Susan beal hypothesized that _____ played a role in sids deaths.

The Developing Person

Through Childhood and Adolescence

ELEVENTH EDITION

The Developing Person

Through Childhood and Adolescence

Kathleen Stassen Berger Bronx Community College City University of New York

Vice President, Social Sciences and High School: Charles Linsmeier Director of Content and Assessment, Social Sciences: Shani Fisher Executive Program Manager: Christine Cardone Developmental Editor: Andrea Musick Page Assistant Editor: Melissa Rostek Executive Marketing Manager: Katherine Nurre Marketing Assistant: Morgan Ratner Director of Media Editorial, Social Sciences: Noel Hohnstine Senior Media Editor: Laura Burden Assistant Media Editor: Nik Toner Director, Content Management Enhancement: Tracey Kuehn Managing Editor: Lisa Kinne Senior Content Project Manager: Peter Jacoby Senior Project Manager: Andrea Stefanowicz, Lumina Datamatics, Inc. Media Producer: Joseph Tomasso Senior Workflow Supervisor: Susan Wein Photo Editor: Sheena Goldstein Photo Researcher: Candice Cheesman Director of Design, Content Management: Diana Blume Cover and Interior Design: Lumina Datamatics, Inc. Art Manager: Matthew McAdams Illustrations: Lumina Datamatics, Charles Yuen Composition: Lumina Datamatics, Inc. Cover Photograph: Images By Tang Ming Tung/DigitalVision/Getty Images

Library of Congress Control Number: 2017936099 ISBN-13: 978-1-319-14624-5 (EPUB)

Copyright © 2018, 2015, 2012, 2009 Worth Publishers All rights reserved.

WORTH PUBLISHERS One New York Plaza Suite 4500 New York, NY 10004-1562 www.macmillanlearning.com

http://www.macmillanlearning.com
ABOUT THE AUTHOR

Kathleen Stassen Berger received her undergraduate education at Stanford University and Radcliffe College, and then she earned an MAT from Harvard University and an M.S. and Ph.D. from Yeshiva University. Her broad experience as an educator includes directing a preschool, serving as chair of philosophy at the United Nations International School, and teaching child and adolescent development at Fordham University graduate school, Montclair State University, and Quinnipiac University. She also taught social psychology to inmates at Sing Sing Prison who were earning paralegal degrees.

Currently, Berger is a professor at Bronx Community College of the City University of New York, as she has been for most of her professional career. She began there as an adjunct in English and for the past decades has been a full professor in the Social Sciences Department, which includes psychology, sociology, economics, anthropology, political science, and human services. She has taught introduction to psychology, child and adolescent development, adulthood and aging, social psychology, abnormal psychology, and human motivation. Her students—from diverse ethnic, economic, and educational backgrounds, of many ages, ambitions, and interests—honor her with the highest teaching evaluations.

Berger is also the author of Invitation to the Life Span and The Developing Person Through the Life Span. Her developmental texts are used at more than 700 colleges and universities worldwide and are available in Spanish, French, Italian, and Portuguese as well as English. Her research interests include adolescent identity, immigration, bullying, and grandparents, and she has published articles on developmental topics in the Wiley Encyclopedia of Psychology, Developmental Review, and in publications of the American Association for Higher Education and the National Education Association for Higher Education. She continues teaching and learning from her students as well as from her four daughters and three grandsons.

BRIEF CONTENTS

Preface

PART I The Beginnings CHAPTER 1 The Science of Human Development

CHAPTER 2 Theories

CHAPTER 3 The New Genetics

CHAPTER 4 Prenatal Development and Birth

PART II The First Two Years CHAPTER 5 The First Two Years: Biosocial Development

CHAPTER 6 The First Two Years: Cognitive Development

CHAPTER 7 The First Two Years: Psychosocial Development

PART III Early Childhood CHAPTER 8 Early Childhood: Biosocial Development

CHAPTER 9 Early Childhood: Cognitive Development

CHAPTER 10 Early Childhood: Psychosocial Development

PART IV Middle Childhood CHAPTER 11 Middle Childhood: Biosocial Development

CHAPTER 12 Middle Childhood: Cognitive Development

CHAPTER 13 Middle Childhood: Psychosocial Development

PART V Adolescence CHAPTER 14 Adolescence: Biosocial Development

CHAPTER 15 Adolescence: Cognitive Development

CHAPTER 16 Adolescence: Psychosocial Development

EPILOGUE Emerging Adulthood

APPENDIX More About Research Methods

Glossary References Name Index Subject Index

CONTENTS Preface

PART I

The Beginnings

Chapter 1 The Science of Human Development Understanding How and Why

The Scientific Method A VIEW FROM SCIENCE: Overweight Children and Adult Health The Nature–Nurture Controversy

The Life-Span Perspective Development Is Multidirectional

Development Is Multicontextual INSIDE THE BRAIN: Thinking About Marijuana Development Is Multicultural Development Is Multidisciplinary Development Is Plastic

A CASE TO STUDY: David Designing Science

Observation The Experiment The Survey Studying Development over the Life Span

Cautions and Challenges from Science Correlation and Causation Quantity and Quality Ethics

Chapter 2 Theories What Theories Do

Questions and Answers Past and Future

Grand Theories Psychoanalytic Theory: Freud and Erikson Behaviorism: Conditioning and Learning Cognitive Theory: Piaget and Information Processing INSIDE THE BRAIN: Measuring Mental Activity

Newer Theories Sociocultural Theory: Vygotsky and Beyond Evolutionary Theory OPPOSING PERSPECTIVES: Toilet Training—How and When?

What Theories Contribute

Chapter 3 The New Genetics The Genetic Code

46 to 21,000 to 3 Billion Same and Different Matching Genes and Chromosomes OPPOSING PERSPECTIVES: Too Many Boys?

New Cells, New People Cells and Identity Twins and More

From Genotype to Phenotype Many Factors Gene–Gene Interactions Nature and Nurture Practical Applications

Chromosomal and Genetic Problems Spontaneous Mutations Not Exactly 46 Gene Disorders Genetic Counseling and Testing

A CASE TO STUDY: Raising Healthy Children

Chapter 4 Prenatal Development and Birth Prenatal Development

Germinal: The First 14 Days Embryo: From the Third Week Through the Eighth Week Fetus: From the Ninth Week Until Birth INSIDE THE BRAIN: Neuronal Birth and Death

Birth The Newborn’s First Minutes Medical Assistance

Problems and Solutions Harmful Substances Applying the Research A VIEW FROM SCIENCE: What Is Safe? Prenatal Diagnosis Low Birthweight: Causes and Consequences OPPOSING PERSPECTIVES: “What Do People Live to Do?” Complications During Birth

The New Family The Newborn New Mothers

New Fathers Parental Alliance Family Bonding

PART II

The First Two Years

Chapter 5 The First Two Years: Biosocial Development Body Changes

Body Size Sleep Brain Development INSIDE THE BRAIN: Neuroscience Vocabulary Harming the Infant Body and Brain A VIEW FROM SCIENCE: Face Recognition

Perceiving and Moving The Senses Motor Skills Cultural Variations

Surviving in Good Health Better Days Ahead A CASE TO STUDY: Scientist at Work Immunization Nutrition

Chapter 6 The First Two Years: Cognitive Development Sensorimotor Intelligence

Stages One and Two: Primary Circular Reactions Stages Three and Four: Secondary Circular Reactions Stages Five and Six: Tertiary Circular Reactions A VIEW FROM SCIENCE: Object Permanence

Information Processing Affordances Memory

Language: What Develops in the First Two Years? The Universal Sequence INSIDE THE BRAIN: Understanding Speech Cultural Differences Theories of Language Learning

OPPOSING PERSPECTIVES: Language and Video

Chapter 7 The First Two Years: Psychosocial Development Emotional Development

Early Emotions Toddlers’ Emotions Temperament INSIDE THE BRAIN: Expressing Emotions

The Development of Social Bonds Synchrony Attachment Insecure Attachment and the Social Setting A CASE TO STUDY: Can We Bear This Commitment? Social Referencing Fathers as Social Partners

Theories of Infant Psychosocial Development Psychoanalytic Theory Behaviorism Cognitive Theory Evolutionary Theory Sociocultural Theory Conclusion

PART III

Early Childhood

Chapter 8 Early Childhood: Biosocial Development

Body Changes Growth Patterns Nutrition Brain Growth INSIDE THE BRAIN: Connected Hemispheres

Advancing Motor Skills Gross Motor Skills A VIEW FROM SCIENCE: Eliminating Lead Fine Motor Skills

Injuries and Abuse Avoidable Injury A CASE TO STUDY: “My Baby Swallowed Poison” Prevention

Child Maltreatment Definitions and Statistics Frequency of Maltreatment Consequences of Maltreatment Preventing Maltreatment

Chapter 9 Early Childhood: Cognitive Development Thinking During Early Childhood

Piaget: Preoperational Thought A CASE TO STUDY: Stones in the Belly Vygotsky: Social Learning Children’s Theories

Brain and Context Language Learning

A Sensitive Time The Vocabulary Explosion Acquiring Grammar Learning Two Languages

Early-Childhood Schooling Homes and Schools Child-Centered Programs Teacher-Directed Programs Intervention Programs Long-Term Gains from Intensive Programs

Chapter 10 Early Childhood: Psychosocial Development Emotional Development

Initiative Versus Guilt Motivation

Play Playmates Active Play Learning Emotional Regulation

Challenges for Caregivers Styles of Caregiving A VIEW FROM SCIENCE: Culture and Parenting Style Discipline

OPPOSING PERSPECTIVES: Is Spanking OK? Becoming Boys or Girls: Sex and Gender A CASE TO STUDY: The Berger Daughters What Is Best?

