Introduction Developmental theory has changed greatly over time. The theories of societies at various times in history have emphasized different aspects of development. The Puritans of the sixteenth and seventeenth centuries, for example, focused on the moral development of the child; they believed that Original Sin was inherent in children and that children had to be sternly disciplined to make them morally acceptable. In contrast to this view was the developmental theory of the eighteenth century French philosopher Jean-Jacques Rousseau, who held that children were born good and were then morally corrupted by society. Sigmund Freud was interested in psychosexual development and in mental illness; his work therefore focused on these areas. John B. Watson, B. F. Skinner, and Albert Bandura worked during a period when the major impetus in psychology was the study of learning; not surprisingly, this was the focus of their work.
As developmental theorists worked intently within given areas, they often arrived at extreme positions, philosophically and scientifically. For example, some theorists focused on the biology of behavior; impressed by the importance of “nature” (genetic or other inherited sources) in development, they may have neglected “nurture” (learning and other resources received from the parents, world, and society). Others focused on societal and social learning effects and decided that nurture was the root of behavior; nature has often been relegated to subsidiary theoretical roles in physiological and anatomical development. Similar conflicts have arisen concerning developmental continuity or discontinuity, the relative activity or passivity of children in contributing to their own development, and a host of other issues in the field.
These extreme positions would at first appear to be damaging to the understanding of development; however, psychologists are now in a position to evaluate the extensive bodies of research conducted by adherents of the various theoretical positions. It has become evident that the truth, in general, lies somewhere in between. Some developmental functions proceed in a relatively stepwise fashion, as Jean Piaget or Freud would hold; others are much smoother and more continuous. Some development results largely from the child’s rearing and learning; other behaviors appear to be largely biological. Some developmental phenomena are emergent processes (any process of behavior or development that was not necessarily inherent in or predictable from its original constituents) of the way in which the developing individual is organized, resulting from both nature and nurture in intricate, interactive patterns that are only beginning to be understood. These findings, and the therapeutic and educational applications that derive from them, are comprehensible only when viewed against the existing corpus of developmental theory. This corpus in turn owes its existence to the gradual construction and modification of developmental theories of the past.
Theoretical Questions and Properties Theoretical perspectives on development derive from a wide variety of viewpoints. Although there are numerous important theoretical issues in development, three questions are central for most theories. The first of these is the so-called nature-nurture question, concerning whether most behavioral development derives from genetics or from the environment. The second of these issues is the role of children in their own development: are children active contributors to their own development, or do they simply and passively react to the stimuli they encounter? Finally, there is the question of whether development is continuous or discontinuous: Does development proceed by a smooth accretion of knowledge and skills, or by stepwise, discrete developmental stages? Perspectives within developmental psychology represent very different views on these issues.
Useful developmental theories must possess three properties. They must be parsimonious, or as simple as possible to fit the available facts. They must be heuristically useful, generating new research and new knowledge. Finally, they must be falsifiable, or testable. A theory that cannot be tested can never be shown to be right or wrong. Developmental theories can be evaluated in terms of these three criteria.
Psychodynamic Theories Arguably, the oldest developmental theoretical formulation in use is the psychodynamic model, which gave rise to the work of Erik H. Erikson and Carl Jung, and has as its seminal example, the theory of Sigmund Freud. Freud’s theory holds that all human behavior is energized by dynamic forces, many of which are consciously inaccessible to the individual. There are three parts to the personality in Freud’s formulation: the id, which emerges first and consists of basic, primal drives; the ego, which finds realistic ways to gratify the desires of the id; and the superego, the individual’s moral conscience, which develops from the ego. A primary energizing force for development is the libido, a psychosexual energy that invests itself in different aspects of life during the course of development. In the first year of life (Freud’s oral stage), the libido is invested in gratification through oral behavior, including chewing and sucking. Between one and three years of age (the anal stage), the libido is invested in the anus, and the primary source of gratification has to do with toilet training. From three to six years, the libido becomes invested in the genitals; it is during this phallic stage that the child begins to achieve sexual identity. At about six years of age, the child enters latency, a period of relative psychosexual quiet, until the age of twelve years, when the genital stage emerges and normal sexual love becomes possible.
Freud’s theory is a discontinuous theory, emphasizing stage-by-stage development. The theory also relies mainly on nature, as opposed to nurture; the various stages are held to occur across societies and with little reference to individual experience. The theory holds that children are active in their own development, meeting and resolving the conflicts that occur at each stage.
