18 Unit 1 Children and Families in Today’s World Copyright Goodheart-Willcox Co., Inc. Theories of Growth and Development Several researchers who studied children exten- sively have developed theories. A theory is a set of statements offered as a possible explanation for a phenomenon, such as child growth and develop- ment. Child development theories • describe changes (may also be called stages) over time within one or more areas of development • show changes among areas (domains) of development • explain why the changes occur Some theories deal with biology, others with the environment, and still others with both biology and the environment. Because the theories listed in Figure 1.9 cover many aspects of development, they are often referred to as the grand theories. Associated with these theories are the pioneering theorists whose works shape people’s knowledge of child development. Why are there so many theories? Why cannot just one theory be validated by research? Theorists experience the following problems: • Development is too broad and complex for one theorist to study all aspects of development. • Research is not completely objective. Theorists begin with their personal knowledge, interests, and hunches. Their hunches determine what questions they ask and how they set up their research. • New research has to begin with what is known based on theory. • New research relies on available research tools. Most of the child development theorists were doing their work before the time of computers or even calculators. Recording equipment was not available either, so all notes were handwritten. Technology, such as brain scans and computers, make a major difference in the ability to research child development. Even with the best of technology, however, research is a long and slow process. often discussed in separate chapters. This is so you can better understand each aspect. In reality, how- ever, all aspects are interrelated, or they interact in complex ways. People who work with children must under- stand how areas of growth and development affect one another. For instance, a teacher’s job is to improve children’s intellectual growth. If chil- dren come to school hungry or sleepy, however, they will not do well in learning activities. Stud- ies have shown that unless children have posi- tive feelings about themselves (social-emotional domain), they cannot devote the attention and energy needed for learning. Understanding these interrelationships improves the way people work with children. Figure 1.8 Motivation is a person’s desire to achieve or progress. What are some qualities of a motivated person?