PART IV

Middle Childhood

Chapter 11 Middle Childhood: Biosocial Development A Healthy Time

Slower Growth, Greater Strength Physical Activity Health Problems in Middle Childhood A VIEW FROM SCIENCE: What Causes Childhood Obesity?

Children with Special Brains and Bodies Measuring the Mind Special Needs in Middle Childhood Specific Learning Disorders OPPOSING PERSPECTIVES: Drug Treatment for ADHD and Other Disorders

Special Education A CASE TO STUDY: Unexpected and Odd Labels, Laws, and Learning Early Intervention Gifted and Talented

Chapter 12 Middle Childhood: Cognitive Development Building on Theory

Piaget and Concrete Thought Vygotsky and Culture A CASE TO STUDY: Is She Going to Die? Information Processing INSIDE THE BRAIN: Coordination and Capacity Memory Control Processes

Language Vocabulary Speaking Two Languages Differences in Language Learning OPPOSING PERSPECTIVES: Happiness or High Grades?

Teaching and Learning International Schooling Schooling in the United States Choices and Complications

Chapter 13 Middle Childhood: Psychosocial Development The Nature of the Child

Self-Concept OPPOSING PERSPECTIVES: Protect or Puncture Self-Esteem? Resilience and Stress

Families and Children Shared and Nonshared Environments Family Structure and Family Function A VIEW FROM SCIENCE: “I Always Dressed One in Blue Stuff . . .” Connecting Structure and Function Family Trouble

The Peer Group The Culture of Children A CASE TO STUDY: Ignorance All Around

Children’s Moral Values Moral Reasoning What Children Value

PART V

Adolescence

Chapter 14 Adolescence: Biosocial Development Puberty Begins

Unseen Beginnings Brain Growth When Will Puberty Begin? INSIDE THE BRAIN: Lopsided Growth A VIEW FROM SCIENCE: Stress and Puberty Too Early, Too Late

Growth and Nutrition Growing Bigger and Stronger Diet Deficiencies Eating Disorders

Sexual Maturation Sexual Characteristics Sexual Activity Sexual Problems in Adolescence

Chapter 15 Adolescence: Cognitive Development Logic and Self

Egocentrism Formal Operational Thought Two Modes of Thinking A CASE TO STUDY: Biting the Policeman INSIDE THE BRAIN: Impulses, Rewards, and Reflection

Digital Natives Technology and Cognition Sexual Abuse?

Addiction Cyber Danger

Secondary Education Definitions and Facts Middle School High School OPPOSING PERSPECTIVES: Testing Variability

Chapter 16 Adolescence: Psychosocial Development Identity

Not Yet Achieved Four Arenas of Identity Formation

Relationships with Adults A VIEW FROM SCIENCE: Teenagers, Genes, and Drug Use Parents

Peer Power Peer Pressure A CASE TO STUDY: The Naiveté of Your Author Romance Sex Education

Sadness and Anger Depression Delinquency and Defiance

Drug Use and Abuse

Variations in Drug Use OPPOSING PERSPECTIVES: E-Cigarettes: Path to Addiction or Healthy Choice?

Harm from Drugs Preventing Drug Abuse: What Works?

Epilogue Emerging Adulthood Biosocial Development

Strong and Active Bodies Taking Risks

Cognitive Development Countering Stereotypes Cognitive Growth and Higher Education

Psychosocial Development Identity Achievement Intimacy Needs Concluding Questions and Hopes

Appendix More About Research Methods Make It Personal Read the Research

Professional Journals and Books The Internet

Additional Terms and Concepts Who Participates? Research and Design Reporting Results

PREFACE

If human development were simple, universal, and unchanging, there would be no need for a new edition of this textbook. Nor would anyone need to learn anything about human growth. But human development is complex, varied, and never the same.

This is evident to me in small ways as well as large ones. Yesterday, I made the mistake of taking two of my grandsons, aged 6 and 7, to the grocery store, asking them what they wanted for dinner. I immediately rejected their first suggestions—doughnuts or store-made sandwiches. But we lingered over the meat counter. Asa wanted hot dogs and Caleb wanted chicken. Neither would concede.

At least one universal is apparent in this anecdote: Grandmothers seek to nourish grandchildren. But complexity and variability were evident in two stubborn cousins and one confused grandmother.

This small incident is not unlike the headlines in today’s newspaper. Indeed, other developmental questions seem more urgent now, interweaving what is universally true about humans with what is new and immediate, balancing them in order to move forward with our public and personal lives. I found a compromise for dinner—chicken hot dogs, which both boys ate, with whole wheat bread and lots of ketchup. I do not know the solutions to public dilemmas such as climate change, immigration, gun violence, and systemic racism, but I believe that a deeper and more accurate understanding of human development might help.

That is why I wrote this eleventh edition, which presents both the enduring and the current findings from the study of child and adolescent development. Some of those findings have been recognized for decades, even centuries, and some are new, as thousands of scientists study how humans grow and change with new circumstances. I hope they will help us with the public and private aspects of our lives.

What’s New in the Eleventh Edition? New Material Every year, scientists discover and explain more concepts and research. The best of these are integrated into the text, with hundreds of new references on many topics, including epigenetics at conception, prenatal protections, infant nutrition, autism spectrum disorder, attachment, high- stakes testing, drug addiction and opioid-related deaths, sex education, and diversity of all kinds —ethnic, economic, gender, and cultural. Cognizant of the interdisciplinary nature of human development, I include recent research in biology, sociology, education, anthropology, political science, and more—as well as my home discipline, psychology.

What Can You Learn? Scientists first establish what is, and then they try to change it. In one recent experiment, Deb Kelemen (shown here) established that few children under age 12 understand a central concept of evolution (natural selection). Then she showed an experimental group a picture book illustrating the idea. Success! The independent variable (the book) affected the dependent variable (the children’s ideas), which confirmed Kelemen’s hypothesis: Children can understand natural selection if instruction is tailored to their ability.

Genetics and social contexts are noted throughout. The interaction of nature and nurture is discussed in many chapters, because neuroscience relates to every aspect of life. Among the many topics described with new research are the variations, benefits, and hazards of breast- feeding, infant day care, preschool education, single parenthood, exercise, vaccination, same-sex marriage—always noting differences, deficits, and resilience.

No paragraph in this edition is exactly what it was in the tenth edition. To help professors who taught with the earlier texts, or students who have friends who took the course a few years ago, here are some highlights of the updates:

Is She Awake? This 36-year-old mother in Hong Kong put her 7-month-old baby on her back, protecting her from SIDS as the Chinese have done for centuries. However, the soft pillow and comforter are hazards. Will she carry the baby to a safe place before she falls asleep?

Updated examples illustrating replication, race and ethnicity, and cross-sequential study

(Chapter 1). New feature on childhood obesity illustrating the scientific method (Chapter 1). New feature on marijuana use and sensitive periods (Chapter 1). Expanded discussion and new examples of what theories do (Chapter 2). New example and figure on opioid-related deaths illustrating classical conditioning (Chapter 2). Descriptions of newer brain imaging techniques such as DTI (diffusion tensor imaging) (Chapter 2). Grandmother hypothesis added to the discussion of evolutionary theory (Chapter 2). New coverage on the impact of the microbiome (Chapter 3). Updated material on stem cells and the use of CRISPR (Chapter 3). New feature on genetic counseling (Chapter 3). New feature on neurogenesis in the developing fetus (Chapter 4). Updated coverage and data on cesarean sections, the utilization of midwives, and alternatives to hospital birth (Chapter 4). Added discussion of teratogens, including recent research and data on Zika virus (Chapter 4). New research and data on international trends in low birthweight (Chapter 4). Updated coverage and research examples of infant sleep, bed-sharing, and co-sleeping (Chapter 5). New feature explaining neuroscience terms and brain structures (Chapter 5). New research on newborn vision and experience of pain (Chapter 5). Added coverage of motor-skill development, including walking (Chapter 5). New research on memory in infancy (Chapter 6). New coverage of bilingualism in babies (Chapter 6). Added discussion of attachment and the work of Bowlby and Ainsworth (Chapter 7). New features on emotional expression and adoptive parents’ attachment to their children (Chapter 7). Expanded coverage and research on infant day care, including new data on international trends in paid family leave (Chapter 7). Updated research on childhood obesity and nutrition (Chapter 8). Added discussion and research on childhood allergies (Chapter 8). New research on dangers of environmental pollutants in early childhood (Chapter 8). New research examples in discussion of young children’s logic (Chapter 9). Expanded discussion and new research on STEM learning, educational software use, and bilingualism in early childhood (Chapter 9). New research on brain plasticity and emotional regulation (Chapter 10). New coverage and data on screen time (Chapter 10). New research on gender development and gender differences (Chapter 10). Added discussion of embodied cognition and the importance of physical activity for overall health (Chapter 11). Added coverage on Sternberg, Gardner, and multiple intelligences (Chapter 11).

