasons behind a child’s
misbehavior.
• Freud’s work has also been criticized.
o For one thing, Freud developed his theory on the basis of contacts with adult
patients (mostly women) (Henley, 2019), rather than observing children
directly.
o Some of Freud’s own disciples, including Erik Erikson, believe that Freud
placed too much emphasis on basic instincts and unconscious motives.
Erik Erikson’s Theory of Psychosocial Development
• Erik Erikson (1902-1994) modified Freud’s theory and extended it through the adult
years.
o Erikson’s theory, like Freud’s, focuses on the development of the emotional
life and psychological traits, but Erikson focuses on social relationships rather
than sexual or aggressive instincts.
o Therefore, Erikson speaks of psychosocial development rather than of
psychosexual development.
o Furthermore, Erikson places greater emphasis on the ego, or the sense of self.
• Erikson (1963) extended Freud’s five stages to eight to include the concerns of
adulthood.
o Rather than label his stages after parts of the body, Erikson labeled them after
the life crisis—an internal conflict that attends each stage of psychosocial
development—that people might encounter during that stage.
• Early experiences affect future developments.
o Successful resolution of each crisis bolsters children’s sense of identity—of
who they are and what they stand for—and their future expectation of future
success.
• Erikson’s views, like Freud’s, have influenced child rearing, early childhood
education, and child therapy.
o For example, Erikson’s views about an adolescent identity crisis—a period of
inner conflict during which one examines one’s values and makes decisions
about one’s life roles—have entered the popular culture and have affected the
way many parents and teachers deal with teenagers.
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Evaluation
• Erikson’s views are appealing in that they emphasize the importance of human
consciousness and choice.
o There is also some empirical support for the Eriksonian view that positive
outcomes of early life crises help put people on the path to positive
development (Gfellner & Cordoba, 2017; Marcia, 2010).
B. The Learning Perspective: Behavioral and Social Cognitive Theories
Behaviorism
• John B. Watson argued that a scientific approach to development must focus on
observable behavior only and not on things like thoughts, fantasies, and other mental
images.
• Classical conditioning is a simple form of learning in which an originally neutral
stimulus comes to bring forth, or elicit, the response usually brought forth by a
second stimulus as a result of being paired repeatedly with the second stimulus.
• Behaviorists argue that much emotional learning is acquired through classical
conditioning.
• In operant conditioning, children learn to do something because of its effects.
• B. F. Skinner introduced the key concept of reinforcement.
o Reinforcers are stimuli that increase the frequency of the behavior they follow.
• Skinner distinguished between positive and negative reinforcers.
o Positive reinforcers increase the frequency of behaviors when they are
applied. Food and approval usually serve as positive reinforcers.
o Negative reinforcers increase the frequency of behaviors when they are
removed. Fear acts as a negative reinforcer in that its removal increases the
frequency of the behaviors preceding it.
• Extinction results from repeated performance of operant behavior without
reinforcement.
o Punishments are aversive events that suppress or decrease the frequency of the
behavior they follow.
• Operant conditioning is used every day in the socialization of young children.
o Parents and peers influence children to acquire behavior patterns they consider
to be appropriate to their gender through the elaborate use of rewards and
punishments.
o Boys may ignore other boys when they play with dolls and housekeeping toys,
but play with boys when they use transportation toys. This type of conditioning
is obviously restrictive and harmful when it counters the child’s personal
Evaluation
• Erikson’s views are appealing in that they emphasize the importance of human
consciousness and choice.
o There is also some empirical support for the Eriksonian view that positive
outcomes of early life crises help put people on the path to positive
development (Gfellner & Cordoba, 2017; Marcia, 2010).
B. The Learning Perspective: Behavioral and Social Cognitive Theories
Behaviorism
• John B. Watson argued that a scientific approach to development must focus on
observable behavior only and not on things like thoughts, fantasies, and other mental
images.
• Classical conditioning is a simple form of learning in which an originally neutral
stimulus comes to bring forth, or elicit, the response usually brought forth by a
second stimulus as a result of being paired repeatedly with the second stimulus.
• Behaviorists argue that much emotional learning is acquired through classical
conditioning.
• In operant conditioning, children learn to do something because of its effects.
• B. F. Skinner introduced the key concept of reinforcement.
o Reinforcers are stimuli that increase the frequency of the behavior they follow.
• Skinner distinguished between positive and negative reinforcers.
o Positive reinforcers increase the frequency of behaviors when they are
applied. Food and approval usually serve as positive reinforcers.
o Negative reinforcers increase the frequency of behaviors when they are
removed. Fear acts as a negative reinforcer in that its removal increases the
frequency of the behaviors preceding it.
• Extinction results from repeated performance of operant behavior without
reinforcement.
o Punishments are aversive events that suppress or decrease the frequency of the
behavior they follow.
• Operant conditioning is used every day in the socialization of young children.
o Parents and peers influence children to acquire behavior patterns they consider
to be appropriate to their gender through the elaborate use of rewards and
punishments.
o Boys may ignore other boys when they play with dolls and housekeeping toys,
but play with boys when they use transportation toys. This type of conditioning
is obviously restrictive and harmful when it counters the child’s personal
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desires.
Social Cognitive Theory
• Social cognitive theorists such as Albert Bandura (1986, 2011) have shown that
much learning occurs by observing other people, reading, and viewing characters in
the media.
• Observational learning occurs when children observe how parents cook, clean, or
repair a broken appliance.
• In social cognitive theory, the people after whom one patterns one’s own behavior
are termed models.
Evaluation of Learning Theories
• Learning theories allow people to explain, predict, and influence many aspects of
behavior.
• Many of the teaching approaches used in educational TV shows are based on
learning theory.
C. The Cognitive Perspective
• Cognitive theorists focus on people’s mental processes.
• One cognitive perspective is cognitive-developmental theory, advanced by Swiss
biologist Jean Piaget (1896-1980) and further developed by many theorists.
o This theory holds that the child’s abilities to mentally represent the world and
solve problems unfold as a result of the interaction of experience and the
maturation of neurological structures.
Cognitive-Developmental Theory
• Through his studies, Piaget realized that when children answered questions
incorrectly, their wrong answers still often reflected consistent—although illogical—
mental processes.
• Piaget used the following concepts to describe and explain cognitive development.
o Schemes: It is a pattern of action or mental structure that is involved in
acquiring or organizing knowledge.
o Adaptation: It is the interaction between the organism and the environment. It
consists of assimilation and accommodation, which occur throughout life.
o Assimilation: It is the process by which someone responds to new object or
events according to existing schemes or ways of organizing knowledge.
desires.
Social Cognitive Theory
• Social cognitive theorists such as Albert Bandura (1986, 2011) have shown that
much learning occurs by observing other people, reading, and viewing characters in
the media.
• Observational learning occurs when children observe how parents cook, clean, or
repair a broken appliance.
• In social cognitive theory, the people after whom one patterns one’s own behavior
are termed models.
Evaluation of Learning Theories
• Learning theories allow people to explain, predict, and influence many aspects of
behavior.
• Many of the teaching approaches used in educational TV shows are based on
learning theory.
C. The Cognitive Perspective
• Cognitive theorists focus on people’s mental processes.
• One cognitive perspective is cognitive-developmental theory, advanced by Swiss
biologist Jean Piaget (1896-1980) and further developed by many theorists.
o This theory holds that the child’s abilities to mentally represent the world and
solve problems unfold as a result of the interaction of experience and the
maturation of neurological structures.
Cognitive-Developmental Theory
• Through his studies, Piaget realized that when children answered questions
incorrectly, their wrong answers still often reflected consistent—although illogical—
mental processes.
• Piaget used the following concepts to describe and explain cognitive development.
o Schemes: It is a pattern of action or mental structure that is involved in
acquiring or organizing knowledge.
o Adaptation: It is the interaction between the organism and the environment. It
consists of assimilation and accommodation, which occur throughout life.
o Assimilation: It is the process by which someone responds to new object or
events according to existing schemes or ways of organizing knowledge.
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o Accommodation: It is the modification of existing schemes to permit the
incorporation of new events or knowledge.
o Equilibration: It is the creation of an equilibrium, or balance, between
assimilation and accommodation.
Piaget’s Stages of Cognitive Development
• Piaget identified four major stages of cognitive development: sensorimotor,
preoperational, concrete operational, and formal operational.
• Because Piaget’s theory focuses on cognitive development, its applications are
primarily in educational settings.
• Piaget’s theory ends with formal operational thought.
Evaluation
• Many researchers, using a variety of methods, find that Piaget may have
underestimated the ages when children are capable of doing certain things.
o It also appears that many cognitive skills may develop gradually and not in
distinct stages.
Information-Processing Theory
• Many psychologists and educators speak of people as having working or short-term
memory and a more permanent long-term memory (storage).
o Thus, many cognitive psychologists focus on information processing in
people—the processes by which people encode (input) information, store it
(long-term memory), retrieve it (place it in short-term memory), and
manipulate it to solve problems.
• People’s strategies for solving problems are sometimes referred to as their “mental
programs” or “software.”
o In this computer metaphor, people’s brains are the “hardware” that runs their
mental programs.
o People’s brains—containing billions of brain cells called neurons—become
their most “personal” computers.
• When psychologists who study information processing contemplate cognitive
development, they are likely to talk in terms of the size of the person’s short-term
memory and the number of programs she or he can run simultaneously.
o Accommodation: It is the modification of existing schemes to permit the
incorporation of new events or knowledge.
o Equilibration: It is the creation of an equilibrium, or balance, between
assimilation and accommodation.
Piaget’s Stages of Cognitive Development
• Piaget identified four major stages of cognitive development: sensorimotor,
preoperational, concrete operational, and formal operational.
• Because Piaget’s theory focuses on cognitive development, its applications are
primarily in educational settings.
• Piaget’s theory ends with formal operational thought.
Evaluation
• Many researchers, using a variety of methods, find that Piaget may have
underestimated the ages when children are capable of doing certain things.
o It also appears that many cognitive skills may develop gradually and not in
distinct stages.
Information-Processing Theory
• Many psychologists and educators speak of people as having working or short-term
memory and a more permanent long-term memory (storage).
o Thus, many cognitive psychologists focus on information processing in
people—the processes by which people encode (input) information, store it
(long-term memory), retrieve it (place it in short-term memory), and
manipulate it to solve problems.
• People’s strategies for solving problems are sometimes referred to as their “mental
programs” or “software.”
o In this computer metaphor, people’s brains are the “hardware” that runs their
mental programs.
o People’s brains—containing billions of brain cells called neurons—become
their most “personal” computers.
• When psychologists who study information processing contemplate cognitive
development, they are likely to talk in terms of the size of the person’s short-term
memory and the number of programs she or he can run simultaneously.
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D. The Biological Perspective
• The biological perspective directly relates to physical development: to gains in height
and weight; development of the brain; and developments connected with hormones,
reproduction, and heredity.
Evolutionary Psychology and Ethology: “Doing What Comes Naturally”
• Evolutionary psychology and ethology were heavily influenced by the 19th-century
work of Charles Darwin and by the work of 20th-century ethologists Konrad Lorenz,
and Niko Tinbergen.
