2. WHAT WILL YOU KNOW? How can the study of children, each one unique, be a science? Does his or her ethnic group make any difference in a child’s development? Is childhood today different from childhood fifty years ago? How can we know what changes between one year of life and the next? Is it unethical to study children scientifically? Do scientists always investigate the crucial questions?

3. Understanding How and Why The science of human development …seeks to understand how and why people of all ages and circumstances change or remain the same over time.

4. Understanding How and Why Three crucial elements in definition of science of development Science People Change

5. Understanding How and Why Scientific method Way to answer questions using empirical research and data-based conclusions. Five basic steps of the scientific method Begin with curiosity and pose a question. Develop a hypothesis. Test the hypothesis. Draw conclusions. Report the results.

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

7. Understanding How and Why Replication: The final step Repeating a study, usually using different participants, perhaps of another age, SES, or culture

8. The Nature-Nurture Controversy Nature Influence of genes we inherit Nurture Environmental influences that affect development Nature always affects nurture, and nurture always affects nature.

9. Some People Are Vulnerable Differential susceptibility: People differ in their susceptibility to environmental influence because of particular inherited genes.

10. Domains of Human Development Biosocial Development Includes all the growth and change that occur in a person’s body and the genetic, nutritional, and health factors that affect that growth and change. Motor skills—everything from grasping a rattle to driving a car—are also part of the biosocial domain. In this book, this domain is called biosocial, rather than physical or biological. Cognitive Development Includes all the mental processes that a person uses to obtain knowledge or to think about the environment. Cognition encompasses perception, imagination, judgment, memory, and language —the processes people use to think, decide, and learn. Education— not only the formal curriculum in schools but also informal learning—is part of this domain. Psychosocial Development Includes development of emotions, temperament, and social skills. Family, friends, the community, the culture, and the larger society are particularly central to the psychosocial domain. For example, cultural differences in “appropriate” sex roles or in family structures are part of this domain.

11. Childhood and Adulthood Are children more important than adults? Earlier research focused on child development; adulthood is now studied. Is childhood more important, influential, and determinative than adulthood? The answer is complex and depends in part on the developmental domain being considered. All age groups need support; more scientific study is needed.

12. Including All Kinds of People The challenge Identifying both universalities and differences and describing them in ways that simultaneously unify humanity and distinguish each individual The danger Drawing conclusions based on a limited group or, worse, to consider one’s own group normal and every other group abnormal (difference-equals- deficit error)

13. Including All Kinds of People Sexual orientation Illustrates a difference that was once assumed to be a deficit Led to bullying of LGBT classmates Is less likely to be perceived as deficit today due to activism, scientific data, and cultural change

14. Including All Kinds of People Important definitions Culture Ethnic group Race Socioeconomic status (SES) RYUHEI SHINDO/GETTY IMAGES

15. Widening Gap Between the Rich and the Poor at Different Ages

16. Finding the Balance In the science of human development Important to find the right balance between the universal and the particular Necessary to guard against simple conclusions across or within groups Key to remember that most categories are social constructions, not enduring divides

17. As Time Goes On Critical period Time when a particular type of developmental growth (in body or behavior) must happen for normal development to occur. Sensitive period Time when a certain type of development occurs more easily, although it may still happen later with more difficulty.

18. Patterns of Developmental Growth

19. As Time Goes On Ecological-systems approach (Bronfenbrenner) Each person is affected by many social contexts and interpersonal interactions. Nested levels surround individuals and affect them. Approach later named bioecological theory.

20. As Time Goes By Ecological Systems Microsystems Exosystems Macrosystems Mesosystem Chronosystem

21. The Ecological Model

22. As Time Goes By Historical context: Cohort Born within the same historical period Move through life together Experience same events, new technologies, and cultural shifts at the same ages Influences attitudes and behaviors

23. Can People Change? Plasticity Suggests abilities, personality, and other human characteristics can change over time Simultaneous incorporates two facts People can change over time New behavior depends partly on what has already happened Is evident in dynamic-systems approach

24. Dynamic-System Approach This classroom scene reflects the eagerness for education felt by many immigrants, the reticence of some boys in an academic context, and a global perspective (as demonstrated by the world map). These facets emerge from various systems—family, gender, and culture—and they have interacted to produce this moment. AP PHOTO/JIM MOORE

25. Using Scientific Methods Statistical measures often used to analyze research results Effect size Significance Cost-benefit analysis Odds ratio Factor analysis Meta-analysis

26. Using the Scientific Method Three basic types of research designs Observation The experiment The survey

27. Using the Scientific Method Scientific observation Requires researcher to record behavior systematically and objectively May be conducted in a naturalistic setting or a laboratory Is crucial to development of hypotheses

28. Using the Scientific Method Experiment Establishes causal relationships among variables Variables Independent variable Dependent variable Groups Experimental group Comparison group

29. How to Conduct an Experiment 1.Divide participants into two groups that are matched on important characteristics, especially the behavior that is the dependent variable on which this study is focused. 2.Give special treatment, or intervention (the independent variable), to one group (the experimental group). 3.Compare the groups on the dependent variable. If they now differ, the cause of the difference was probably the independent variable. 4.Publish the results.

30. Using the Scientific Method Survey Includes information collected from a large number of people by interview, questionnaire, or some other means Challenges Acquiring valid survey data is not easy. Some people lie, some change their minds. Survey answers are influenced by the wording and the sequence of the questions.

31. Did You Have Sexual Intercourse Before Age Thirteen? I Forgot? If this were the only data available, you might conclude that ninth- graders have suddenly become more sexually active than twelfth- graders. But we have 20 years of data—those who are ninth-graders now will answer differently by twelfth grade.

32. Studying Development Basic research designs Cross-sectional research Longitudinal research Cross-sequential research

33. Studying Development Which approach is best? Cross-sectional research: Most convenient, quickest, and least expensive way to study developmental change over time; does not always indicate processes of development Longitudinal research: Useful in studying development over many years; uncovers links that cross-sectional research does not; more time and resource intensive Cohort-sequential research: Allows disentanglement of age and historical context

34. Cautions and Challenges from Science Correlation and causation A correlation exists between two variables if one variable is more (or less) likely to occur when the other does Positive correlation Negative correlation Zero correlation Correlation is not causation!

35. Cautions and Challenges from Science Quantitative research Provides data that is numerical, and is best to compare children in different contexts and cultures Is easier to replicate, interpret, and verify Qualitative research Best captures the nuance of individual lives Reports information without being quantified

36. Vaccination and Autism Suspicion of science and federal government has led some parents not to vaccinate their child. Some parents believe that that certain childhood vaccinations cause autism spectrum disorder. What would you say to a parent who asked you if this is true? What advice would you give regarding childhood vaccination? ERPRODUCTIONS LTD/GETTY IMAGES

37. Ethics Each academic discipline and professional society involved in the study of human development has a code of ethics. In U.S., most educational and medical institutions have an Institutional Review Board

38. Ethical Safeguards Protection of research participants Most important safeguard ensures no harm occurs. Participants must understand and agree to research procedures (informed consent). Integrity of scientific study Methods and conclusions must promote accuracy, honesty, and truthfulness.

39. Science as a Way to Help Humankind The ultimate purpose of the science of human development is to help “all kinds of people, everywhere, of every age” live satisfying and productive lives.