Updated coverage of childhood psychopathology, including ADHD, autism spectrum disorder, and specific learning disorders, and special education (Chapter 11). New feature on cognition in middle childhood (Chapter 12). Added discussion of Vygotsky and the role of instruction (Chapter 12). New discussion of the U.S. Common Core standards and of Finland’s recent education reform (Chapter 12). Added discussion and research on social comparison in middle childhood (Chapter 13). New U.S. and international research on various family structures (Chapter 13). New feature and research on bullying (Chapter 13). Added discussion of the benefits of psychotherapy for emotional problems during adolescence (Chapter 14). New coverage and research on executive function (Chapter 14). New research on eating disorders and sexual activity during adolescence (Chapter 14). Added discussion and research on advances in cognition during adolescence (Chapter 15). Updated coverage of media use among adolescents (Chapter 15). New research on adolescents’ experience of middle school (Chapter 15). Updated coverage of ethnic and gender development, as well as sexual orientation (Chapter 16). Updated coverage of teenage drug use, including e-cigarettes (Chapter 16). More coverage on exercise and new data on family-planning trends worldwide (Epilogue). Updated material on college completion and debt, including a new infographic (Epilogue). Updated material and new research on dating, cohabitation, and romance in emerging adults (Epilogue).

Universal Morality Remarkable? Not really. By the end of middle childhood, many children are eager to express their moral convictions, especially with a friend. Chaim Ifrah and Shai Reef believe that welcoming refugees is part of being a patriotic Canadian and a devout Jew, so they brought a welcoming sign to the Toronto airport where Syrian refugees (mostly Muslim) will soon deplane.

New Inside the Brain Feature

Since new discoveries abound almost daily in the field of neuroscience, I have added Inside the Brain features to several chapters, exploring topics such as the intricacies of prenatal and infant brain development, brain specialization and speech development, and brain maturation and emotional development.

New and Updated Coverage of Neuroscience Inclusion of neuroscience is a familiar feature of this book. In addition to the new Inside the Brain features, I include the latest, cutting-edge research on the brain in virtually every chapter, often enhancing it with charts, figures, and photos to help students understand the brain’s inner workings. A list highlighting this material is available at macmillanlearning.com.

New Developing Lives Developing Lives is a robust and sophisticated interactive experience in which each student “raises” a virtual child from sperm-and-egg to teenager—fully integrated into LaunchPad. With Developing Lives, each student creates a personal profile, selects a virtual partner (or chooses to be a single parent), and marks the arrival of their newborn (represented by a unique avatar based on the parents’ characteristics). As the child grows, the student responds to events both planned and unforeseen, making important decisions (nutrition choices, doctor visits, sleeping location) and facing uncertain moments (illness, divorce, a new baby), with each choice affecting how the child grows. Throughout, Developing Lives deepens each student’s attachment and understanding of key concepts in the field with immediate, customized feedback based on child development research. It integrates more than 200 videos and animations and includes quizzes and essay questions that are easy to assign and assess.

New Integration with LaunchPad Throughout the book, the margins include LaunchPad call-outs to online videos about people in a particular context or key scientists who might become role models. For example, Susan Beal, the Australian scientist who revolutionized our understanding of SIDS (sudden infant death

http://www.macmillanlearning.com
syndrome) and infant sleep is shown. The video demonstrates that she is not an aloof expert, but a wife and mother, like many students and their relatives. Application to Developing Lives (described above) and Data Connections activities (described below) are also highlighted for the reader.

Renewed Emphasis on Critical Thinking and Application in the Pedagogical Program We all need to be critical thinkers. Virtually every page of this book presents questions as well as facts. A new marginal feature, Think Critically, encourages student reflection and analysis. There are no pat answers to these questions: They could be used to start a class discussion or begin a long essay.

Every chapter begins with a few What Will You Know? questions, one for each major heading. Of course, much of what readers will learn will be reflected in new attitudes and perspectives— hard to quantify. But these What Will You Know? questions are intended to be provocative and to pose issues that the students will remember for decades.

In addition, after every major section, What Have You Learned? questions appear. They are designed to help students review what they have just read, a pedagogical technique proven to help retention. Ideally, students will answer these learning objective questions in sentences, with specifics that demonstrate knowledge. Some items on the new lists are straightforward, requiring only close attention to the chapter content. Others require comparisons, implications, or evaluations.

Key terms are indicated with bold print and are defined in the margins as well as in the glossary, because expanded vocabulary aids expanded understanding. To help students become better observers, occasional Observation Quizzes accompany a photo or figure. And, since many students reading this book are preparing to be teachers, health care professionals, police officers,

or parents, every chapter contains Especially For questions that encourage students to apply important developmental concepts just as experts in the field do.

As a professor myself, I continue to seek ways to deepen knowledge. Cognitive psychology and research on pedagogy finds that vocabulary, specific applications details, and critical thinking are all part of learning. These features are designed to foster all four.

Updated Features Online Data Connections Activities Understanding how scientists use data helps students realize that the study of human development is much more than personal experience and common sense. Evidence sometimes contradicts myths and assumptions, and sometimes it confirms them. This edition continues to offer interactive activities—many of which have been updated with the latest available data—to allow students to interpret data on topics ranging from infant breast-feeding to adolescent risk- taking.

For example, students discover how U.S. poverty rates are worse for children than for adults, data that may be surprising. These interactive activities advance active thinking, deepening their understanding of the need for data. Instructors can assign these activities in the online LaunchPad that accompanies this book.

Opposing Perspectives, A View from Science, and A Case to Study Special topics and new research abound in childhood and adolescent development. This edition

of The Developing Person Through Childhood and Adolescence includes boxed features in every chapter. Opposing Perspectives focuses on controversial topics—from prenatal sex selection to e-cigarettes. Information and opinions on both sides of each issue are presented, so students can weigh evidence, assess arguments, and reach their own conclusions while appreciating that an opposite conclusion also has merit. A View from Science explains research in more detail, illustrating the benefits of the scientific method. A Case to Study focuses on particular individuals, helping students to recognize the personal implications of what they learn.

Infographics Information is sometimes better understood visually and graphically. Carefully chosen, updated photos and figures appear on almost every page, with captions that explain and increase knowledge. In addition, every chapter includes a full-page, graphical depiction.

These infographics explain key concepts, from brain development to school attendance rates, often with data that encourage students to think of other nations, other cultures, other times. My two awesome editors and I have worked closely with noted designer Charles Yuen to create these infographics, hoping they reinforce key ideas.

Child Development and Nursing Career Correlation Guides Many students taking this course will become nurses or early-childhood educators. This book and accompanying testing material are fully correlated to the NAEYC (National Association for the Education of Young Children) career preparation goals and the NCLEX (nursing) licensure exam. These two supplements are available in LaunchPad.

Ongoing Features Writing That Communicates the Excitement and Challenge of the Field Writing about the science of human development should be lively, just as people are. Each sentence conveys attitude as well as content. Chapter-opening vignettes describe real-life situations. Examples and clear explanations abound, helping students connect theory, research, and experiences.

Coverage of Diversity Cross-cultural, international, multiethnic, sexual orientation, poverty, age, family structure, gender—all these words and ideas are vital to appreciating how children develop. Research uncovers surprising similarities and notable differences: All people have much in common, yet each human is unique. From the discussion of social contexts in Chapter 1 to the coverage of cultural differences among emerging adults in the Epilogue, each chapter explains that no one is average; each of us is diverse.

New research on family structures, immigrants, bilingualism, and ethnic differences in health are among the many topics that illustrate human diversity. Respect for human differences is

evident throughout. Examples and research findings from many parts of the world are not add- ons but are integral to our understanding of child development. A list of these examples and research is available at macmillanlearning.com.

Learning to Button Most shirts for 4-year-olds are wide-necked without buttons, so preschoolers can put the shirts on themselves. But the skill of buttoning is best learned from a mentor, who knows how to increase motivation.

Current Research from the Field My mentors encouraged curiosity, creativity, and skepticism; as a result, I read and analyze thousands of articles and books on everything from the genetic alleles that predispose children to autism spectrum disorder to the complications of ethnic identity. The recent explosion of research in neuroscience has challenged me, once again, first to understand and then to explain many complex findings and speculative leaps. My students continue to ask questions and share their experiences, providing new perspectives and concerns.

Topical Organization Within a Chronological Framework The book’s basic organization remains unchanged. Four chapters begin the book with coverage of definitions, theories, genetics, and prenatal development. These chapters function not only as a developmental foundation but also as the structure for explaining plasticity, nature and nurture, multicultural awareness, risk analysis, gains and losses, family bonding, and many other concepts that yield insights for all of human development.

The other three parts correspond to the major periods of development. Each age is discussed in three chapters, one for the biological, one for the cognitive, and one for the social world. I believe that this topical organization within a chronological framework provides a scaffold for students’ understanding of the interplay between chronological age and specific topics.

http://macmillanlearning.com
Sisters and Brothers Gender equality has become important to both sexes, as evidenced by the thousands of men who joined the Women’s March on January 21, 2017—the day after President Trump’s inauguration. Many who attended took exception with his positions on sex and gender issues, and the result was one of the largest protest marches ever: an estimated 4 million people in more than one hundred towns and cities. This shows Washington, D.C., where more than half a million gathered.