• Ethology—study of behaviors that are specific to a species—is concerned with
instinctive, or inborn, behavior patterns.
• The field of evolutionary psychology studies the ways in which adaptation and
natural selection are connected with mental processes and behavior.
o One of the concepts of evolutionary psychology is that not only physical traits
but also patterns of behavior, including social behavior, evolve and are
transmitted genetically from generation to generation.
o The behavior patterns are termed instinctive or species-specific because they
evolved within certain species.
• The nervous systems of most, and perhaps all, animals are “prewired” to respond to
some situations in specific ways.
o These behaviors are “built in,” or instinctive.
o They are also referred to as inborn fixed action patterns (FAPs)—a
stereotyped pattern of behavior that is evoked by a “releasing stimulus.”
• During prenatal development, genes and sex hormones are responsible for the
physical development of female and male sex organs.
• Research into the ethological perspective suggests that instinct may play a role in
human behavior.
E. The Ecological Perspective
• Ecology is the branch of biology that deals with the relationships between living
organisms and the environment.
• The ecological systems theory of development addresses aspects of psychological,
social, and emotional development as well as aspects of biological development.
o Ecological systems theorists explain development in terms of the interaction
between people and the settings in which they live (Bronfenbrenner & Morris,
2006).
• According to Urie Bronfenbrenner (1917-2005), for example, people need to focus on
D. The Biological Perspective
• The biological perspective directly relates to physical development: to gains in height
and weight; development of the brain; and developments connected with hormones,
reproduction, and heredity.
Evolutionary Psychology and Ethology: “Doing What Comes Naturally”
• Evolutionary psychology and ethology were heavily influenced by the 19th-century
work of Charles Darwin and by the work of 20th-century ethologists Konrad Lorenz,
and Niko Tinbergen.
• Ethology—study of behaviors that are specific to a species—is concerned with
instinctive, or inborn, behavior patterns.
• The field of evolutionary psychology studies the ways in which adaptation and
natural selection are connected with mental processes and behavior.
o One of the concepts of evolutionary psychology is that not only physical traits
but also patterns of behavior, including social behavior, evolve and are
transmitted genetically from generation to generation.
o The behavior patterns are termed instinctive or species-specific because they
evolved within certain species.
• The nervous systems of most, and perhaps all, animals are “prewired” to respond to
some situations in specific ways.
o These behaviors are “built in,” or instinctive.
o They are also referred to as inborn fixed action patterns (FAPs)—a
stereotyped pattern of behavior that is evoked by a “releasing stimulus.”
• During prenatal development, genes and sex hormones are responsible for the
physical development of female and male sex organs.
• Research into the ethological perspective suggests that instinct may play a role in
human behavior.
E. The Ecological Perspective
• Ecology is the branch of biology that deals with the relationships between living
organisms and the environment.
• The ecological systems theory of development addresses aspects of psychological,
social, and emotional development as well as aspects of biological development.
o Ecological systems theorists explain development in terms of the interaction
between people and the settings in which they live (Bronfenbrenner & Morris,
2006).
• According to Urie Bronfenbrenner (1917-2005), for example, people need to focus on
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the two-way interactions between the child and the parents, not just maturational forces
(nature) or child-rearing practices (nurture).
o Bronfenbrenner suggested that people can view the setting or contexts of human
development as consisting of multiple systems, each embedded within the next
larger context (Bronfenbrenner & Morris, 2006; Losike-Sedimo, 2018).
• From narrowest to widest, Bronfenbrenner’s systems are as follows:
o Microsystem: This involves the interactions of the child and other people in the
immediate setting, such as the home, the school, or the peer group.
o Mesosystem: This involves the interactions of the various settings within the
microsystem. For instance, the home and the school interact during parent–teacher
conferences.
o Exosystem: This involves the institutions in which the child does not directly
participate but which exert an indirect influence on the child. For example, the
school board is part of the child’s exosystem because board members put together
programs for the child’s education, determine what textbooks will be acceptable,
and so forth.
o Macrosystem: This involves the interaction of children with the beliefs, values,
expectations, and lifestyles of their cultural settings.
o Chronosystem: This considers the changes that occur over time. For example, the
effects of divorce peak about a year after the event, and then children begin to
recover.
F. The Sociocultural Perspective
• The sociocultural perspective teaches that people are social beings who are affected by
the cultures in which they live.
• Developmentalists use the term sociocultural in a couple of different ways.
o One refers quite specifically to the sociocultural theory of Russian psychologist
Lev Semenovich Vygotsky (1896-1934).
o The other addresses the effect of human diversity on people, including such
factors as ethnicity and gender.
Vygotsky’s Sociocultural Theory
• Whereas genetics is concerned with the biological transmission of traits from
generation to generation, Vygotsky’s (1978) theory is concerned with the
transmission of information and cognitive skills from generation to generation.
o Like Piaget, Vygotsky sees the child’s functioning as adaptive, and the child
adapts to his or her social and cultural interactions.
• Key concepts in Vygotsky’s theory include the following:
the two-way interactions between the child and the parents, not just maturational forces
(nature) or child-rearing practices (nurture).
o Bronfenbrenner suggested that people can view the setting or contexts of human
development as consisting of multiple systems, each embedded within the next
larger context (Bronfenbrenner & Morris, 2006; Losike-Sedimo, 2018).
• From narrowest to widest, Bronfenbrenner’s systems are as follows:
o Microsystem: This involves the interactions of the child and other people in the
immediate setting, such as the home, the school, or the peer group.
o Mesosystem: This involves the interactions of the various settings within the
microsystem. For instance, the home and the school interact during parent–teacher
conferences.
o Exosystem: This involves the institutions in which the child does not directly
participate but which exert an indirect influence on the child. For example, the
school board is part of the child’s exosystem because board members put together
programs for the child’s education, determine what textbooks will be acceptable,
and so forth.
o Macrosystem: This involves the interaction of children with the beliefs, values,
expectations, and lifestyles of their cultural settings.
o Chronosystem: This considers the changes that occur over time. For example, the
effects of divorce peak about a year after the event, and then children begin to
recover.
F. The Sociocultural Perspective
• The sociocultural perspective teaches that people are social beings who are affected by
the cultures in which they live.
• Developmentalists use the term sociocultural in a couple of different ways.
o One refers quite specifically to the sociocultural theory of Russian psychologist
Lev Semenovich Vygotsky (1896-1934).
o The other addresses the effect of human diversity on people, including such
factors as ethnicity and gender.
Vygotsky’s Sociocultural Theory
• Whereas genetics is concerned with the biological transmission of traits from
generation to generation, Vygotsky’s (1978) theory is concerned with the
transmission of information and cognitive skills from generation to generation.
o Like Piaget, Vygotsky sees the child’s functioning as adaptive, and the child
adapts to his or her social and cultural interactions.
• Key concepts in Vygotsky’s theory include the following:
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o Zone of proximal development (ZPD): This refers to a range of tasks that a
child can carry out with the help of someone who is more skilled, as in an
apprenticeship.
o Scaffolding: This is Vygotsky’s term for temporary cognitive structures or
methods of solving problems that help the child as he or she learns to function
independently.
G. Human Diversity
• The sociocultural perspective asserts that people cannot understand individuals without
awareness of the richness of their diversity (Markus, 2016; Tatto et al., 2017).
o For example, people differ in their ethnicity (cultural heritage, race, language, and
common history), their gender, and their socioeconomic status.
• Studying diversity is important so that students have appropriate educational
experiences.
o To teach students and guide their learning, educators need to understand
children’s family values and cultural expectations.
• Gender is another aspect of human diversity.
o It is the psychological state of being male or being female, as influenced by
cultural concepts of gender-appropriate behavior.
o Expectations of females and males are often polarized by cultural expectations.
o Males may differ from females in some respects, but history has created more
burdens for women than men as a result.
o Historically, females have been discouraged from careers in the sciences, politics,
and business.
o Women today earn more than half of the undergraduate degrees in the so-called
STEM field of biology, chemistry and mathematics (Cheryan et al., 2017).
o Women are making inroads into academic and vocational spheres such as
medicine, law engineering, and the military—traditionally male fields.
o Most college students in the United States are female, but there remain many parts
of the world in which women are prevented from obtaining an education
(Yousafazi & Lamb, 2013).
III. Controversies in Development
A. The Nature-Nurture Controversy
• Researchers are continually trying to sort out the extent to which human behavior is the
result of nature (heredity) and of nurture (environmental influences).
o Scientists seek the natural causes of development in children’s genetic heritage,
o Zone of proximal development (ZPD): This refers to a range of tasks that a
child can carry out with the help of someone who is more skilled, as in an
apprenticeship.
o Scaffolding: This is Vygotsky’s term for temporary cognitive structures or
methods of solving problems that help the child as he or she learns to function
independently.
G. Human Diversity
• The sociocultural perspective asserts that people cannot understand individuals without
awareness of the richness of their diversity (Markus, 2016; Tatto et al., 2017).
o For example, people differ in their ethnicity (cultural heritage, race, language, and
common history), their gender, and their socioeconomic status.
• Studying diversity is important so that students have appropriate educational
experiences.
o To teach students and guide their learning, educators need to understand
children’s family values and cultural expectations.
• Gender is another aspect of human diversity.
o It is the psychological state of being male or being female, as influenced by
cultural concepts of gender-appropriate behavior.
o Expectations of females and males are often polarized by cultural expectations.
o Males may differ from females in some respects, but history has created more
burdens for women than men as a result.
o Historically, females have been discouraged from careers in the sciences, politics,
and business.
o Women today earn more than half of the undergraduate degrees in the so-called
STEM field of biology, chemistry and mathematics (Cheryan et al., 2017).
o Women are making inroads into academic and vocational spheres such as
medicine, law engineering, and the military—traditionally male fields.
o Most college students in the United States are female, but there remain many parts
of the world in which women are prevented from obtaining an education
(Yousafazi & Lamb, 2013).
III. Controversies in Development
A. The Nature-Nurture Controversy
• Researchers are continually trying to sort out the extent to which human behavior is the
result of nature (heredity) and of nurture (environmental influences).
o Scientists seek the natural causes of development in children’s genetic heritage,
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the functioning of the nervous system, and in maturation.
o Scientists seek the environmental causes of development in children’s nutrition,
cultural and family backgrounds, and opportunities to learn about the world,
including cognitive stimulation during early childhood and formal education.
• Today, nearly all researchers agree that nature and nurture play important roles in nearly
every area of development.
B. The Continuity-Discontinuity Controversy
• Some developmentalists view human development as a continuous process in which the
effects of learning mount gradually, with no major sudden qualitative changes.
o In contrast, other theorists believe that a number of rapid qualitative changes usher
in new stages of development.
• Stage theorists such as Sigmund Freud and Jean Piaget saw development as
discontinuous.
o They saw biological changes as providing the potential for psychological changes.
• Certain aspects of physical development do occur in stages.
o However, psychologists disagree on whether developments in cognition occur in
stages.
