SUMMARY

1. The study of human development is a science that seeks to understand how people change or remain the same over time. As a science, it begins with questions and hypotheses and then gathers empirical data. Researchers draw conclusions based on the evidence. Replication confirms, modifies, or refutes the conclusions of a scientific study.

2. Nature (genes) and nurture (environment) always interact, affected by every human characteristic. Neuroscience has discovered differential susceptibility—that certain genes increase or decrease the likelihood that a child will be affected by the environment.

3. Development is divided into three domains—biological, cognitive, and psychosocial, or body, mind, and social world. Every domain is involved in every characteristic, which makes the science of human development always multidisciplinary.

4. The assumption that growth is linear and progress is inevitable has been replaced by the idea that both continuity (sameness) and discontinuity (sudden shifts) are part of every life, that gains and losses are apparent at every age. Development is multi-directional.

5. Time is a crucial variable in studying human development. A critical period is a time when something must occur to ensure normal development or the only time when an abnormality might occur. Often a particular development can occur more easily—but not exclusively—at a particular time, called a sensitive period.

6. Urie Bronfenbrenner’s ecological-systems approach notes that each of us is situated within larger systems of family, school, community, and culture, as well as part of a historical cohort. Changes within a person, or changes in the context, affect all other aspects of the system. Development is multi-contextual.

7. Socioeconomic status (SES) is an important influence on human development, affecting a person’s opportunities, health, and even abilities at every stage.

8. Culture includes beliefs and patterns; ethnicity refers to ancestral heritage. These two often overlap, but they are not identical. Race is a social construction, sometimes mistakenly thought to be biological.

   45

9. Developmentalists try to avoid the difference-equals-deficit error. Differences may be alternate ways to think or act, not necessarily less beneficial than the familiar ways. Development is multi-cultural.

10. Throughout life, human development is plastic. Plasticity emphasizes that it is possible for brains and behaviors to change over time, although it is also true that early experiences affect later development.

11. Psychoanalytic theories stress the legacy of childhood. According to Freud, conflicts associated with children’s erotic impulses have a lasting impact on adult personality. Erikson thought that the resolution of each crisis affects later life and that new crises appear in adulthood.

12. Behaviorists, or learning theorists, believe that scientists should study observable and measurable behavior. Behaviorism emphasizes conditioning, in which one stimulus may be associated with another (classical conditioning) or reinforcement and punishment may guide future behavior (operant conditioning).

13. Cognitive theorists believe that thoughts and beliefs powerfully affect attitudes, actions, and perceptions. Piaget proposed four age-related periods of cognition. Information processing focuses on each aspect of cognitive input, processing, and output.

14. Humanism emphasizes the potential of humankind. For example, Maslow proposed a hierarchy of needs, which could lead to self-actualization.

15. Evolutionary theory contends that genes have fostered survival and reproduction of the human species for tens of thousands of years. Those genes continue to influence human behavior today, in alloparenting, attachment, and male/female behavior.

16. Commonly used research methods are scientific observation, the experiment, and the survey. Each can provide insight and discoveries that were not apparent before the research, although no method is perfect.

17. A challenge for developmentalists is to study change over time. Methods include cross-sectional, longitudinal, and cross-sequential research.

18. A correlation shows that two variables are related. However, it does not prove that one variable causes the other.

19. Ethical behavior is crucial in all the sciences. Not only must participants be protected and data kept confidential (primary concerns of IRBs), but results must be fairly reported and honestly interpreted.

20. The most important ethical question is whether scientists are designing, conducting, analyzing, publishing, and applying the research that is most critically needed. This is a challenge for the next generation of developmentalists.