Photographs, Tables, and Graphs That Are Integral to the Text Students learn a great deal from this book’s illustrations because Worth Publishers encourages authors to choose the photographs, tables, and graphs and to write captions that extend the content. Observation Quizzes that accompany many of them inspire readers to look more closely at certain photographs, tables, and figures. The online Data Connections further this process by presenting numerous charts and tables that contain detailed data for further study.

Media and Supplements After teaching for many years, I know personally that supplements can make or break a class, and that some publisher’s representatives are helpful in explaining how to use them while others are not. Many new quizzes, videos, and other aids are available for both students and professors. Ask your publisher’s representative how these might be used. I have taught with texts from many publishers; I expect you will find that Worth representatives are among the best, and you will be glad you asked for help.

Global Decay Thousands of children in Bangalore, India, gathered to brush their teeth together, part of an oral health campaign. Music, fast food, candy bars, and technology have been exported from the United States, and many developing nations have their own versions (Bollywood replaces Hollywood). Western diseases have also reached many nations; preventive health now follows.

Observation Quiz Beyond toothbrushes, what other health tools do most children here have that their parents did not? (see answer, p. 314)

LaunchPad with Developing Lives, LearningCurve Quizzing, and Data Connections Activities Built to solve key challenges in the course, LaunchPad gives students what they need to prepare for class and gives instructors what they need to set up a course, shape the content, craft presentations and lectures, assign and assess homework, and guide the learning of every student.

LaunchPad, which can be previewed at launchpadworks.com, includes the following:

http://launchpadworks.com
An interactive e-Book, which integrates the text with videos that aid student learning. Developing Lives, the sophisticated interactive experience in which students “raise” their own virtual child. This fascinating simulation integrates more than 200 videos and animations and includes quizzes and essay questions that are easy to assign and assess. Data Connections, interactive activities that allow students to interpret data on topics ranging from breast-feeding to risk-taking. The LearningCurve adaptive quizzing system, which is based on the latest findings from learning and memory research. It combines adaptive question selection, immediate and valuable feedback, and a gamelike interface to engage students in a learning experience that is unique to them. Each LearningCurve quiz is fully integrated with other resources in LaunchPad through the Personalized Study Plan, so students can review using Worth’s extensive library of videos and activities. And state-of-the-art question analysis reports allow instructors to track the progress of individual students as well as their class as a whole. Worth’s Video Collection for Human Development, which covers the full range of the course, from classic experiments (like the Strange Situation and Piaget’s conservation tasks) to investigations of children’s play to adolescent risk-taking. Instructors can assign these videos to students through LaunchPad or choose 1 of 50 popular video activities that combine videos with short-answer and multiple-choice questions. (For presentation purposes, our videos are also available on flash drive.) Instructor’s Resources, which has been hailed as the richest collection of instructor’s resources in developmental psychology. They include learning objectives, springboard topics for discussion and debate, handouts for student projects, course-planning suggestions, ideas for term projects, and a guide to audiovisual and online materials. Lecture Slides, which include two sets of prebuilt slides: one comprised of chapter art and illustrations, and another consisting of comprehensive, book-specific lectures. These slides

can be used as-is or customized to fit your course needs. A Test Bank containing at least 100 multiple-choice and 70 fill-in-the-blank, true-false, and essay questions per chapter. Good test questions are critical to every course, and we have gone through each and every one of these test questions with care. We have added more challenging questions, and questions are keyed to the textbook by topic, page number, and level of difficulty. Questions can be organized by NCLEX, NAEYC, and APA goals and Bloom’s taxonomy. We have also written rubrics for grading all of the essay questions in the test bank.

The Diploma computerized test bank guides instructors step by step through the process of creating a test. It also allows them to quickly add an unlimited number of questions; edit, scramble, or re-sequence items; format a test; and include pictures, equations, and media links. The accompanying gradebook enables instructors to record students’ grades throughout the course and includes the capacity to sort student records, view detailed analyses of test items, curve tests, generate reports, and add weights to grades.

Thanks I would like to thank the academic reviewers who have read this book in every edition and who have provided suggestions, criticisms, references, and encouragement. They have all made this a better book.

I want to mention especially those who have reviewed this edition:

Chris Alas, Houston Community College Adrienne Armstrong, Lone Star College William Robert Aronson, Florida International University T. M. Barratt, Arizona State University Daniel Benkendorf, The City University of New York–Baruch College Gina Brelsford, Pennsylvania State University–Harrisburg Melissa A. Bright, University of Florida Alda Cekrezi, Lone Star College Kristi Cordell-McNulty, Angelo State University Barbara Crosby, Baylor University Faith T. Edwards, Univeristy of Wisconsin—Oshkosh Naomi Ekas, Texas Christian University Michael A. Erickson, Hawaii Pacific University Diane Klieger Feibel, University of Cincinnati—Blue Ash College Lori Neal Fernald, The Citadel Military College of South Carolina Valerie C. Flores, Loyola University Chicago Stacie Foster, Arizona State University Kathryn Frazier, Northeastern University Christopher Gade, Berkeley City College Dan Grangaard, Austin Community College Jiansheng Guo, California State University—East Bay Pinar Gurkas, Clayton State University E. Allison Hagood, Arapahoe Community College

Toni Stepter Harris, Virginia State University Raquel Henry, Lone Star College—Kingwood Danelle Hodge, California State University—San Bernadino Vernell D. Larkin, Hopkinsville Community College Richard Marmer, American River College Jerry Marshall, Green River College T. Darin Matthews, The Citadel Military College of South Carolina Elizabeth McCarroll, Texas Woman’s University Alejandra Albarran Moses, California State University–Los Angeles Kelly A. Warmuth, Providence College

The editorial, production, and marketing people at Worth Publishers are dedicated to meeting the highest standards of excellence. Their devotion of time, effort, and talent to every aspect of publishing is a model for the industry, and the names of all those who helped with this edition are listed on the second page of this book. I particularly would like to thank Andrea, Chris, and Chuck.

New York July 2017

The Beginnings

PART I CHAPTERS 1-2-3-4

APPLICATION TO DEVELOPING LIVES PARENTING SIMULATION INTRODUCTION AND PRENATAL

T

DEVELOPMENT

In the Introduction module of Developing Lives, you will begin to customize the developmental journey of your child with information about your personality, cognitive abilities, and demographic characteristics. Next, as you progress through the Prenatal simulation module, how you decide the following will impact the biosocial, cognitive, and psychosocial development of your baby.

Biosocial Cognitive Psychosocial

Will you modify your behaviors and diet during pregnancy?

Will you find out the gender of your baby prior to delivery?

What kind of delivery will you and your partner plan for (in the hospital with medication, at home with a doula, etc.)?

Are you going to talk to your baby while he or she is in the womb?

How much does your baby understand during prenatal development?

How will your relationship with your partner change as a result of the pregnancy?

Will you begin bonding with your baby prior to birth?

he science of human development includes many beginnings. Each of the first four chapters of this text forms one corner of a solid foundation for our study.

Chapter 1introduces definitions and dimensions, explaining research strategies and methods that help us understand how people develop. The need for science, the power of culture, and the necessity of an ecological approach are all explained.

Without ideas, our study would be only a jumble of observations. Chapter 2 provides organizing guideposts: Five major theories, each leading to many other theories and hypotheses, are described.

Chapter 3 explains heredity. Genes never act alone, yet no development — whether in body or brain, at any time, in anyone — is unaffected by DNA.

Chapter 4 details the prenatal growth of each developing person from a single cell to a breathing, grasping, crying newborn. Many circumstances — from the mother’s diet to the father’s care to the culture’s values — affect development during every day of embryonic and fetal growth.

As you see, the science and the wonder of human life begin long before birth. These four chapters provide the basic ideas and concepts that enable us to understand each developing child — and all of the rest of us.

The Science of Human Development CHAPTER

1

✦ Understanding How and Why The Scientific Method A VIEW FROM SCIENCE: Overweight Children and Adult Health The Nature–Nurture Controversy

✦ The Life-Span Perspective Development Is Multidirectional Development Is Multicontextual INSIDE THE BRAIN: Thinking About Marijuana Development Is Multicultural Development Is Multidisciplinary Development Is Plastic A CASE TO STUDY: David

✦ Designing Science Observation The Experiment The Survey Studying Development over the Life Span

✦ Cautions and Challenges from Science Correlation and Causation Quantity and Quality Ethics

What Will You Know?1

1. Why is science especially crucial for understanding how people develop?

2. Are children always and everywhere the same, or is each child unique, changing from day to day and place to place?

3. What methods are used to study development?

4. What must scientists do to make their conclusions valid and ethical?

hen I was 4 years old, professional photographers came to our house to take pictures of my

Wmother and me, wearing matching dresses. I was bathed and dressed for the occasion,and my mother wore lipstick and perfume. Right before they came, I found a scissors andcut my hair. My mother stopped me before I could finish, but some tufts were short. She laughed, tying bows to make my hair presentable. I do not remember any of this, but my mother has told this anecdote many times. There are photographs to prove it.