C. The Active-Passive Controversy
• Historical views of children as willful and unruly suggest that people have generally
seen children as active, even if mischievous (at best) or evil (at worst).
o John Locke introduced a view of children as passive beings (blank tablets);
experience “wrote” features of personality and moral virtue on them.
• At one extreme, educators who view children as passive may assume that they must be
motivated to learn by their instructors.
o At the other extreme, educators who view children as active may assume that they
have a natural love of learning.
• These debates are theoretical.
o Scientists value theory for its ability to tie together observations and suggest new
areas of investigation, but scientists also follow an empirical approach.
o That is, they engage in research methods to find evidence for or against various
theoretical positions.
IV. How do We Study Development?
• Strong arguments or reference to authority figures are not evidence.
• Scientific evidence is obtained only by gathering sound information and conducting
the functioning of the nervous system, and in maturation.
o Scientists seek the environmental causes of development in children’s nutrition,
cultural and family backgrounds, and opportunities to learn about the world,
including cognitive stimulation during early childhood and formal education.
• Today, nearly all researchers agree that nature and nurture play important roles in nearly
every area of development.
B. The Continuity-Discontinuity Controversy
• Some developmentalists view human development as a continuous process in which the
effects of learning mount gradually, with no major sudden qualitative changes.
o In contrast, other theorists believe that a number of rapid qualitative changes usher
in new stages of development.
• Stage theorists such as Sigmund Freud and Jean Piaget saw development as
discontinuous.
o They saw biological changes as providing the potential for psychological changes.
• Certain aspects of physical development do occur in stages.
o However, psychologists disagree on whether developments in cognition occur in
stages.
C. The Active-Passive Controversy
• Historical views of children as willful and unruly suggest that people have generally
seen children as active, even if mischievous (at best) or evil (at worst).
o John Locke introduced a view of children as passive beings (blank tablets);
experience “wrote” features of personality and moral virtue on them.
• At one extreme, educators who view children as passive may assume that they must be
motivated to learn by their instructors.
o At the other extreme, educators who view children as active may assume that they
have a natural love of learning.
• These debates are theoretical.
o Scientists value theory for its ability to tie together observations and suggest new
areas of investigation, but scientists also follow an empirical approach.
o That is, they engage in research methods to find evidence for or against various
theoretical positions.
IV. How do We Study Development?
• Strong arguments or reference to authority figures are not evidence.
• Scientific evidence is obtained only by gathering sound information and conducting
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research.
A. Gathering Information
• Researchers use various methods to gather information.
o For example, they may ask teachers or parents to report on the behavior of
children, use interviews or questionnaires with adults, or study statistics compiled
by the government or the United Nations.
Naturalistic Observation
• Naturalistic-observation studies are conducted in “the field”; that is, in the natural,
or real-life, settings in which they happen.
o In field studies, investigators observe the natural behavior of children in
settings such as homes, playgrounds, and classrooms and try not to interfere
with it.
The Case Study
• The case study is a carefully drawn account of the behavior of an individual.
o Parents who keep diaries of their children’s activities are involved in informal
case studies.
• In addition to direct observation, case studies may include questionnaires,
standardized tests—a test in which an individual’s score is compared to the scores
of a group of similar individuals—and interviews.
B. Correlational: Putting Things Together
• Researchers use the correlational method to determine whether one behavior or trait
being studied is related to, or correlated with, another.
• Correlation coefficient is a number ranging from +1.00 and –1.00 that expresses the
direction (positive or negative) and strength of the relationships between two variables.
• Positive correlation is a relationship between two variables in which one variable
increases as the other increases.
• Negative correlation is a relationship between two variables in which one variable
increases as the other variable decreases.
Limitations of Correlational Information
• Correlational information can reveal relationships between variables, but it does not
research.
A. Gathering Information
• Researchers use various methods to gather information.
o For example, they may ask teachers or parents to report on the behavior of
children, use interviews or questionnaires with adults, or study statistics compiled
by the government or the United Nations.
Naturalistic Observation
• Naturalistic-observation studies are conducted in “the field”; that is, in the natural,
or real-life, settings in which they happen.
o In field studies, investigators observe the natural behavior of children in
settings such as homes, playgrounds, and classrooms and try not to interfere
with it.
The Case Study
• The case study is a carefully drawn account of the behavior of an individual.
o Parents who keep diaries of their children’s activities are involved in informal
case studies.
• In addition to direct observation, case studies may include questionnaires,
standardized tests—a test in which an individual’s score is compared to the scores
of a group of similar individuals—and interviews.
B. Correlational: Putting Things Together
• Researchers use the correlational method to determine whether one behavior or trait
being studied is related to, or correlated with, another.
• Correlation coefficient is a number ranging from +1.00 and –1.00 that expresses the
direction (positive or negative) and strength of the relationships between two variables.
• Positive correlation is a relationship between two variables in which one variable
increases as the other increases.
• Negative correlation is a relationship between two variables in which one variable
increases as the other variable decreases.
Limitations of Correlational Information
• Correlational information can reveal relationships between variables, but it does not
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show cause and effect.
• It may seem logical to assume that exposure to violent media makes people more
aggressive, but it may also be that more aggressive people choose violent media.
o This research bias is termed a selection factor.
C. The Experiment: Trying Things Out
• The experiment is the preferred method for investigating questions of cause and effect.
• In the experiment, a group of research participants receives a treatment and another
group does not.
o The subjects are then observed to determine whether the treatment changes their
behavior.
• Experiments are usually undertaken to test a hypothesis—a proposition to be tested.
Independent and Dependent Variables
• Independent variable is a variable whose presence is manipulated by the
experimenters so that its effects can be determined.
• Dependent variable is a measure of an assumed effect of an independent variable.
Experimental and Control Groups
• Subjects in the experimental group receive the treatment, whereas subjects in the
control group do not.
o All other conditions are held constant for both groups.
Random Assignment
• Subjects should be assigned to experimental or control groups on a chance or random
basis.
• Ethical and practical considerations prevent researchers from doing experiments on
the effects of many life circumstances, such as divorce or different patterns of child
rearing.
• When experiments cannot ethically be performed on humans, researchers sometimes
carry them out with animals and try to generalize the findings to humans.
D. Longitudinal Research: Studying Development over Time
• In longitudinal research, the same people are observed repeatedly over time, and
changes in development, such as gains in height or changes in mental abilities, are
show cause and effect.
• It may seem logical to assume that exposure to violent media makes people more
aggressive, but it may also be that more aggressive people choose violent media.
o This research bias is termed a selection factor.
C. The Experiment: Trying Things Out
• The experiment is the preferred method for investigating questions of cause and effect.
• In the experiment, a group of research participants receives a treatment and another
group does not.
o The subjects are then observed to determine whether the treatment changes their
behavior.
• Experiments are usually undertaken to test a hypothesis—a proposition to be tested.
Independent and Dependent Variables
• Independent variable is a variable whose presence is manipulated by the
experimenters so that its effects can be determined.
• Dependent variable is a measure of an assumed effect of an independent variable.
Experimental and Control Groups
• Subjects in the experimental group receive the treatment, whereas subjects in the
control group do not.
o All other conditions are held constant for both groups.
Random Assignment
• Subjects should be assigned to experimental or control groups on a chance or random
basis.
• Ethical and practical considerations prevent researchers from doing experiments on
the effects of many life circumstances, such as divorce or different patterns of child
rearing.
• When experiments cannot ethically be performed on humans, researchers sometimes
carry them out with animals and try to generalize the findings to humans.
D. Longitudinal Research: Studying Development over Time
• In longitudinal research, the same people are observed repeatedly over time, and
changes in development, such as gains in height or changes in mental abilities, are
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recorded.
• In cross-sectional research, children of different ages are observed and compared.
o It is assumed that when a large number of children are chosen at random, the
differences found in the older age groups are a reflection of how the younger
children will develop, given time.
Longitudinal Studies
• The Terman Studies of Genius, begun in the 1920s, tracked children with high IQ
scores for more than 50 years.
o Male subjects, but not female subjects, went on to high achievements in the
professional world.
o Contemporary studies of women show that women with high intelligence
generally match the achievements of men and suggest that women of the earlier
era were held back by traditional gender-role expectations.
• Most longitudinal studies span months or a few years, not decades.
o For example, briefer longitudinal studies have found that the children of
divorced parents undergo the most severe adjustment problems within a few
months of the divorce, peaking at about a year.
• Longitudinal studies have drawbacks.
o For example, it can be difficult to enlist volunteers to participate in a study that
will last a lifetime.
o Many subjects fall out of touch as the years pass; others die.
Cross-Sectional Studies
• Because of the drawbacks of longitudinal studies, most research that compares
children of different ages is cross-sectional.
• A major challenge to cross-sectional research is the cohort effect.
o A cohort is a group of people born at about the same time.
o As a result, they experience cultural and other events unique to their age group.
o In other words, children and adults of different ages are not likely to have
shared similar cultural backgrounds.
• Children of past generations also grew up with different expectations about gender
roles and appropriate social behavior.
o Women in the Terman study generally chose motherhood over careers because
of the times.
• In longitudinal studies, researchers know that they have the same individuals as they
have developed over 5, 25, even 50 years or more.
o In cross-sectional research, researchers can only hope that they will be
recorded.
• In cross-sectional research, children of different ages are observed and compared.
o It is assumed that when a large number of children are chosen at random, the
differences found in the older age groups are a reflection of how the younger
children will develop, given time.
Longitudinal Studies
• The Terman Studies of Genius, begun in the 1920s, tracked children with high IQ
scores for more than 50 years.
o Male subjects, but not female subjects, went on to high achievements in the
professional world.
o Contemporary studies of women show that women with high intelligence
generally match the achievements of men and suggest that women of the earlier
era were held back by traditional gender-role expectations.
• Most longitudinal studies span months or a few years, not decades.
o For example, briefer longitudinal studies have found that the children of
divorced parents undergo the most severe adjustment problems within a few
months of the divorce, peaking at about a year.
• Longitudinal studies have drawbacks.
o For example, it can be difficult to enlist volunteers to participate in a study that
will last a lifetime.
o Many subjects fall out of touch as the years pass; others die.
Cross-Sectional Studies
• Because of the drawbacks of longitudinal studies, most research that compares
children of different ages is cross-sectional.
• A major challenge to cross-sectional research is the cohort effect.
o A cohort is a group of people born at about the same time.
o As a result, they experience cultural and other events unique to their age group.
o In other words, children and adults of different ages are not likely to have
shared similar cultural backgrounds.
• Children of past generations also grew up with different expectations about gender
roles and appropriate social behavior.
o Women in the Terman study generally chose motherhood over careers because
of the times.
• In longitudinal studies, researchers know that they have the same individuals as they
have developed over 5, 25, even 50 years or more.
o In cross-sectional research, researchers can only hope that they will be
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comparable.
Cross-Sequential Research
• Cross-sequential research combines the longitudinal and cross-sectional methods
so that many of their individual drawbacks are overcome.
• In the cross-sequential study, the full span of the ideal longitudinal study is broken
up into convenient segments.
