consensus on 17 goals for supporting individuals and ensuring equity and health in all countries (United Nations General Assembly, 2015). Sample goals include ending poverty in all its forms everywhere; improving nutrition, health, and well-being for all people; promoting education and lifelong learning opportunities; and achieving gender equality and empowering all women and girls. The goals are broad in scope, and reaching them will require the knowledge and skills of applied developmental scientist researchers and practitioners from many disciplines working in interdisciplinary teams (Gauvain, 2018).
What Do You Think?
What are some of the practical challenges a researcher might face in studying applied problems, such as risks to children’s health, how to advance education in underserved communities, or how to promote health and well-being in children of developing nations? ●
The Active Child: How Do Children Influence Their Own Development?
Children’s development is influenced by their genes and environment, but children also play an active role in guiding their own development. For example, Baby Joey smiles at each adult he passes by as his mother pushes his stroller in the park. Adults often respond with smiles, use “baby talk,” and make faces. Baby Joey’s actions, even simple smiles, influence adults, bringing them into close contact, making one-on-one interactions, and creating opportunities for learning. By engaging the world around them, thinking, being curious, and interacting with people and objects, infants and children are “manufacturers of their own development” (Flavell, 1992, p. 998).
The prevailing view among developmental scientists is that individuals are active contributors to their own development (Lerner, Agans, DeSouza, & Hershberg, 2014). Children are influenced by the physical and social contexts in which they live, but they also play a role in influencing their development by interacting with and changing those contexts (Elder, Shanahan, & Jennings, 2016). Children interact with and influence the people and things around them, creating experiences that influence their physical, cognitive, and emotional development. That is, they play an active role in influencing their own development.
Infants influence their own development by smiling at adults, making adults more likely to smile, use “baby talk,” and play with them in response.
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Continuities and Discontinuities: In What Ways Is Development Continuous and Discontinuous?
Some aspects of development unfold slowly and gradually over time, demonstrating continuous change. For example, children slowly gain experience and learn strategies to become quicker at problem solving (Siegler, 2016). Others are best described as discontinuous change, characterized by abrupt change. For example, puberty transforms children’s bodies into more adult-like adolescent bodies (Wolf & Long, 2016), infants’ understanding and capacity for language is qualitatively different from that of school-aged children (Hoff, 2015), and children make leaps in their reasoning abilities over the course of childhood, such as from believing that robotic dogs and other inanimate objects are alive to understanding that life is a biological process (Beran, Ramirez-Serrano, Kuzyk, Fior, & Nugent, 2011; Zaitchik, Iqbal, & Carey, 2014). As shown in Figure 1.2, a discontinuous view of development emphasizes sudden transformation, whereas a continuous view emphasizes gradual and steady changes.
Figure 1.2 Continuous and Discontinuous Development
Source: Adapted from End of the Game (2014) Child Development 101, History and Theory, https://endofthegame.net/2014/04/15/child-development-101-history-and-theory/3/
It was once believed that development was either continuous or discontinuous—but not both. Today, developmental scientists agree that development includes both continuity and discontinuity (Lerner et al., 2014). Whether a particular developmental change appears continuous or discontinuous depends in part on our point of view. For example, consider physical growth. We often think of increases in height as involving a slow and steady process; each month, an infant is taller than the prior month, illustrating continuous change. However, as shown in Figure 1.3, when researchers measured infants’ height every day, they discovered that infants have growth days and nongrowth days, days in which they show rapid change in height interspersed with days in which there is no change in height, illustrating discontinuous change (Lampl, Johnson, & Frongillo, 2001). In this example, monthly measurements of infant height suggest gradual increases, but daily measurements show spurts of growth, each lasting 24 hours or less. Thus, whether a given phenomenon, such as height, is described as continuous or discontinuous can vary depending on perspective. Most developmental scientists agree that some aspects of development are best described as continuous and others as discontinuous (Miller, 2016).
Figure 1.3 Infant Growth: A Continuous or Discontinuous Process?
Infants’ growth occurs in a random series of roughly 1-centimeter spurts in height that occur over 24 hours or less. The overall pattern of growth entails increases in height, but whether the growth appears to be continuous or discontinuous depends on our point of view.
Source: Figure 1 from Lampl, M., Veldhuis, J. D., & Johnson, M. L. (1992). Saltation and stasis: A model of human growth. Science, 258, 801–803. With permission from AAAS.
Thinking In Context 1.2
1 In what ways are your traits and abilities influenced by nature? How has nurture contributed to your development?
2 Can you identify ways in which you have changed very gradually over the years? Were there other times in which you showed abrupt change, such as physical growth, strength and coordination, thinking abilities, or social skills? In other words, in what ways is your development characterized by continuity? Discontinuity?
3 Identify examples of how a child might play an active role in his or her development. How do children influence the world around them?
Theories of Child Development
Over the past century, developmental scientists have learned much about how children progress from infancy through adolescence and into adulthood. Developmental scientists organize their observations to construct theories that explain how development unfolds. A theory is a way of organizing a set of observations or facts into a comprehensive explanation of how something works. Theories are important tools for compiling and interpreting the growing body of research in child development as well as determining gaps in our knowledge and making predictions about what is not yet known.
Effective theories pose specific explanations, or hypotheses, for a given phenomenon that can be tested by research. Scientists conduct research to find flaws in the hypothesis—not to “prove” that it is “correct.” A good theory is one that is falsifiable, or capable of generating hypotheses that can be tested and, potentially, refuted. As scientists conduct research and learn more about a topic, they modify their theories. Updated theories often give rise to new questions and new research studies, whose findings may further modify theories. The great body of research findings about child development has been organized into several theories to account for the developmental changes that occur in infancy, childhood, and adolescence.
Psychoanalytic Theories