What surprises you most about this memory? Is it normal for children to misbehave, or does my hair-cutting suggest something pathological — maybe defiance, or antisocial behavior? Would you have punished me if I were your child?

What about this incident reflects culture and history — maybe photographers coming to homes, mother–daughter dresses, lipstick, ribbons, scissors within a child’s reach? Why did my mother laugh and cherish the memory?

This chapter introduces the developmental perspective, which seeks to answer questions like these. Every action of each child could be natural, could be cultural, or could reflect something odd about their genes or upbringing. To really understand this incident, we need research — on other 4-year-olds, on other mothers, and on my mother and me over the years.

Perhaps my mother did not want those photographers, but, as expected of wives at the time, she may have agreed to please my father. But perhaps she resented the pressure on appearance, so she was glad that I cut my hair. Does that interpretation come from my current viewpoint, not from hers? Maybe, maybe not.

You, and everyone who was ever a child, experienced dozens of incidents like this one. Are you the product of genes, culture, context, or child rearing? This chapter suggests how to find answers.

Understanding How and Why The science of human development seeks to understand how and why people—all kinds of people, everywhere, of every age—change or remain the same over time. The goal is for the 7.6 billion people on Earth to fulfill their potential. Their development is multidirectional, multicontextual, multicultural, multidisciplinary, and plastic, five terms that will be explained soon.

science of human development The science that seeks to understand how and why people of all ages change or remain the same over time.

First, however, we need to emphasize that developmental study is a science. It depends on theories, data, analysis, critical thinking, and sound methodology, just like every other science. All scientists ask questions and seek answers in order to ascertain “how?” and “why?”

Science is especially useful when we study people: Lives depend on it. What should pregnant women eat? How much should babies cry? When should children be punished, how, and for what? Should schools be coed or single-sex, public or private? Should education encourage independence or obedience, be optional or required, through eighth grade or twelfth grade? People disagree about all this and more, sometimes vehemently.

The Scientific Method Almost everyone cares about children, yet many people respond to children without understanding them. Disputes occur often because facts are unknown, and applications spring from assumptions, not from data.

Five Crucial Steps To avoid unexamined opinions, to rein in personal biases, and to discover new truths, researchers follow the five steps of the scientific method (see Figure 1.1):

FIGURE 1.1 Process, Not Proof Built into the scientific method—in questions, hypotheses, tests, and replication—is a passion for possibilities, especially unexpected ones.

scientific method A way to answer questions using empirical research and data-based conclusions.

1. Begin with curiosity. On the basis of theory, prior research, or a personal observation, pose a question.

2. Develop a hypothesis. Shape the question into a hypothesis, a specific prediction to be examined.

3. Test the hypothesis. Design and conduct research to gather empirical evidence (data). 4. Analyze the evidence. Conclude whether the hypothesis is supported or not. 5. Report the results. Share the data, conclusions, and alternative explanations.

hypothesis A specific prediction that can be tested.

empirical evidence Evidence that is based on observation, experience, or experiment; not theoretical.

Replication As you see, developmental scientists begin with curiosity and then seek the facts, drawing conclusions after careful research. Reports are written so that other scientists can examine the procedures, analyze the data, check the conclusions, and then replicate the results.

Replication—repeating the study with different participants — is needed before conclusions are considered solid. Scientists study the reports (Step 5) of other scientists and build on what has gone before. Sometimes they try to duplicate a study exactly, using the same methods; often they follow up with related research (Stroebe & Strack, 2014). Conclusions are then revised, refined, rejected, or confirmed.

replication Repeating a study, usually using different participants, sometimes of another age, socioeconomic status (SES), or culture.

Obviously, the scientific method is not foolproof. Scientists may draw conclusions too hastily, misinterpret data, or ignore alternative perspectives. The results from one group of people may differ from the results from another group. Sometimes scientists discover outright fraud (Bouter, 2015). Ideally, results are replicated, not only by conducting the same research again but also by designing other research that will verify and extend the same hypothesis (Larzelere et al., 2015).

An effort to replicate 100 published studies in psychology found that about one-third did not produce the same results and another one-third were less conclusive than the original (Open Science Collaboration, 2015). Problems often arose from the research design (Step 3) of the original studies and the pressure to publish.

The push for replication is welcomed by scientists in many disciplines. For instance, educators reevaluated the effects of preschool education paid by state taxes in Virginia. They confirmed that children who attended preschool recognized nine more letters, on average, than children of

the same age who did not (Huang, 2017). Since replication reveals that some well-intentioned programs are not effective, it is good to know that this one was.

Asking questions and testing hypotheses are crucial for every aspect of child development. A View from Science shows this process in more detail.

A VIEW FROM SCIENCE

Overweight Children and Adult Health2

Obesity is a serious problem. Over the life span, from infancy to age 60, rates of obesity increase, and with it, rates of diabetes, heart disease, and stroke. The connection between overweight and disease was not always known. Indeed, the opposite seemed true.

Since tiny newborns and underweight children are more likely to die, people made a logical, but false, assumption: Heavier children must be healthier (Laraway et al., 2010).

That assumption had fatal consequences. Adults were proud of their pudgy babies and overfed their children. Not until the middle of the twentieth century, in the famous Framingham Heart Study, did scientists discover that obese adults risked premature death— of heart disease, stroke, diabetes, and many other ailments.

This discovery sparked a new question (Step 1): Was childhood obesity a health risk when those children grew up? That led to a hypothesis (Step 2) that overweight in childhood impairs health in adulthood.

What Will Become of Her? This happy, beautiful girl in Sweden may become an overweight woman . . . or she may not. Research finds that if she slims down by adulthood, she is likely to be healthier than the average woman who was never overweight.

This hypothesis is now widely assumed to be true. For instance, a poll found that most Californians consider childhood obesity “very serious,” with one-third of them rating poor eating habits as a worse risk to child health than drug use or violence (Hennessy-Fiske, 2011). But is their assumption valid?

The best way to test that hypothesis (Step 3) is to examine adult health in people who had been weighed and measured in childhood. Several researchers did exactly that, using data on children’s height and weight—and their measurements as adults—from four studies. A summary of those studies (Juonala et al., 2011) found that most people (83 percent) maintained their relative weight. Thus most overweight children became overweight adults. (See Figure 1.2a.) Analysis of those data led to a strong conclusion (Step 4), which was then published (Step 5): Overweight children are likely to become obese adults.

FIGURE 1.2 Not Yet Obese You probably know that more than half of all adults in the United States are overweight, so this chart—with only 21 percent of adults obese—may seem inaccurate. However, three facts explain why the data are accurate: (1) “Obese” is much heavier than overweight; (2) the average adult in this study was 34 years old (middle-aged and older adults are more often obese); and (3) one of the studies that provided much of the longitudinal data was in Finland, where rates of obesity are lower than in the United States.

Other research finds that childhood obesity is increasing in almost every nation of the world, including those countries where, in the past, malnutrition and infectious diseases were prime causes of child death. That is no longer true: Very few children die of malnutrition, but many become overweight adults, a health hazard that can be traced to childhood. As one review states it:

The prevalence of overweight and obesity in children and adults continues to increase worldwide and, because of their association with cardiovascular disorders, diabetes, and dyslipidemia, are becoming one of the major health issues.

[Susic & Varagic, 2017, p. 139]

For instance, in those four studies, 29 percent of the adults who were overweight all their lives had high blood pressure, compared to 11 percent of those who were never overweight (Juonala et al., 2011). Hypertension is a proven risk factor for heart disease and strokes, which are becoming the most common cause of death in poor nations (Mozaffarian et al., 2016).

A new question arose (Step 1), building on those earlier findings. What about overweight children who become normal-weight adults? Have they already harmed their health? That led to another hypothesis (Step 2): Overweight children will have a higher rate of heart attacks, strokes, diabetes, and death in adulthood, even if they slim down. The research design (Step 3) was to measure indications of health in adults who had been overweight as children but who now were normal weight.

The data (Step 4)disproved the hypothesis (see Figure 1.2b): As normal-weight adults, those who had been overweight as children were not at high risk of disease, a conclusion replicated by several studies with quite different populations (Juonala et al., 2011). Scientists were happy with that conclusion— disproving a commonly believed hypothesis may be even more welcome than proving it, because science ideally uncovers false assumptions as well as confirms true ones.

Many other issues, complications, and conclusions regarding diet are discussed later in this book. For now, all you need to remember are the steps of the scientific method and that developmentalists are right: Significant “change over time” is possible.

The Nature–Nurture Controversy An easy example of the need for science concerns a great puzzle of life, the nature—nurture debate. Nature refers to the influence of the genes that people inherit. Nurture refers to influences from the environment, which is broadly interpreted to include the entire context of development. The environment begins with the health and diet of the embryo’s mother and continues lifelong, including experiences in the family, school, community, and nation.

nature In development, nature refers to the traits, capacities, and limitations that each individual inherits genetically from his or her parents at the moment of conception.

nurture In development, nurture includes all of the environmental influences that affect the individual after conception. This includes everything from the mother’s nutrition while pregnant to the cultural influences in the nation.