• Assume that researchers wish to follow the attitudes of children toward gender roles
from the age of four through the age of 12.
o The typical longitudinal study would take eight years.
o Researchers can, however, divide this eight-year span in half by attaining two
samples of children (a cross-section) instead of one: four-year-olds and eight-
year-olds.
• An obvious advantage to this collapsed method is that the study is completed in four
years rather than eight years.
o Still, the testing and retesting of samples provides some of the continuity of the
longitudinal study.
• By observing both samples at the age of eight (a time lag comparison), researchers
can also determine whether they are, in fact, comparable or whether the four-year
difference in their birth date is associated with a cohort effect.
E. Ethical Considerations
• Researchers adhere to ethical standards that are intended to promote the dignity of the
individual, foster human welfare, and maintain scientific integrity.
• These standards also ensure that they do not use methods or treatments that harm
subjects.
o Researchers are not to use methods that may do physical or psychological harm.
o Participants (and parents, if participants are minors) must be informed of the
purposes of the research and about the research methods.
o Participants must provide voluntary consent to participate in the study.
o Participants may withdraw from the study at any time, for any reason
o Participants should be offered information about the results of the study.
• These guidelines present researchers with a number of hurdles to overcome before
proceeding with and while conducting research, but because they protect the welfare of
participants, the guidelines are valuable.
comparable.
Cross-Sequential Research
• Cross-sequential research combines the longitudinal and cross-sectional methods
so that many of their individual drawbacks are overcome.
• In the cross-sequential study, the full span of the ideal longitudinal study is broken
up into convenient segments.
• Assume that researchers wish to follow the attitudes of children toward gender roles
from the age of four through the age of 12.
o The typical longitudinal study would take eight years.
o Researchers can, however, divide this eight-year span in half by attaining two
samples of children (a cross-section) instead of one: four-year-olds and eight-
year-olds.
• An obvious advantage to this collapsed method is that the study is completed in four
years rather than eight years.
o Still, the testing and retesting of samples provides some of the continuity of the
longitudinal study.
• By observing both samples at the age of eight (a time lag comparison), researchers
can also determine whether they are, in fact, comparable or whether the four-year
difference in their birth date is associated with a cohort effect.
E. Ethical Considerations
• Researchers adhere to ethical standards that are intended to promote the dignity of the
individual, foster human welfare, and maintain scientific integrity.
• These standards also ensure that they do not use methods or treatments that harm
subjects.
o Researchers are not to use methods that may do physical or psychological harm.
o Participants (and parents, if participants are minors) must be informed of the
purposes of the research and about the research methods.
o Participants must provide voluntary consent to participate in the study.
o Participants may withdraw from the study at any time, for any reason
o Participants should be offered information about the results of the study.
• These guidelines present researchers with a number of hurdles to overcome before
proceeding with and while conducting research, but because they protect the welfare of
participants, the guidelines are valuable.
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Discussion Topics
Nature or Nurture?
Few traits are influenced purely by nature or nurture. Nature seems to dictate predominantly
physical characteristics, such as blood type and eye color. By contrast, nurture influences learned
abilities such as the specific language that one speaks. Babies are born with the ability to
understand all the phonemes in the world’s languages. But by six months, they can only
distinguish the phonemes in the languages being spoken around them. Most characteristics are
influenced by a combination of nature and nurture. Point out to students that most psychological
traits are influenced by both of these forces, but physical characteristics may also be a result of
nature and nurture. For instance, weight is influenced by a person’s genetic makeup and by the
diets in their environment.
Everyday Examples of Classical Conditioning and Operant Conditioning
Help students understand how classical conditioning affects their behavior by pointing out a few
everyday examples. This can also help students master the confusing terminology associated
with classical conditioning. Point out that this is really a learning of association. Following are
some examples.
• Thunderstorms
o US = loud clap of thunder
o UCR = jump or tense up
o CS = lightning
o UCR = tense up
• Fast-food commercial
o US = picture of juicy, delicious burger
o UCR = hunger or salivation
o CS = commercial jingle or song
o UCR = hunger
Note: Unlearned or unconditioned stimulus (US), unlearned or unconditioned response (UCR,
learned or conditioned stimulus (CS)
Operant conditioning is learning the effects that a particular behavior incurs, whether that is a
reinforcement or a punishment. Stress that reinforcements increase the frequency of a behavior
and can be positive (something added) or negative (something taken away). Explain that the
positive and negative should be associated with addition or subtraction, not with good or bad.
The following are some everyday examples.
• Positive reinforcement: A teenager cleans her room to earn allowance.
Discussion Topics
Nature or Nurture?
Few traits are influenced purely by nature or nurture. Nature seems to dictate predominantly
physical characteristics, such as blood type and eye color. By contrast, nurture influences learned
abilities such as the specific language that one speaks. Babies are born with the ability to
understand all the phonemes in the world’s languages. But by six months, they can only
distinguish the phonemes in the languages being spoken around them. Most characteristics are
influenced by a combination of nature and nurture. Point out to students that most psychological
traits are influenced by both of these forces, but physical characteristics may also be a result of
nature and nurture. For instance, weight is influenced by a person’s genetic makeup and by the
diets in their environment.
Everyday Examples of Classical Conditioning and Operant Conditioning
Help students understand how classical conditioning affects their behavior by pointing out a few
everyday examples. This can also help students master the confusing terminology associated
with classical conditioning. Point out that this is really a learning of association. Following are
some examples.
• Thunderstorms
o US = loud clap of thunder
o UCR = jump or tense up
o CS = lightning
o UCR = tense up
• Fast-food commercial
o US = picture of juicy, delicious burger
o UCR = hunger or salivation
o CS = commercial jingle or song
o UCR = hunger
Note: Unlearned or unconditioned stimulus (US), unlearned or unconditioned response (UCR,
learned or conditioned stimulus (CS)
Operant conditioning is learning the effects that a particular behavior incurs, whether that is a
reinforcement or a punishment. Stress that reinforcements increase the frequency of a behavior
and can be positive (something added) or negative (something taken away). Explain that the
positive and negative should be associated with addition or subtraction, not with good or bad.
The following are some everyday examples.
• Positive reinforcement: A teenager cleans her room to earn allowance.
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• Negative reinforcement: A teenager cleans her room to stop the annoying nagging of her
parents. Punishments decrease the frequency of a behavior and can be either positive or
negative.
• Positive punishment: A teenager is given additional chores for failing to clean her room.
• Negative punishment: A teenager is grounded for failing to clean her room, that is, her
social life is removed. Note that a student who is sent to his room that is filled with
gadgets, such as a TV, a computer, and an iPod, may not be experiencing a punishment.
Vygotsky vs. Piaget in Teaching
The developmental theories of Piaget and Vygotsky have implications for education. Have
students discuss the following questions in terms of the perspectives of each theorist: Would
Piaget or Vygotsky see the value of peer tutoring? How much teacher intervention should occur
in discovery learning? Which theorist provides a basic framework for helping teachers to know
what level of educational material is appropriate to teach to children of various ages? What are
the strengths of this perspective, and what are its limitations?
Collecting Data
While studying development, researches use various methods to gather information. According
to the text, researchers might ask the parents about the behavior of their children. Also,
information about the development can be achieved by observation. What other methods can
researchers use to gather relevant data, while studying development? Can they use survey
methods? What would be the targeted audience for such a survey? Does the data from already
available research stay true to the changing conditions and trends in the society? Can one rely on
the information that is already there? Discuss the different methods that are available for
collecting data and their advantages over the ones discussed in this chapter.
Class Activities and Projects
Designing Studies
There are many ways to examine issues of interest to child development. One issue that has often
been investigated is the theory that watching violent TV shows causes aggression in children.
Have students (either individually or in small groups) explain how they would study this using
the methods given below.
1. Naturalistic observations: Where would you conduct these observations? What behaviors
would you look for?
2. Case study: What kinds of behaviors would interest you?
3. Correlational study: What are the variables you are correlating? What would a positive
• Negative reinforcement: A teenager cleans her room to stop the annoying nagging of her
parents. Punishments decrease the frequency of a behavior and can be either positive or
negative.
• Positive punishment: A teenager is given additional chores for failing to clean her room.
• Negative punishment: A teenager is grounded for failing to clean her room, that is, her
social life is removed. Note that a student who is sent to his room that is filled with
gadgets, such as a TV, a computer, and an iPod, may not be experiencing a punishment.
Vygotsky vs. Piaget in Teaching
The developmental theories of Piaget and Vygotsky have implications for education. Have
students discuss the following questions in terms of the perspectives of each theorist: Would
Piaget or Vygotsky see the value of peer tutoring? How much teacher intervention should occur
in discovery learning? Which theorist provides a basic framework for helping teachers to know
what level of educational material is appropriate to teach to children of various ages? What are
the strengths of this perspective, and what are its limitations?
Collecting Data
While studying development, researches use various methods to gather information. According
to the text, researchers might ask the parents about the behavior of their children. Also,
information about the development can be achieved by observation. What other methods can
researchers use to gather relevant data, while studying development? Can they use survey
methods? What would be the targeted audience for such a survey? Does the data from already
available research stay true to the changing conditions and trends in the society? Can one rely on
the information that is already there? Discuss the different methods that are available for
collecting data and their advantages over the ones discussed in this chapter.
Class Activities and Projects
Designing Studies
There are many ways to examine issues of interest to child development. One issue that has often
been investigated is the theory that watching violent TV shows causes aggression in children.
Have students (either individually or in small groups) explain how they would study this using
the methods given below.
1. Naturalistic observations: Where would you conduct these observations? What behaviors
would you look for?
2. Case study: What kinds of behaviors would interest you?
3. Correlational study: What are the variables you are correlating? What would a positive
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correlation indicate? What would a negative correlation indicate?
4. Experimental study: What is the independent variable (IV)? What is the dependent variable
(DV)? What is the experimental group? What is the treatment group?
Make sure students discuss what evidence would support and contradict the theory, as well as the
pros and cons of each methodology.
Modifying Child Behavior Using the Principles of Operant Conditioning
Have students write a short paper making recommendations to a parent dealing with their two-
year-old’s temper tantrums to get a cookie in the grocery store. Make sure students identify
parent responses that would reinforce the tantrums and make them increase (e.g., giving attention
to the child or giving him or her the cookie), as well as behaviors that would extinguish the
behavior (e.g., ignoring them). Also, have students include a section on the possible
consequences of spanking in this situation. A review by E. Gershoff (2002) is available in
Psychological Bulletin, 128(4), 539-579 which students can use for this activity.
Child Rearing Over Three Generations
Have students interview their parents and grandparents about their experiences as children.
Include in the interview such parenting practices as sleeping arrangements, infant feeding,
discipline, household chores and responsibilities, after school activities, and rules for dating in
adolescence. Encourage students to be creative when they think about other changes and/or
differences for how children experienced childhood, even in recent times. Have students
organize their findings into a chart; list their experiences down the left-hand side of the paper and
their three generations across the top. Have students highlight the differences that surprised them
the most.
Scaffolding in Real Life: Assembling Puzzles with Children
If possible, invite children of various ages to class (i.e., a two-year-old, four-year-old, and six-
year-old). Have students help the children put together age-appropriate puzzles. Then have
students discuss the ways in which they helped to scaffold the children’s thinking. Students will
notice that the degree of assistance given to the younger children was more (perhaps showing
them where the pieces go) when compared with the older children (perhaps only suggesting to
start with the outside edges). This can also work as a class discussion if child participants are not
available.
Demonstration of Classical Conditioning: 3, 2, 1, POP!
correlation indicate? What would a negative correlation indicate?
4. Experimental study: What is the independent variable (IV)? What is the dependent variable
(DV)? What is the experimental group? What is the treatment group?
Make sure students discuss what evidence would support and contradict the theory, as well as the
pros and cons of each methodology.
Modifying Child Behavior Using the Principles of Operant Conditioning
Have students write a short paper making recommendations to a parent dealing with their two-
year-old’s temper tantrums to get a cookie in the grocery store. Make sure students identify
parent responses that would reinforce the tantrums and make them increase (e.g., giving attention
to the child or giving him or her the cookie), as well as behaviors that would extinguish the
behavior (e.g., ignoring them). Also, have students include a section on the possible
consequences of spanking in this situation. A review by E. Gershoff (2002) is available in
Psychological Bulletin, 128(4), 539-579 which students can use for this activity.
Child Rearing Over Three Generations
Have students interview their parents and grandparents about their experiences as children.
Include in the interview such parenting practices as sleeping arrangements, infant feeding,
discipline, household chores and responsibilities, after school activities, and rules for dating in
adolescence. Encourage students to be creative when they think about other changes and/or
differences for how children experienced childhood, even in recent times. Have students
organize their findings into a chart; list their experiences down the left-hand side of the paper and
their three generations across the top. Have students highlight the differences that surprised them
the most.
Scaffolding in Real Life: Assembling Puzzles with Children
If possible, invite children of various ages to class (i.e., a two-year-old, four-year-old, and six-
year-old). Have students help the children put together age-appropriate puzzles. Then have
students discuss the ways in which they helped to scaffold the children’s thinking. Students will
notice that the degree of assistance given to the younger children was more (perhaps showing
them where the pieces go) when compared with the older children (perhaps only suggesting to
start with the outside edges). This can also work as a class discussion if child participants are not
available.
Demonstration of Classical Conditioning: 3, 2, 1, POP!
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A simple demonstration can help students grasp the concepts involved in classical conditioning.
Kohn and Kalat (1991) discussed an activity involving several air-filled balloons and a long dart
or pin. To replicate this activity, students should inflate the balloons as much as possible so they
will easily pop. Tape the balloons to a table in front of the class. Ask students to pay attention to
their responses as you conduct the demonstration. Then, count down “3, 2, 1,” and pop the first
balloon (if you are in a large auditorium, try doing this activity near a microphone so that the
loud pop produces a startle response). Repeat this for the next few balloons. On the last balloon,
count down, but then miss the balloon. Most students will actually not flinch to the last
countdown. Ask the students to describe their responses. Then, help students to identify the
aspects of classical conditioning: UCS = loud popping sound, UCR = flinching or other startle
reaction, CS = countdown or hand movement, UCR = clinching muscles to prevent flinching.
Students may have trouble identifying these components.
Correlational Research and the Effects of Divorce on Children
Have students work through the following research questions concerning the effects of divorce
on children. This activity can be used as a way of expanding their understanding of research
design and related concepts (naturalistic, correlational, experimental designs, developmental
change investigation, independent and dependent variables, cause and effect, confounds, and
ethical considerations).
1. Why do we think there might be consequences of divorce on child development? What
kinds of naturalistic observational research may have supported these conclusions?
2. What might be some of the specific consequences of divorce on child development? What
kinds of correlational studies might be conducted by developmental psychologists to
examine whether or not there were reliable and valid relationships between divorce and
these consequences? What are the possible confounding variables in this type of research?
3. What might be some of the issues concerning age differences in relationships between
divorce and negative consequences? How could these be examined?
4. What kind of evidence might suggest that divorce causes negative consequences? What
other explanations might there be for any correlational findings between negative
consequences and divorce? What kind of research needs to be conducted to determine
cause and effect in this case? In this research, what is (are) the independent variable(s), and
what is (are) the dependent variable(s)?
5. In regard to ethical concerns, would any of this research be questionable? What might
those be, and how should a researcher deal with them?
Theoretical Positions of Developmental Theories
One way for students to appreciate the similarities and differences of the many developmental
theories presented in this chapter is to examine the stance each theory takes on the controversies
A simple demonstration can help students grasp the concepts involved in classical conditioning.
Kohn and Kalat (1991) discussed an activity involving several air-filled balloons and a long dart
or pin. To replicate this activity, students should inflate the balloons as much as possible so they
will easily pop. Tape the balloons to a table in front of the class. Ask students to pay attention to
their responses as you conduct the demonstration. Then, count down “3, 2, 1,” and pop the first
balloon (if you are in a large auditorium, try doing this activity near a microphone so that the
loud pop produces a startle response). Repeat this for the next few balloons. On the last balloon,
count down, but then miss the balloon. Most students will actually not flinch to the last
countdown. Ask the students to describe their responses. Then, help students to identify the
aspects of classical conditioning: UCS = loud popping sound, UCR = flinching or other startle
reaction, CS = countdown or hand movement, UCR = clinching muscles to prevent flinching.
Students may have trouble identifying these components.
Correlational Research and the Effects of Divorce on Children
Have students work through the following research questions concerning the effects of divorce
on children. This activity can be used as a way of expanding their understanding of research
design and related concepts (naturalistic, correlational, experimental designs, developmental
change investigation, independent and dependent variables, cause and effect, confounds, and
ethical considerations).
1. Why do we think there might be consequences of divorce on child development? What
kinds of naturalistic observational research may have supported these conclusions?
2. What might be some of the specific consequences of divorce on child development? What
kinds of correlational studies might be conducted by developmental psychologists to
examine whether or not there were reliable and valid relationships between divorce and
these consequences? What are the possible confounding variables in this type of research?
3. What might be some of the issues concerning age differences in relationships between
divorce and negative consequences? How could these be examined?
4. What kind of evidence might suggest that divorce causes negative consequences? What
other explanations might there be for any correlational findings between negative
consequences and divorce? What kind of research needs to be conducted to determine
cause and effect in this case? In this research, what is (are) the independent variable(s), and
what is (are) the dependent variable(s)?
5. In regard to ethical concerns, would any of this research be questionable? What might
those be, and how should a researcher deal with them?
Theoretical Positions of Developmental Theories
One way for students to appreciate the similarities and differences of the many developmental
theories presented in this chapter is to examine the stance each theory takes on the controversies
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of child development (i.e., nature-nurture, active-passive, and continuity-discontinuity). The
theories can be discussed in small groups or as a class.
Nature-Nurture Active-Passive Continuity-
Discontinuity
Freud’s Theory of
Psychosexual
Development
Both Passive Discontinuous
Erikson’s Theory
of Psychosocial
Development
Both Active Discontinuous
Watson’s
Behaviorism Nurture Passive Continuous
Bandura’s Social
Cognitive Theory Nurture Active Continuous
Piaget’s Cognitive-
Developmental
Theory
Both Active Discontinuous
Information-
Processing Theory Both Active Continuous
Lorenz’s Ethology Both (primarily
nature but early
experience is
necessary)
Passive Discontinuous (due to
early critical period)
Bronfenbrenner’s
Ecological Systems
Theory
Both Active Continuous
Vygotsky’s
Sociocultural
Theory
Both Active Continuous
Conducting Research
Ask students to select some negative (coming late to the class) and positive (taking notes in the
class) behaviors that are common among students. After selecting certain types of behaviors, ask
students to make a note of the governing factors of such behaviors. What methods would they
use to assess such behaviors? If time permits, students should conduct a survey in their class or
in groups to identify the governing factors of the behaviors chosen.
of child development (i.e., nature-nurture, active-passive, and continuity-discontinuity). The
theories can be discussed in small groups or as a class.
Nature-Nurture Active-Passive Continuity-
Discontinuity
Freud’s Theory of
Psychosexual
Development
Both Passive Discontinuous
Erikson’s Theory
of Psychosocial
Development
Both Active Discontinuous
Watson’s
Behaviorism Nurture Passive Continuous
Bandura’s Social
Cognitive Theory Nurture Active Continuous
Piaget’s Cognitive-
Developmental
Theory
Both Active Discontinuous
Information-
Processing Theory Both Active Continuous
Lorenz’s Ethology Both (primarily
nature but early
experience is
necessary)
Passive Discontinuous (due to
early critical period)
Bronfenbrenner’s
Ecological Systems
Theory
Both Active Continuous
Vygotsky’s
Sociocultural
Theory
Both Active Continuous
Conducting Research
Ask students to select some negative (coming late to the class) and positive (taking notes in the
class) behaviors that are common among students. After selecting certain types of behaviors, ask
students to make a note of the governing factors of such behaviors. What methods would they
use to assess such behaviors? If time permits, students should conduct a survey in their class or
in groups to identify the governing factors of the behaviors chosen.
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Answer Key: Truth or Fiction?
As an introduction to each chapter, several statements are presented for students’ consideration.
This is an excellent first class activity. For each question, you can ask students how confident
they are about their answers and, if they were confident (especially about questions they got
wrong), ask them where they thought their knowledge about the topic came from—personal
experience, another person, an expert perhaps, intuition, or common sense. Use this discussion to
highlight the importance of investigation and hypothesis testing in developmental psychology for
accurate understanding of behavioral phenomena.
Use of the scientific method involves collecting data on more than one person. The observations
need to be made by an unbiased observer, and reliable and valid measurement instruments need
to be used. In addition, care needs to be taken to control for confounding influences. Many times
over the course of the semester, students will feel they already “know” something about a topic
in child development only to find that the research does not support their position. Remind them
about this discussion early and often.
1. During the Middle Ages, children were often treated as miniature adults.
Truth. This does not mean that they were given more privileges, however. Instead, more
was expected of them (1-2).
2. Nail biting and smoking cigarettes are signs of conflict experienced during early childhood.
Fiction. Actually, there is no evidence that nail biting and smoking cigarettes are signs of
conflict experienced during early childhood. The statement must therefore be considered
“fiction” (1-2a).
3. Research with monkeys has helped psychologists understand the formation of attachment
in humans.
Truth. Researchers have exposed monkeys and other nonhuman animals to conditions that
would be unethical to use with humans (1-4c).
4. To learn how a person develops over a lifetime, researchers have tracked some individuals
for more than 50 years.
Truth. It is true that researchers have tracked some individuals for more than 50 years to
learn how a person develops over a lifetime. The Terman study did just that. What are the
advantages and disadvantages of longitudinal research as compared with cross-sectional
research? (1-4d)
Answer Key: Truth or Fiction?
As an introduction to each chapter, several statements are presented for students’ consideration.