The nature—nurture debate has many manifestations, among them heredity-environment, maturation-learning, and sex-gender. Under whatever name, the basic question is, “How much of any characteristic, behavior, or emotion is the result of genes, and how much is the result of experience?“

Some people believe that most traits are inborn, that children are innately good ("an innocent child") or bad (“beat the devil out of them”). Others stress nurture, crediting or blaming parents, neighborhood, drugs, or even food, when someone is good or bad, a hero or a scoundrel.

Neither belief is accurate. The question is “how much,” not “which,” because both genes and the environment affect every characteristic: Nature always affects nurture, and then nurture affects nature. Even “how much” is misleading, because it implies that nature and nurture each contribute a fixed amount. Instead, the dynamic interaction between them shapes the person (Eagly & Wood, 2013; Lock, 2013; Shulman, 2016).

A further complication is that the impact of any good or bad experience — a beating, or a beer, or a blessing—is magnified or inconsequential because of the particular genes or events. Thus, every aspect of nature and nurture depends on other aspects of nature and nurture in ways that vary for each person.

Chopin’s First Concert Frederick Chopin, at age 8, played his first public concert in 1818, before photographs. But this photo shows Piotr Pawlak, a contemporary prodigy playing Chopin’s music in the same Polish Palace where that famous composer played as a boy. How much of talent is genetic and how much is cultural—a nature-nurture question that applies to both boys, 200 years apart.

Epigenetics The science of this interaction is explored in epigenetics, the study of the many ways in which the environment alters genetic expression. Epigenetics begins with methylation at conception and continues lifelong. For example, brain formation is directed by genes inherited at conception, but those genes are not alone. Soon, nutrients and toxins affect the prenatal brain, nurture affecting nature.

epigenetics The study of how environmental factors affect genes and genetic expression—enhancing, halting, shaping, or altering the expression of genes.

Not only do biological influences shape the brain, social experiences do as well. Chronic loneliness, for example, changes brain structures (Cacioppo et al., 2014). More than that, over thousands of years, human experiences shape genes. We are affected not only by our own nature and nurture but also by the nature and nurture of our parents, grandparents, and so on (Young, 2016).

Sometimes protective factors, in either nature or nurture, outweigh our liabilities. As one review explains, “there are, indeed, individuals whose genetics indicate exceptionally high risk of disease, yet they never show any signs of the disorder” (Friend & Schadt, 2014, p. 970). Why? Epigenetics. [Developmental Link: More discussion of epigenetics occurs in Chapter 3.]

Dandelions and Orchids There is increasing evidence of differential susceptibility — that sensitivity to any particular experience differs from one person to another because of the particular genes each person has inherited, or because of events that the person experienced years earlier.

differential susceptibility The idea that people vary in how sensitive they are to particular experiences. Often such differences are genetic, which makes some people affected “for better or for worse” by life events. (Also called differential sensitivity.)

Some people are like dandelions — hardy, growing and thriving in good soil or bad, with or without ample sun and rain. Other people are like orchids — quite wonderful, but only when ideal growing conditions are met (Ellis & Boyce, 2008; Laurent, 2014).

For example, in one study, depression in pregnant women was assessed and then the emotional maturity of their children was measured. Those children who had a particular version of the serotonin transporter gene (5-HTTLPR) were likely to be emotionally immature if their mothers were depressed, but more mature than average if their mothers were not depressed (Babineau et al., 2015).

Each of us carries both joys and scars from childhood experiences that would not have affected another person. Think about your favorite teacher. What about you — either in your genes or in your experiences—made that particular teacher wonderful for you? Could that same teacher be hated, or ignored, by another student? That’s differential susceptibility.

THINK CRITICALLY:3 Should we try to assign a percent to nature and a percent to nurture so that they add up to 100 percent?

Male and Female The nature—nurture debate is not merely academic. In a tragic case, an infant’s penis was mistakenly destroyed in 1966. At that time, sex differences were thought to originate from the genitals and child rearing, not from the genes. So his parents had his testicles removed and renamed him Brenda. They raised him as a girl (Money & Ehrhardt, 1972).

But we now know that some male—female differences are genetic and hormonal— in the brain, not the body; in nature, not nurture. After a troubled childhood, Brenda chose to become David, a man, at age 15. That was too late; David killed himself at age 38 (Diamond & Sigmundson, 1997; Associated Press, 2004).

From this example, it is tempting to conclude that all male—female differences are due to nature, but that would be incorrect. For instance, it was once believed that biology made females inferior in math. Girls who wanted to be physicists or engineers were told to choose another career. But in the 1960s millions of women insisted that nurture, not nature, kept women from excelling in math.

Consequently, more girls were allowed to study calculus. Recent international tests find that math scores of the two sexes have become quite similar: In some nations (Russia, Singapore, Algeria, and Iran) girls are ahead of boys! The practical implications of that research are that college women are encouraged to become engineers, physicists, or chemists (Brown & Lent, 2016). The scientific implications are, again, that nature and nurture interact, in sex differences and in everything else.

Video Activity: The Boy Who Was a Girl examines the case of David/Brenda Reimer and what it means to be a boy or a girl.4

WHAT HAVE YOU LEARNED?5

1. What are the five steps of the scientific method? 2. What is the difference between asking a question (Step 1) and developing a hypothesis (Step

2)? 3. Why is replication important for scientific progress? 4. What basic question is at the heart of the nature-nurture controversy? 5. When in development does nature begin to influence nurture? 6. What is the difference between genetics and epigenetics?

7. How might differential susceptibility be evident when students respond to a low exam grade?

The Life-Span Perspective The life-span perspective (Baltes, 1987; Fingerman et al., 2011; Lerner et al., 2014) began as a lens through which to view the entire human life span, particularly adult development. Insights from that perspective soon transformed our understanding of development at every age. The crucial idea is that, at every moment in life, context and culture affect each person’s past and shape their future. The life-span perspective views development as multidirectional, multicontextual, multicultural, multidisciplinary, and plastic (Baltes et al., 2006; Barrett & Montepare, 2015; Raz & Lindenberger, 2013).

life-span perspective An approach to the study of human development that takes into account all phases of life, not just childhood or adulthood.

Development Is Multidirectional Multiple changes, in every direction, characterize development. Traits appear and disappear, with increases, decreases, and zigzags (see Figure 1.3). An earlier assumption — that all development advances until about age 18, steadies, and then declines—has been soundly disproven by life- span research.

FIGURE 1.3 Patterns of Developmental Growth Many patterns of developmental growth have been discovered by careful research. Although linear (or nonlinear) progress seems most common, scientists now find that almost no aspect of human change follows the linear pattern exactly.

Patterns of Change Sometimes discontinuity is evident: Change can occur rapidly and dramatically, as when caterpillars become butterflies. Sometimes continuity is found: Growth can be gradual, as when redwoods add rings over hundreds of years. Some characteristics do not seem to change at all: The person I am now is an older version of the person I was as an infant. The same is true of you.

Children experience simple growth, radical transformation, improvement, and decline as well

as stability, stages, and continuity — day to day, year to year, and generation to generation. Not only do the pace and direction of change vary, but each characteristic follows its own trajectory.

Losses in some abilities occur simultaneously with gains in others. For example, babies lose some ability to distinguish sounds from other languages when they begin talking in whatever language they hear; school-age children become quite realistic, losing some of the magical imagination of younger children.

Critical and Sensitive Periods The timing of losses and gains, impairments or improvements, varies as well. Some changes are sudden and profound because of a critical period, which is either when something must occur to ensure normal development or the only time when an abnormality might occur. For instance, the human embryo grows arms and legs, hands and feet, fingers and toes, each over a critical period between 28 and 54 days after conception. After that, it is too late: Unlike some insects, humans never grow replacement limbs.

critical period A crucial time when a particular type of developmental growth (in body or behavior) must happen for normal development to occur, or when harm (such as a toxic substance or destructive event) can occur.

We know this fact because of a tragic episode. Between 1957 and 1961, thousands of newly pregnant women in 30 nations took thalidomide, an antinausea drug. This change in nurture (via the mother’s bloodstream) disrupted nature (the embryo’s genetic program).

If an expectant woman ingested thalidomide during the critical period for limb formation, her newborn’s arms or legs were malformed or absent (Moore et al., 2015, p. 480). Whether all four limbs, or just arms, hands, or fingers were missing depended on exactly when the drug was taken. If thalidomide was ingested only after day 54, no harm occurred.

Life has few such dramatic critical periods. Often, however, a particular development occurs more easily—but not exclusively — at a certain time. That is called a sensitive period.

sensitive period A time when a certain type of development is most likely, although it may still happen later with more difficulty. For example, early childhood is considered a sensitive period for language learning.

An example is learning language. If children do not communicate in their first language between ages 1 and 3, they might do so later (hence, these years are not critical), but their grammar is impaired (hence, these years are sensitive).

Similarly, childhood is a sensitive period for learning to speak a second or third language with native pronunciation. Adults who master new languages are asked, “Where are you from?” by those who can detect an accent, even when the speaker does not. Indeed, adults born in the United States whose first language was English reveal whether they grew up in Boston, Brooklyn, or Boise. The same is true within every other nation, as the tone, timing, and pronunciation of every language varies by region and social class.

Sometimes the multidirectional nature of development shows the influence of national culture. Childhood and adolescence are a sensitive period for attitudes about psychosocial drugs, as

evident from changes in acceptance of marijuana. This is discussed further in Inside the Brain.