This is an excellent first class activity. For each question, you can ask students how confident
they are about their answers and, if they were confident (especially about questions they got
wrong), ask them where they thought their knowledge about the topic came from—personal
experience, another person, an expert perhaps, intuition, or common sense. Use this discussion to
highlight the importance of investigation and hypothesis testing in developmental psychology for
accurate understanding of behavioral phenomena.
Use of the scientific method involves collecting data on more than one person. The observations
need to be made by an unbiased observer, and reliable and valid measurement instruments need
to be used. In addition, care needs to be taken to control for confounding influences. Many times
over the course of the semester, students will feel they already “know” something about a topic
in child development only to find that the research does not support their position. Remind them
about this discussion early and often.
1. During the Middle Ages, children were often treated as miniature adults.
Truth. This does not mean that they were given more privileges, however. Instead, more
was expected of them (1-2).
2. Nail biting and smoking cigarettes are signs of conflict experienced during early childhood.
Fiction. Actually, there is no evidence that nail biting and smoking cigarettes are signs of
conflict experienced during early childhood. The statement must therefore be considered
“fiction” (1-2a).
3. Research with monkeys has helped psychologists understand the formation of attachment
in humans.
Truth. Researchers have exposed monkeys and other nonhuman animals to conditions that
would be unethical to use with humans (1-4c).
4. To learn how a person develops over a lifetime, researchers have tracked some individuals
for more than 50 years.
Truth. It is true that researchers have tracked some individuals for more than 50 years to
learn how a person develops over a lifetime. The Terman study did just that. What are the
advantages and disadvantages of longitudinal research as compared with cross-sectional
research? (1-4d)
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Additional Reading Material
Kohn, A. & Kalat, J.W. (1992). Preparing for an important event: Demonstrating the modern
view of classical conditioning. Teaching of Psychology, 19(2), 100–102.
Video Suggestions
Theories of Development (1997, Insight Media, 29 minutes)
This video provides an overview of the cognitive, psychosexual, psychosocial, behaviorist,
social-learning, and sociocultural theories of child development.
Piaget’s Developmental Theory: An Overview (1989, Davidson Films, 25 minutes)
This video provides a good introduction or review of basic concepts, including interviews with
children by David Elkind.
Erik Erikson: A Life’s Work (1991, Films Media Group, 38 minutes)
This video integrates biographical information about Erikson with an overview of his eight-stage
psychosocial theory of human development.
B. F. Skinner: A Fresh Appraisal (1999, Davidson Films, 40 minutes)
This video includes both archival and recent footage and is narrated by Murray Sidman. It
clarifies some myths about behaviorism in the context of presentation of his theory and research.
His Own Best Subject: A Visit to B.F. Skinner’s Basement (2000, Davidson Films, 20 minutes)
This video consists of Skinner’s daughters discussing their father’s affection toward them and
the kind of attention he gave to them. They also give a tour of the basement in which he used to
write.
Vygotsky’s Developmental Theory: An Introduction (1994, Insight Media, 28 minutes)
This video provides a presentation of the basic concepts and vocabulary of Vygotsky’s
constructivist educational approach to development.
Innocence: What is a Child? (1997, Films for the Humanities and Social Sciences, 54 minutes)
This video provides historical perspectives on the construct of childhood innocence from the late
nineteenth century to the present.
Total Baby (1995, Filmakers Library, 59 minutes)
This video discusses childrearing as a reflection of societal and cultural views of the era and
examines ideas about children by different theorists (Aristotle, Dr. Spock).
Additional Reading Material
Kohn, A. & Kalat, J.W. (1992). Preparing for an important event: Demonstrating the modern
view of classical conditioning. Teaching of Psychology, 19(2), 100–102.
Video Suggestions
Theories of Development (1997, Insight Media, 29 minutes)
This video provides an overview of the cognitive, psychosexual, psychosocial, behaviorist,
social-learning, and sociocultural theories of child development.
Piaget’s Developmental Theory: An Overview (1989, Davidson Films, 25 minutes)
This video provides a good introduction or review of basic concepts, including interviews with
children by David Elkind.
Erik Erikson: A Life’s Work (1991, Films Media Group, 38 minutes)
This video integrates biographical information about Erikson with an overview of his eight-stage
psychosocial theory of human development.
B. F. Skinner: A Fresh Appraisal (1999, Davidson Films, 40 minutes)
This video includes both archival and recent footage and is narrated by Murray Sidman. It
clarifies some myths about behaviorism in the context of presentation of his theory and research.
His Own Best Subject: A Visit to B.F. Skinner’s Basement (2000, Davidson Films, 20 minutes)
This video consists of Skinner’s daughters discussing their father’s affection toward them and
the kind of attention he gave to them. They also give a tour of the basement in which he used to
write.
Vygotsky’s Developmental Theory: An Introduction (1994, Insight Media, 28 minutes)
This video provides a presentation of the basic concepts and vocabulary of Vygotsky’s
constructivist educational approach to development.
Innocence: What is a Child? (1997, Films for the Humanities and Social Sciences, 54 minutes)
This video provides historical perspectives on the construct of childhood innocence from the late
nineteenth century to the present.
Total Baby (1995, Filmakers Library, 59 minutes)
This video discusses childrearing as a reflection of societal and cultural views of the era and
examines ideas about children by different theorists (Aristotle, Dr. Spock).
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Research Methods for the Social Sciences (1995, Insight Media, 33 minutes)
This video provides an overview of the key concepts of experimental design and reviews the
different steps of the scientific method.
Research Methods in Psychology (2001, Insight Media, 28 minutes)
This video provides an overview of the observational and descriptive research designs (uses
example of correlational findings on aggressive behavior and video games).
Key Terms
Developmental psychology
Life-span perspective
Behaviorism
Maturation
Psychosexual development
Stage theory
Psychosocial development
Life crisis
Identity crisis
Classical conditioning
Operant conditioning
Reinforcement
Positive reinforcer
Negative reinforcer
Extinction
Social cognitive theory
Cognitive-developmental theory
Scheme
Adaptation
Assimilation
Accommodation
Equilibration
Ethology
Evolutionary psychology
Fixed action pattern (FAP)
Ecology
Ecological systems theory
Microsystem
Mesosystem
Exosystem
Macrosystem
Chronosystem
Zone of proximal development (ZPD)
Scaffolding
Nature
Nurture
Empirical
Naturalistic observation
Case study
Standardized tests
Correlation coefficient
Positive correlation
Negative correlation
Experiment
Hypothesis
Independent variable
Dependent variable
Experimental group
Control group
Longitudinal research
Cross-sectional research
Cohort effect
Cross-sequential research
Time lag
Research Methods for the Social Sciences (1995, Insight Media, 33 minutes)
This video provides an overview of the key concepts of experimental design and reviews the
different steps of the scientific method.
Research Methods in Psychology (2001, Insight Media, 28 minutes)
This video provides an overview of the observational and descriptive research designs (uses
example of correlational findings on aggressive behavior and video games).
Key Terms
Developmental psychology
Life-span perspective
Behaviorism
Maturation
Psychosexual development
Stage theory
Psychosocial development
Life crisis
Identity crisis
Classical conditioning
Operant conditioning
Reinforcement
Positive reinforcer
Negative reinforcer
Extinction
Social cognitive theory
Cognitive-developmental theory
Scheme
Adaptation
Assimilation
Accommodation
Equilibration
Ethology
Evolutionary psychology
Fixed action pattern (FAP)
Ecology
Ecological systems theory
Microsystem
Mesosystem
Exosystem
Macrosystem
Chronosystem
Zone of proximal development (ZPD)
Scaffolding
Nature
Nurture
Empirical
Naturalistic observation
Case study
Standardized tests
Correlation coefficient
Positive correlation
Negative correlation
Experiment
Hypothesis
Independent variable
Dependent variable
Experimental group
Control group
Longitudinal research
Cross-sectional research
Cohort effect
Cross-sequential research
Time lag
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1
Chapter 2
H e r e d i t y a n d P r e n a t a l D e v e l o p m e n t
Chapter Overview
This chapter provides an overview of the biological processes of heredity and conception,
including all of the basic structures (chromosomes, genes, and DNA) and processes (mitosis,
meiosis, fertilization, and implantation) involved in the formation of a new human being.
Students will learn the different causes and types of chromosomal and genetic abnormalities. The
relationship between genotype and phenotype in developmental outcome is described, and the
potential disorders resulting from various chromosomal and genetic abnormalities are discussed.
Research strategies for examining the contribution of genes and environment to development are
introduced. The chapter includes a discussion of infertility and genetic counseling, alternative
pregnancy methods, and parental attempts to select the gender of their child. A brief discussion
of the benefits of adopting children is presented. The chapter also describes the preimplantation
genetic diagnosis process. Students will be able to compare the different stages of prenatal
development (germinal, embryonic, and fetal), after reading this chapter. Sexual differentiation is
explained in detail. The role of amniotic sac, amniotic fluid, and placenta in the development and
delivery process is presented. The changes in the fetus throughout the pregnancy cycle are
explained. Students will be able to identify the different types of teratogens that can affect the
health of the developing fetus as well as the stage of development where harm can occur, after
reading this chapter. This chapter describes the impact of drugs that are the most likely to affect
the healthy development of a fetus (aspirin, thalidomide, hormones, vitamins, heroin, methadone,
marijuana, alcohol, cocaine, caffeine, and cigarettes). The chapter concludes with a discussion of
the environmental effects on the development of the fetus such as prenatal exposure to lead and
the age of the parents at conception.
Chapter Learning Objectives
After reading the chapter, students should be able to accomplish the objectives given below.
• Explain the difference between a gene and a chromosome, and explain how a baby’s sex is
determined
• Describe the processes of mitosis and meiosis
• Identify the difference between monozygotic and dizygotic twins and describe how they
are developed
• Describe the process of genetic transmission, or how traits are passed from parents to
children
• Discuss the causes and characteristics associated with chromosomal and genetic
Chapter 2
H e r e d i t y a n d P r e n a t a l D e v e l o p m e n t
Chapter Overview
This chapter provides an overview of the biological processes of heredity and conception,
including all of the basic structures (chromosomes, genes, and DNA) and processes (mitosis,
meiosis, fertilization, and implantation) involved in the formation of a new human being.
Students will learn the different causes and types of chromosomal and genetic abnormalities. The
relationship between genotype and phenotype in developmental outcome is described, and the
potential disorders resulting from various chromosomal and genetic abnormalities are discussed.
Research strategies for examining the contribution of genes and environment to development are
introduced. The chapter includes a discussion of infertility and genetic counseling, alternative
pregnancy methods, and parental attempts to select the gender of their child. A brief discussion
of the benefits of adopting children is presented. The chapter also describes the preimplantation
genetic diagnosis process. Students will be able to compare the different stages of prenatal
development (germinal, embryonic, and fetal), after reading this chapter. Sexual differentiation is
explained in detail. The role of amniotic sac, amniotic fluid, and placenta in the development and
delivery process is presented. The changes in the fetus throughout the pregnancy cycle are
explained. Students will be able to identify the different types of teratogens that can affect the
health of the developing fetus as well as the stage of development where harm can occur, after
reading this chapter. This chapter describes the impact of drugs that are the most likely to affect
the healthy development of a fetus (aspirin, thalidomide, hormones, vitamins, heroin, methadone,
marijuana, alcohol, cocaine, caffeine, and cigarettes). The chapter concludes with a discussion of
the environmental effects on the development of the fetus such as prenatal exposure to lead and
the age of the parents at conception.
Chapter Learning Objectives
After reading the chapter, students should be able to accomplish the objectives given below.
• Explain the difference between a gene and a chromosome, and explain how a baby’s sex is
determined
• Describe the processes of mitosis and meiosis
• Identify the difference between monozygotic and dizygotic twins and describe how they
are developed
• Describe the process of genetic transmission, or how traits are passed from parents to
children
• Discuss the causes and characteristics associated with chromosomal and genetic
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2
abnormalities
• Explain how Down syndrome occurs as well as its physical markers
• Describe how sex-linked chromosomal abnormalities occur
• Identify and compare the different sex-linked chromosomal disorders (Klinefelter
syndrome and Turner syndrome)
• Identify and compare disorders that have been contributed to genes (PKU, Huntington’s
disease, Sickle-Cell Anemia, Tay-Sachs disease, and Cystic Fibrosis)
• Identify and compare sex-linked genetic abnormalities (hemophilia, Duchenne muscular
dystrophy)
• Identify and explain different prenatal testing techniques used for various genetic disorders
• Describe how studies of kinship, adopted children, and identical (monozygotic) versus
fraternal (dizygotic) twins are used to explore the relative influences of nature (heredity)
versus nurture (environment)
• Explain the formation of eggs and sperm and where conception takes place
• To define the following terms: “ova,” “endometrium,” “sperm cells,” and “spontaneous
abortion”
• Discuss the causes of infertility and the methods that couples can use to conceive
• Discuss the benefits of adopting children
• Describe the preimplantation genetic diagnosis process
• Define and compare the different stages of prenatal development (germinal, embryonic,
and fetal)
• Explain how sexual differentiation occurs
• Describe the role the amniotic sac, amniotic fluid, and placenta play in the development
and delivery process
• Describe changes in the fetus throughout the pregnancy cycle
• Identify the different types of teratogens that can affect the developing fetus’ health as well
as the developmental stage where harm can occur
• Describe the impact of drugs that are the most likely to affect the healthy development of a
fetus (aspirin, thalidomide, hormones, vitamins, heroin, methadone, marijuana, alcohol,
cocaine, caffeine, and cigarettes)
• Describe the environmental effects on the fetus’ development such as prenatal exposure to
lead and/or the parents’ age at conception
Chapter Outline
The field of biology that studies heredity is called genetics.
I. The Influence of Heredity on Development
abnormalities
• Explain how Down syndrome occurs as well as its physical markers
• Describe how sex-linked chromosomal abnormalities occur
• Identify and compare the different sex-linked chromosomal disorders (Klinefelter
syndrome and Turner syndrome)
• Identify and compare disorders that have been contributed to genes (PKU, Huntington’s
disease, Sickle-Cell Anemia, Tay-Sachs disease, and Cystic Fibrosis)
• Identify and compare sex-linked genetic abnormalities (hemophilia, Duchenne muscular
dystrophy)
• Identify and explain different prenatal testing techniques used for various genetic disorders
• Describe how studies of kinship, adopted children, and identical (monozygotic) versus
fraternal (dizygotic) twins are used to explore the relative influences of nature (heredity)
versus nurture (environment)
• Explain the formation of eggs and sperm and where conception takes place
• To define the following terms: “ova,” “endometrium,” “sperm cells,” and “spontaneous
abortion”
• Discuss the causes of infertility and the methods that couples can use to conceive
• Discuss the benefits of adopting children
• Describe the preimplantation genetic diagnosis process
• Define and compare the different stages of prenatal development (germinal, embryonic,
and fetal)
• Explain how sexual differentiation occurs
• Describe the role the amniotic sac, amniotic fluid, and placenta play in the development
and delivery process
• Describe changes in the fetus throughout the pregnancy cycle
• Identify the different types of teratogens that can affect the developing fetus’ health as well
as the developmental stage where harm can occur
• Describe the impact of drugs that are the most likely to affect the healthy development of a
fetus (aspirin, thalidomide, hormones, vitamins, heroin, methadone, marijuana, alcohol,
cocaine, caffeine, and cigarettes)
• Describe the environmental effects on the fetus’ development such as prenatal exposure to
lead and/or the parents’ age at conception
Chapter Outline
The field of biology that studies heredity is called genetics.
I. The Influence of Heredity on Development
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3
• Genetic influences are fundamental in the transmission of physical traits, such as height,
hair texture, and eye color.
• Heredity appears to be a factor in almost all aspects of human behavior, personality, and
mental processes (Loehlin & Martin, 2018; Plomin & Haworth, 2009; Polderman et al.,
2015).
• Genetic factors are also involved in psychological problems such as schizophrenia,
depression, and dependence on nicotine, alcohol, and other substances (Leonardo & Hen,
2006; Lewis et al., 2013; Viding et al., 2013).
A. Chromosomes and Genes
• Chromosomes are rod-shaped structures found in cells.
• Genes are the biochemical materials that regulate the development of traits.
o Some traits, such as blood type, appear to be transmitted by a single pair of genes,
one of which is derived from each parent.
o Other traits are polygenic, that is, determined by several pairs of genes.
• Genes are segments of strands of deoxyribonucleic acid (DNA)—genetic material that
takes the form of a double helix composed of phosphates, sugars, and bases.
B. Mitosis and Meiosis
• There are two types of cell division: mitosis and meiosis.
• In mitosis, strands of DNA break apart, or “unzip.”
o The double helix then duplicates. The DNA forms two camps on either side of the
cell, and then the cell divides.
o Each incomplete rung combines with the appropriate “partner” (i.e., G and C, A
and T) to form a new complete ladder. The two resulting identical copies of the
DNA strand separate when the cell divides; each becomes a member of a newly
formed cell.
o As a result, the genetic code is identical in new cells unless mutations—sudden
variations in a heritable characteristic—occur through radiation or other
environmental influences.
• Sperms and ova (“egg cells”) are produced through meiosis, or reduction division.
o In meiosis, the 46 chromosomes within the cell nucleus first line up into 23 pairs.
The DNA ladders then unzip, leaving unpaired halves of chromosome.
o When the cell divides, one member of each pair goes to each newly formed cell.
Each new cell nucleus contains only 23 chromosomes, not 46. Each pair of
chromosomes splits so that one member of each pair moves to the new cell.
• When a sperm cell fertilizes an ovum, humans receive 23 chromosomes from their
father’s sperm cell and 23 from their mother’s ovum, and the combined chromosomes
• Genetic influences are fundamental in the transmission of physical traits, such as height,
hair texture, and eye color.
• Heredity appears to be a factor in almost all aspects of human behavior, personality, and
mental processes (Loehlin & Martin, 2018; Plomin & Haworth, 2009; Polderman et al.,
2015).
• Genetic factors are also involved in psychological problems such as schizophrenia,
depression, and dependence on nicotine, alcohol, and other substances (Leonardo & Hen,
2006; Lewis et al., 2013; Viding et al., 2013).
A. Chromosomes and Genes
• Chromosomes are rod-shaped structures found in cells.
• Genes are the biochemical materials that regulate the development of traits.
o Some traits, such as blood type, appear to be transmitted by a single pair of genes,
one of which is derived from each parent.
o Other traits are polygenic, that is, determined by several pairs of genes.
• Genes are segments of strands of deoxyribonucleic acid (DNA)—genetic material that
takes the form of a double helix composed of phosphates, sugars, and bases.
B. Mitosis and Meiosis
• There are two types of cell division: mitosis and meiosis.
• In mitosis, strands of DNA break apart, or “unzip.”
o The double helix then duplicates. The DNA forms two camps on either side of the
cell, and then the cell divides.
o Each incomplete rung combines with the appropriate “partner” (i.e., G and C, A
and T) to form a new complete ladder. The two resulting identical copies of the
DNA strand separate when the cell divides; each becomes a member of a newly
formed cell.
o As a result, the genetic code is identical in new cells unless mutations—sudden
variations in a heritable characteristic—occur through radiation or other
environmental influences.
• Sperms and ova (“egg cells”) are produced through meiosis, or reduction division.
o In meiosis, the 46 chromosomes within the cell nucleus first line up into 23 pairs.
The DNA ladders then unzip, leaving unpaired halves of chromosome.
o When the cell divides, one member of each pair goes to each newly formed cell.
Each new cell nucleus contains only 23 chromosomes, not 46. Each pair of
chromosomes splits so that one member of each pair moves to the new cell.
• When a sperm cell fertilizes an ovum, humans receive 23 chromosomes from their
father’s sperm cell and 23 from their mother’s ovum, and the combined chromosomes
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4
form 23 pairs.
o Twenty-two of the pairs are autosomes—pairs that look alike and possess genetic
information concerning the same set of traits.
o The 23rd pair are sex chromosomes, which look different from other
chromosomes and determine one’s sex.
C. Identical and Fraternal Twins
• Now and then, a zygote divides into two cells that separate so that each develops into an
individual with the same genetic makeup.
o These individuals are identical twins, or monozygotic (MZ) twins.
• If the woman produces two ova in the same month and they are each fertilized by
different sperm cells, they develop into fraternal twins, or dizygotic (DZ) twins.
• As women reach the end of their childbearing years, ovulation—releasing of an ovum
from an ovary—becomes less regular, resulting in a number of months when more than
one ovum is released.
D. Dominant and Recessive Traits
• Each member of a pair of genes is termed as an allele.
• When both of the allele for a trait, such as hair color, are the same, the person is said to
be homozygous for that trait.
• When the alleles for a trait differ, the person is heterozygous for that trait.
• When the effects of both alleles are shown, there is said to be incomplete dominance or
codominance.
• When a dominant allele is paired with a recessive allele, the trait determined by the
dominant allele appears in the offspring.
o Dominant trait is a trait that is expressed.
o Recessive trait is a trait that is not expressed when the gene or genes involved
have been paired with dominant genes.
• People who bear one dominant gene and one recessive gene for a trait are said to be
carriers of the recessive gene.
E. Chromosomal and Genetic Abnormalities
• Chromosomal or genetic abnormalities can cause health problems.
o Some chromosomal disorders reflect abnormalities in the 22 pairs of
autosomes (such as Down syndrome); others reflect abnormalities in the sex
chromosomes (e.g., XYY syndrome).
o Some genetic abnormalities, such as cystic fibrosis, are caused by a single pair
form 23 pairs.
o Twenty-two of the pairs are autosomes—pairs that look alike and possess genetic
information concerning the same set of traits.
o The 23rd pair are sex chromosomes, which look different from other
chromosomes and determine one’s sex.
C. Identical and Fraternal Twins
• Now and then, a zygote divides into two cells that separate so that each develops into an
individual with the same genetic makeup.
o These individuals are identical twins, or monozygotic (MZ) twins.