I Love You, Mommy We do not know what words, in what language, her son is using, but we do know that Sobia Akbar speaks English well, a requirement for naturalized U.S. citizens. Here she obtains citizenship for her two children born in Pakistan. Chances are they will speak unaccented American English, unlike Sobia, whose accent might indicate that she learned British English as a second language.

Development Is Multicontextual The second insight from the life-span perspective is that “human development is fundamentally contextual” (Pluess, 2015, p. 138). Some of the many contexts that affect development are physical (climate, noise, population density, etc.); some relate to family (parents’ relationship, siblings’ values, income, other relatives, etc.); and some to community (urban, suburban, or rural; multiethnic or not; etc.).

INSIDE THE BRAIN

Thinking About Marijuana 6

Brains are affected by drugs, for better or worse, in two ways. First, structural changes are possible in the size and activity of particular regions. Second, the links between neurons are strengthened or weakened. These findings again reveal differential susceptibility, as well as multidirectional development.

The most studied drug is alcohol, which (1) reshapes the brain during fetal development and (2) strengthens desire. As a result, (1) some newborns are brain damaged lifelong, and (2) some social drinkers suddenly find that a drink awakens neuronal links that make another drink impossible to refuse.

Now consider marijuana. Links between fear from part of the brain (the amygdala) or pleasure from other parts of the brain (especially in the basal ganglia) precede drug use. Both are multidirectional, powerfully affected by childhood. Consequently, attitudes change because of the rise and fall of fear (see Figure 1.4).

FIGURE 1.4 Double Trends Both cohort and generational trends are evident. Note that people of every age are becoming more accepting of marijuana, but the effect is most obvious for adults who never heard about “reefer madness.”

Observation Quiz Why is the line for the 1981-1997 cohort much shorter than the line for the older cohorts? (see answer, p. 14)7

In the United States in the 1930s, marijuana was declared illegal. The 1936 movie Reefer Madness was shown until about 1960, with vivid images connecting marijuana with a warped brain, suicide, and insanity. Most adolescents feared and shunned marijuana. However, marijuana was part of the jazz and popular music scene: In the 1960s, the Beatles, Bob Dylan, James Brown, and Bob Marley smoked it and sang about it.

Young adolescents listened to that music, resisted adult rules, and increasingly tried marijuana themselves. By 1980, half of all high school seniors had smoked “weed” in the previous year, according to Monitoring the Future . an annual report (Miech et al., 2016).

That worried older adults, whose emotional reactions to marijuana had been formed decades earlier. They believed it would permanently damage vulnerable teenage brains, leading to psychological disorders and drug addiction (Estroff & Gold, 1986).

President Nixon declared that drug abuse (especially marijuana, but not cigarettes or alcohol) was “Public Enemy Number One.” A decade later, Nancy Reagan (first lady from 1981 to 1989) advocated, “Just say no to drugs.” That affected the attitudes and behavior of the next cohort: By 1991, the rate of high school seniors who had ever tried marijuana (21 percent) was only one-third of what it had been.

Attitudes, politics, and behavior are multidirectional, and so another shift has occurred. The parents of current adolescents are not from the generation that most feared the drug. One result is that far fewer (30 percent) of their teenagers think regular use of marijuana is “a great risk,” compared to about 80 percent in the early 1980s. Behavior has shifted as well: In 2016, 38 percent of high school students reported smoking marijuana in the past year.

This signifies changes in the neurological links to marijuana use—irrational fears and desires. Some evidence finds that marijuana smoking alters the brain (Mandelbaum & de la Monte, 2017), but many scientists are not convinced. Some question research that finds a correlation between marijuana use and “structural abnormalities in the brains of young people,” but we lack good “scientific evidence about the effects of marijuana on the adolescent brain.” As a result, we are “gambling with the health and safety of our youth” (DuPont & Lieberman, 2014, p. 557).

It may be that pregnant women who use marijuana damage the brains of their fetus (Alpár et al., 2016; Volkow et al., 2017). On the other hand, some find that marijuana relieves pain, with fewer dangerous side effects (addiction and death) than prescribed opiates (Miller, 2016).

The best we have longitudinally may be from Australians who were regular users of marijuana from age 18 on. By midlife, they had more financial and relationship problems than those who were drug-free—but not more than those who abused alcohol (Cerdá et al., 2016). However, data on Australians who smoked an illegal drug 20 years ago may not apply to Americans now.

Unfortunately, federal laws passed decades ago impede current research: Longitudinal, unbiased studies on

brain benefits and costs of marijuana have not been published, and earlier data may confuse correlation with causation (a topic discussed at the end of this chapter).

We know that the effects of the drug on the brain vary, and that just thinking about marijuana triggers extreme brain reactions, including phobia and ecstasy. Are current attitudes (mostly positive) more rational than the mostly negative ones of our great-grandparents? More science needed.

For example, a student might decide on a whim to stop by a social gathering instead of heading straight to the library. The social context of the party (perhaps free drinks and food, lively music, many friends, ample room, and interesting strangers) is influential, affecting that student’s performance in class the next morning, and perhaps his or her future. We each encounter several contexts each day, some by choice and some not; they all could affect our later thoughts and actions.

Ecological Systems Leading developmentalist Urie Bronfenbrenner (1917–2005) emphasized the importance of considering contexts. Just as a naturalist studying an organism examines the ecology (the relationship between the organism and its environment) of a tiger, or a tree, or a trout, Bronfenbrenner recommended an ecological-systems approach (Bronfenbrenner & Morris, 2006) to study humans.

ecological-systems approach A perspective on human development that considers all of the influences from the various contexts of development. (Later renamed bioecological theory.)

Where in the World? Like every child, this boy is influenced by dozens of contexts from each of Bronfenbrenner’s systems, some quite direct and some in the macro-and exosystems. His cap (called a kopiah), diligence, all-boys school, and slanted desk each affects his learning, but those could occur in many nations—in the Americas, Europe, or Africa. In fact, this is in Asia, in Kota Bharu, Malaysia.

This approach recognizes three nested levels (see Figure 1.5). Most obvious are microsystems — each person’s immediate social contexts, such as family and peer group. Next are exosystems (local institutions such as school and church, temple, or mosque) and then macrosystems (the larger social setting, including cultural values, economic conditions, and political processes).

FIGURE 1.5 The Ecological Model According to developmental researcher Urie Bronfenbrenner, each person is significantly affected by interactions among a number of overlapping systems, which provide the context of development. Microsystems —family, peer group, classroom, neighborhood, house of worship—intimately and immediately shape human development. Surrounding and supporting the microsystems are the exosystems, which include all the external networks, such as community structures and local educational, medical, employment, and communications systems, that affect the microsystems. Influencing both of these systems is the macrosystem, which includes cultural patterns, political philosophies, economic policies, and social conditions. Mesosystems refer to interactions among systems, as when parents and teachers coordinate to educate a child. Bronfenbrenner eventually added a fifth system, the chronosystem, to emphasize the importance of historical time.

Two more systems affect these three. One is the chronosystem (literally, “time system”), which is the historical context. The other is the mesosystem, consisting of the connections among the other systems.

Toward the end of his life, Bronfenbrenner renamed his approach bioecological theory to highlight the role of a sixth set of systems, those within the body (e.g., the sexual-reproductive system, the cardiovascular system) that affect the external systems (Bronfenbrenner & Morris, 2006).

Bronfenbrenner’s perspective remains useful. For example, a puzzling fact is that children who have been sexually abused are likely to be abused again, in childhood and adulthood. Why? Fault of the family? The culture?

Perhaps all three and more. Psychologists using the bioecological approach to analyze repeated sexual victimization conclude that the micro-, macro-, and exosystems each have an impact (Pittenger et al., 2016).

History and Social Class Two contexts — the historical and the socioeconomic — are basic to understanding everyone, from conception onward. Since they are relevant to every stage, we explain them now.

People born within a few years of one another are called a cohort, a group defined by its members’ shared age. Cohorts travel through life together, affected by the values, events, technologies, and culture of the historical period as it interacts with their age at the time. From the moment of birth, when parents name their baby, historical context affects what may seem like a private and personal choice (see Table 1.1).

cohort People born within the same historical period who therefore move through life together, experiencing the same events, new technologies, and cultural shifts at the same ages. For example, the effect of the Internet varies depending on what cohort a person belongs to.

TABLE 1.1

Popular First Names

Girls

2015: Emma, Olivia, Sophia, Isabella, Ava

1995: Jessica, Ashley, Emily, Samantha, Sarah

1975: Jennifer, Amy, Heather, Melissa, Angela

1955: Mary, Deborah, Linda, Debra, Susan

1935: Mary, Shirley, Barbara, Betty, Patricia

Boys

2015: Noah, Liam, Mason, Jacob, William

1995: Michael, Matthew, Christopher, Jacob, Joshua

1975: Michael, Jason, Christopher, James, David

1955: Michael, David, James, Robert, John

1935: Robert, James, John, William, Richard

Information from U.S. Social Security Administration.

If you know someone named Emma, she is probably young: Emma is the most common name for girls born in 2015 but was not in the top 100 until 1996, and not even in the top 1,000 in 1990. If you know someone named Mary, she is probably old: About 10 percent of all girls born from 1900 to 1965 were named Mary, but now Mary is unusual.

Two of my daughters, Rachel and Sarah, have names that were common when they were born.

One wishes she had a more unusual name; the other is glad she does not. That is differential susceptibility, which applies to you as well as to my daughters. Your name is influenced by history; your reaction is yours.

The second pervasive context is economic, reflected in a person’s socioeconomic status, abbreviated SES: (Sometimes SES is called tocial class, as in middle class or working class) SES reflects education, occupation, and neighborhood, as well as income.

socioeconomic status (SES) A person’s position in society as determined by income, occupation, education, and place of residence. (Sometimes called social class.)

Measuring SES is complex, especially internationally. The United Nations rates the United States and Canada as wealthy nations, but most North Americans do not consider themselves rich. (see Figure 1.6.)

FIGURE 1.6 Children of the Future The United States is an exception to a general rule: the wealthier a nation, the smaller the income gap. Since young families tend to be the least wealthy, and since education and health care are affected by neighborhood and employment, a wide gap bodes ill for children. Particularly troubling are the trend lines— unless changes occur, the United States will be worse than Mexico by 2035.

SES is not just about money. Suppose a U.S. family is comprised of an infant, an unemployed mother, and a father who earns less than $17,000 a year. Their SES would be low if they live in a violent, drug-infested neighborhood and the wage earner is a high school dropout working 45 hours a week for minimum wage (in 2016, the federal minimum wage was $7.25 an hour). But SES would be much higher if the wage earner is a postdoctoral student living on campus and teaching part time. Both of these families are below the official poverty line for a family of three ($19,790), but only one is low-SES.

SES brings advantages and disadvantages, opportunities and limitations — all affecting housing, health, nutrition, knowledge, and habits. Although low income obviously limits a child, other factors are pivotal, especially education and national policy.

Same Situation, Far Apart: Shelter Rules The homeless shelter in Paris, France (left) allows dogs, Christmas trees, and flat-screen televisions for couples in private rooms. The one in Cranston, Rhode Island (right) is only for men (no women, children, or dogs), who must leave each morning and wait in line each night for one of the 88 beds. Both places share one characteristic: Some of the homeless are turned away, as there is not room for everyone.

Answer to Observation Quiz (from p. 11) Because surveys rarely ask children their opinions, and the youngest cohort on this graph did not reach adulthood until about 2005.

For example, the nations of northern Europe seek to eliminate SES disparities as much as possible, and the health and school achievement of children from their low-income families are not far behind the richest children. By contrast, developing nations, especially in Latin America, tend to have large SES achievement gaps (Ravallion, 2014). Among advanced nations, the United States has “recently earned the distinction of being the most unequal of all developed countries” (Aizer & Currie, 2014, p. 856). Such differences by nation are a result of the macrosystem, not the microsystem.

Income differences are not only found by ethnic group but also by age. Young children with young parents are poorest, and poverty in early childhood reduces academic achievement even more than poverty during adolescence (Wagmiller 2015). The reason probably relates to the quality of education before age 5.

Development Is Multicultural In order to study “all kinds of people, everywhere, at every age,” research must include people of many cultures. For social scientists, culture is far more than food or clothes; it is a set of ideas, beliefs, and patterns of behavior.

culture A system of shared beliefs, norms, behaviors, and expectations that persist over time and prescribe social behavior and assumptions.

Creating Culture Culture is a powerful and pervasive social construction, that is, a concept created, or constructed, by a society. Social constructions affect how people think and act—what they value, ignore, and punish.

social construction An idea that arises from shared perceptions, not on objective reality. Many age-related terms (such as childhood, adolescence, yuppie, and senior citizen) are social constructions, strongly influenced by social assumptions.

Although most adults think they accept, appreciate, and understand many cultures, that may not be accurate. It is easy to overgeneralize, becoming simplistic about cultures that are not one’s own. For example, when people speak of Asian culture or Hispanic culture, they may be stereotyping, ignoring cultural differences between people from Korea and Japan, for instance, or those from Mexico and Guatemala.

Hard Floor, Hard Life These are among the thousands of unaccompanied minors who fled Latin America and arrived in Arizona and Texas in 2014. Developmentalists predict that the effects of their hazardous journey will stay with them, unless sources of resilience—such as caring family and supportive community—are quickly found. Culture and context affect everyone lifelong.

Observation Quiz How many children are sleeping here in this photograph? (see answer, p. 16)

Every generalization risks harming individuals. For example, the idea that Asian children are the “model minority” increases the pressure on children to excel, and then to be teased when they do. Further, some people in every group deliberately rebel against the expected beliefs and behaviors from their culture.

Thus, the words culture and multicultural need to be used carefully, especially when they are applied to individuals, lest one slides from awareness to stereotype.

In a diverse nation such as the United States, everyone is multicultural. Within each person, ethnic, national, school, and family cultures sometimes clash, with no one a pristine exemplar of

only one culture. One of my students, whose parents had immigrated to the United States, wrote:

My mom was outside on the porch talking to my aunt. I decided to go outside; I guess I was being nosey. While they were talking I jumped into their conversation which was very rude. When I realized what I did it was too late. My mother slapped me in my face so hard that it took a couple of seconds to feel my face again.

[C., personal communication]

Notice how my student reflects her mother’s culture; she labels herself “nosey” and “very rude.” She later wrote that she expects children to be seen, not heard. Her son makes her “very angry” when he interrupts.

In this example, she and her son both reflect U.S. culture, where talkative children are encouraged, as well as the culture of her mother’s homeland, where they are not. Do you think my student was nosey or, on the contrary, that her mother should not have slapped her? Or do you hesitate to choose either option? Your answer — or non-answer—reflects your culture.

As with my student’s mother, people tend to believe that their culture is better than others. This belief has benefits: People who endorse their culture’s attitudes and habits tend to be happy, proud, and willing to help strangers. However, that belief becomes destructive if it reduces respect for people from other groups. Thoughtlessly, differences are assumed to be inferior (Akhtar & Jaswal, 2013).

Difference and Deficit Developmentalists recognize the difference-equals-deficit error, which is the assumption that people unlike us (difference) are inferior (deficit). Sadly, when humans notice that someone else does not think or act as they do, the human tendency is to believe that such a person is to be pitied, feared, or encouraged to change. Even 3-year-olds assume that the way things are done by their parents, or in their community, is the right way (Schmidt et al., 2016).

difference-equals-deficit error The mistaken belief that a deviation from some norm is necessarily inferior to behavior or characteristics that meet the standard.

The difference-equals-deficit error is one reason that a careful multicultural approach is necessary. Never assume that another culture is wrong and inferior—or the opposite, right and superior. Assumptions can be harmful.

For example, one Japanese child, on her first day in a U.S. school, was teased for the food she brought for lunch. The next day, when she arrived at school, she dumped the contents of her lunchbox in the garbage — she would rather go hungry than be considered deficient.

Video: Research of Geoffrey Saxe further explores how difference does not equal deficit.

This example illustrates the problem with judging another culture: A Japanese lunch might, or might not, be healthier than a typical American one. The children did not know or care about

nutrition; they assumed that their usual lunch was best. Meanwhile, the Japanese child’s mother may have thought she was packing a better lunch than the standard U.S. one.

To further develop a multicultural perspective, we need to differentiate culture, ethnicity, and race . Members of an ethnic group almost always share ancestral heritage and often have the same national origin, religion, and language. That shared history affects them when they are far from their original home.

ethnic group People whose ancestors were born in the same region and who often share a language, culture, and religion.

Consequently, ethnic groups often share a culture, but this is not always true (see Figure 1.7). There are “multiple intersecting and interacting dimensions” to ethnic identity (Sanchez & Vargas, 2016 . p. 161). People may share ethnicity but differ culturally, especially if they left their original home long ago and adopted the culture of their new place, such as people of Irish descent in Ireland, Australia, and North America. The opposite is also true: People of many ethnic groups may all share a culture, as evident in all the people who identify with British, American, or Canadian culture.

FIGURE 1.7 Overlap—But How Much? Ethnicity, culture, and race are three distinct concepts, but they often—though not always—overlap.

Ethnicity is a social construction, a product of the social context, not biology. It is nurture, not nature, with specifics dependent on the other people nearby. For example, African-born people in North America typically consider themselves African, but African-born people in Africa identify with a more specific ethnic group. Awareness of ethnicity has increased in the United States, in part because the recent influx of immigrants has awakened an interest in family history among many Americans. People in the United States are more aware of ethnicity and race than people elsewhere (Verkuyten, 2016). That itself is cultural.

Answer to Observation Quiz (from p. 15) Nine—not counting the standing boy or the possible tenth one whose head is under the blanket. Rumpled blankets suggest that eight more are elsewhere at the moment. Each night hundreds of children sleep in this Border Protection Processing Facility in Brownsville, Texas. They are detained while authorities decide whether to send them back to the countries they fled or to a safe place in the United States.

Some Americans are puzzled by civil wars in distant nations (e.g., in Syria, or Sri Lanka, or Kenya), where bitter enemies may appear to be of the same ethnicity. Do not be surprised: Within every nation, people recognize ethnic differences that outsiders do not see. Social constructions are potent.