• If the woman produces two ova in the same month and they are each fertilized by
different sperm cells, they develop into fraternal twins, or dizygotic (DZ) twins.
• As women reach the end of their childbearing years, ovulation—releasing of an ovum
from an ovary—becomes less regular, resulting in a number of months when more than
one ovum is released.
D. Dominant and Recessive Traits
• Each member of a pair of genes is termed as an allele.
• When both of the allele for a trait, such as hair color, are the same, the person is said to
be homozygous for that trait.
• When the alleles for a trait differ, the person is heterozygous for that trait.
• When the effects of both alleles are shown, there is said to be incomplete dominance or
codominance.
• When a dominant allele is paired with a recessive allele, the trait determined by the
dominant allele appears in the offspring.
o Dominant trait is a trait that is expressed.
o Recessive trait is a trait that is not expressed when the gene or genes involved
have been paired with dominant genes.
• People who bear one dominant gene and one recessive gene for a trait are said to be
carriers of the recessive gene.
E. Chromosomal and Genetic Abnormalities
• Chromosomal or genetic abnormalities can cause health problems.
o Some chromosomal disorders reflect abnormalities in the 22 pairs of
autosomes (such as Down syndrome); others reflect abnormalities in the sex
chromosomes (e.g., XYY syndrome).
o Some genetic abnormalities, such as cystic fibrosis, are caused by a single pair
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5
of genes; others are caused by combinations of genes.
o Diabetes mellitus, epilepsy, and peptic ulcers are multifactorial problems;
they reflect both a genetic predisposition and environmental contributors.
F. Chromosomal Abnormalities
Down syndrome
• Down syndrome is usually caused by an extra chromosome on the 21st pair,
resulting in 47 chromosomes.
• People with Down syndrome have characteristic features that include a rounded face,
a protruding tongue, a broad, flat nose, and a sloping fold of skin over the inner
corners of the eyes.
Sex-Linked Chromosomal Abnormalities
• A number of disorders stem from an abnormal number of sex chromosomes and are
therefore called sex-linked chromosomal abnormalities.
o Most individuals with an abnormal number of sex chromosomes are infertile.
• Approximately one male in 500 has Klinefelter syndrome, which is caused by an
extra X sex chromosome (an XXY sex chromosomal pattern).
o XXY males produce less of the male sex hormone testosterone than normal
males.
• Approximately one girl in 2,500 has a single X sex chromosome and as a result
develops Turner syndrome.
o The external genitals of such girls are normal, but their ovaries are poorly
developed and they produce little estrogen—the female sex hormone produced
mainly by the ovaries.
• Approximately one girl in 1,000 has an XXX sex chromosomal structure, called
Triple X syndrome.
o Such girls are normal in appearance but tend to show lower-than-average
language skills and poorer memory for recent events.
G. Genetic Abnormalities
Phenylketonuria
• The enzyme disorder phenylketonuria (PKU) is transmitted by a recessive gene and
affects about one child in 8,000.
• Children with PKU cannot metabolize an amino acid called phenylalanine, so it
of genes; others are caused by combinations of genes.
o Diabetes mellitus, epilepsy, and peptic ulcers are multifactorial problems;
they reflect both a genetic predisposition and environmental contributors.
F. Chromosomal Abnormalities
Down syndrome
• Down syndrome is usually caused by an extra chromosome on the 21st pair,
resulting in 47 chromosomes.
• People with Down syndrome have characteristic features that include a rounded face,
a protruding tongue, a broad, flat nose, and a sloping fold of skin over the inner
corners of the eyes.
Sex-Linked Chromosomal Abnormalities
• A number of disorders stem from an abnormal number of sex chromosomes and are
therefore called sex-linked chromosomal abnormalities.
o Most individuals with an abnormal number of sex chromosomes are infertile.
• Approximately one male in 500 has Klinefelter syndrome, which is caused by an
extra X sex chromosome (an XXY sex chromosomal pattern).
o XXY males produce less of the male sex hormone testosterone than normal
males.
• Approximately one girl in 2,500 has a single X sex chromosome and as a result
develops Turner syndrome.
o The external genitals of such girls are normal, but their ovaries are poorly
developed and they produce little estrogen—the female sex hormone produced
mainly by the ovaries.
• Approximately one girl in 1,000 has an XXX sex chromosomal structure, called
Triple X syndrome.
o Such girls are normal in appearance but tend to show lower-than-average
language skills and poorer memory for recent events.
G. Genetic Abnormalities
Phenylketonuria
• The enzyme disorder phenylketonuria (PKU) is transmitted by a recessive gene and
affects about one child in 8,000.
• Children with PKU cannot metabolize an amino acid called phenylalanine, so it
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6
builds up in their bodies and impairs the functioning of the central nervous system,
resulting in mental retardation, psychological disorders, and physical problems.
Huntington’s Disease
• Huntington’s disease (HD) is a fatal, progressive degenerative disorder and a
dominant trait affecting approximately one American in 18,000.
• Physical symptoms include uncontrollable muscle movements.
• Psychological symptoms include loss of intellectual functioning and personality
change.
Sickle-Cell Anemia
• Sickle-cell anemia is caused by a recessive gene.
• In sickle-cell anemia, red blood cells take on the shape of a sickle and clump
together, obstructing small blood vessels and decreasing the oxygen supply.
Tay-Sachs disease
• Tay-Sachs disease is also caused by a recessive gene.
• It causes the central nervous system to degenerate, resulting in death.
Cystic Fibrosis
• Cystic fibrosis, also caused by a recessive gene, is the most common fatal hereditary
disease among European Americans.
• Children with the disease suffer from excessive production of thick mucus that clogs
the pancreas and lungs.
Sex-Linked Genetic Abnormalities
• Some genetic defects, such as hemophilia—a genetic disorder in which blood does
not clot properly—are carried on only the X sex chromosome.
o For this reason, they are referred to as sex-linked genetic abnormalities.
• One form of muscular dystrophy, Duchenne muscular dystrophy, is sex linked.
o Muscular dystrophy is characterized by a weakening of the muscles, which can
lead to wasting away, inability to walk, and sometimes death.
H. Genetic Counseling and Prenatal Testing
builds up in their bodies and impairs the functioning of the central nervous system,
resulting in mental retardation, psychological disorders, and physical problems.
Huntington’s Disease
• Huntington’s disease (HD) is a fatal, progressive degenerative disorder and a
dominant trait affecting approximately one American in 18,000.
• Physical symptoms include uncontrollable muscle movements.
• Psychological symptoms include loss of intellectual functioning and personality
change.
Sickle-Cell Anemia
• Sickle-cell anemia is caused by a recessive gene.
• In sickle-cell anemia, red blood cells take on the shape of a sickle and clump
together, obstructing small blood vessels and decreasing the oxygen supply.
Tay-Sachs disease
• Tay-Sachs disease is also caused by a recessive gene.
• It causes the central nervous system to degenerate, resulting in death.
Cystic Fibrosis
• Cystic fibrosis, also caused by a recessive gene, is the most common fatal hereditary
disease among European Americans.
• Children with the disease suffer from excessive production of thick mucus that clogs
the pancreas and lungs.
Sex-Linked Genetic Abnormalities
• Some genetic defects, such as hemophilia—a genetic disorder in which blood does
not clot properly—are carried on only the X sex chromosome.
o For this reason, they are referred to as sex-linked genetic abnormalities.
• One form of muscular dystrophy, Duchenne muscular dystrophy, is sex linked.
o Muscular dystrophy is characterized by a weakening of the muscles, which can
lead to wasting away, inability to walk, and sometimes death.
H. Genetic Counseling and Prenatal Testing
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7
• Genetic counselors compile information about a couple’s genetic heritage to explore
whether their children might develop genetic abnormalities.
• Prenatal—before birth—testing can indicate whether an embryo or fetus is carrying
genetic abnormalities.
• Although amniocentesis and chorionic villus sampling is discussed next, it should be
noted that their use is declining due to blood testing and ultrasounds becoming more
sophisticated and providing a clearer picture early on in the pregnancy.
Amniocentesis
• Amniocentesis is usually performed on the mother at 14-16 weeks after conception,
although many physicians now perform the procedure earlier.
o In this fetal-screening method, the health professional uses a syringe (needle)
to withdraw fluid from the amniotic sac.
o The fluid contains cells that are sloughed off by the fetus.
o The cells are separated from the amniotic fluid, grown in a culture, and then
examined microscopically for genetic and chromosomal abnormalities.
• Amniocentesis carries some risk of miscarriage—expulsion of an embryo or fetus
before it can sustain life on its own, most often due to defective development—
although the extent of the risk is unclear.
Chorionic Villus Sampling
• Chorionic villus sampling (CVS) is similar to amniocentesis but is carried out
between the 9th and 12th week of pregnancy.
o A small syringe is inserted through the vagina into the uterus and sucks out
some threadlike projections (villi) from the outer membrane that envelops the
amniotic sac and fetus.
• CVS has not been used as frequently as amniocentesis because CVS carries a slightly
greater risk of miscarriage.
Ultrasound
• Health professionals use sound waves that are too high in frequency to be heard by
the human ear—ultrasound—to obtain information about the fetus.
o These waves are reflected by the fetus, and a computer uses the information to
generate a picture of the fetus. The picture is termed a sonogram.
Blood Tests
• Genetic counselors compile information about a couple’s genetic heritage to explore
whether their children might develop genetic abnormalities.
• Prenatal—before birth—testing can indicate whether an embryo or fetus is carrying
genetic abnormalities.
• Although amniocentesis and chorionic villus sampling is discussed next, it should be
noted that their use is declining due to blood testing and ultrasounds becoming more
sophisticated and providing a clearer picture early on in the pregnancy.
Amniocentesis
• Amniocentesis is usually performed on the mother at 14-16 weeks after conception,
although many physicians now perform the procedure earlier.
o In this fetal-screening method, the health professional uses a syringe (needle)
to withdraw fluid from the amniotic sac.
o The fluid contains cells that are sloughed off by the fetus.
o The cells are separated from the amniotic fluid, grown in a culture, and then
examined microscopically for genetic and chromosomal abnormalities.
• Amniocentesis carries some risk of miscarriage—expulsion of an embryo or fetus
before it can sustain life on its own, most often due to defective development—
although the extent of the risk is unclear.
Chorionic Villus Sampling
• Chorionic villus sampling (CVS) is similar to amniocentesis but is carried out
between the 9th and 12th week of pregnancy.
o A small syringe is inserted through the vagina into the uterus and sucks out
some threadlike projections (villi) from the outer membrane that envelops the
amniotic sac and fetus.
• CVS has not been used as frequently as amniocentesis because CVS carries a slightly
greater risk of miscarriage.
Ultrasound
• Health professionals use sound waves that are too high in frequency to be heard by
the human ear—ultrasound—to obtain information about the fetus.
o These waves are reflected by the fetus, and a computer uses the information to
generate a picture of the fetus. The picture is termed a sonogram.
Blood Tests
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