The success of psychodynamic theory has been questionable. Its parsimony is open to question: There are clearly simpler explanations of children’s behavior. The falsifiability of these ideas is also highly questionable because the theories are quite self-contained and difficult to test. Psychodynamic theory, however, has proven enormously heuristic—that is, having the property of generating further research and theory. Hundreds of studies have set out to test these ideas, and these studies have significantly contributed to developmental knowledge.
Behaviorist Theories In contrast to psychodynamic theories, the behaviorist theories pioneered by John B. Watson and B. F. Skinner hold that development is a continuous process, without discrete stages, and that the developing child passively acquires and reflects knowledge. For behaviorists, development results from nurture, from experience, and from learning, rather than from nature. The most important extant behaviorist theory is the
social learning theory of Albert Bandura, which holds that children learn by watching others around them and imitating others’ actions. For example, Bandura demonstrated that children were far more inclined to commit violent acts (toward a toy) if someone else, particularly an adult, committed the acts first. The children were especially disposed to imitate if they perceived the acting individual as powerful or as rewarded for his or her violent actions.
Organic Lamp Theories The behaviorist theories are relatively parsimonious and heuristic. They are also testable, and it has been shown that, although many of the findings of the behaviorists have stood the test of time, there are developmental findings that do not fit this framework. To understand these findings, one must turn to the so-called organic lamp theories. This term comes from the fact that within these theories, children are seen as active contributors to their own development, and certain developmental processes are held to be “emergent”: As fuel combusts to produce heat and light in a lamp, hereditary and environmental factors combine in development to produce new kinds of behavior. This framework was pioneered by Kurt Goldstein and Heinz Werner, but the most significant extant organic lamp theory is the cognitive development theory of Jean Piaget.
Piaget’s Contributions Piaget’s theory involves a discontinuous process of development in four major stages. The sensorimotor stage (birth to two years) is followed by the preoperational stage (two to seven years), the concrete operational stage (seven years to adolescence), and the formal operational stage (adolescence to adulthood). During the sensorimotor stage, the child’s behavior is largely reflexive, lacking coherent conscious thought; the child learns that self and world are actually different, and that objects exist even when they are not visible. During the preoperational stage, the child learns to infer the perspectives of other people, learns language, and discovers various concepts for dealing with the physical world. In the concrete operational stage, the ability to reason increases, but children still cannot deal with abstract issues. Finally, in formal operations, abstract reasoning abilities develop. The differences among the four stages are qualitative differences, reflecting significant, discrete kinds of behavioral change.
Piaget’s theory is not entirely accurate; it does not apply cross-culturally in many instances, and children may, under some experimental circumstances, function at a higher cognitive level than would be predicted by the theory. In addition, some aspects of development have been shown to be more continuous in their nature than Piaget’s ideas would indicate. Yet Piaget’s formulation is relatively parsimonious. The various aspects of the theory are readily testable and falsifiable, and the heuristic utility of these ideas has been enormous. This theory has probably been the most successful of the several extant perspectives, and it has contributed significantly to more recent advances in developmental theory. This progress includes the work of James J. Gibson, which emphasizes the active role of the organism, embedded in its environment, in the development of perceptual processes; the information-processing theories, which emphasize cognitive change; and the ethological or evolutionary model, which emphasizes the interplay of developmental processes, changing ecologies, and the course of organic evolution.
Modern-Day Applications Developmental theory has been important in virtually every branch of medicine and education. The psychoanalytic theories of Freud were the foundation of psychiatry and still form a central core for much of modern psychiatric practice. These theories are less emphasized in modern clinical psychology, but the work of Freud, Erikson, Jung, and later psychodynamicists is still employed in many areas of psychotherapy.
The behavioristic theories have proved useful in the study of children’s learning for educational purposes, and they have considerable relevance for social development. An example is seen in the area of media violence. Bandura’s work and other research stemming from social learning theory have repeatedly demonstrated that children tend to imitate violent acts that they see in real life or depicted on television and in other media, particularly if the individuals who commit these acts are perceived as powerful or as rewarded for their actions. Although this is disputed, especially by the media, most authorities are in agreement that excessive exposure to televised violence leads to real-world violence, largely through the mechanisms described by social learning theorists. Social learning theory has contributed significantly to an understanding of such topics as school violence, gang violence, and violent crime.
Interplay of Nature Versus Nurture The organic lamp views have provided developmentalists with useful frameworks against which to understand the vast body of developmental data. Work within the Piagetian framework has shown that both nature and nurture contribute to successful development. One cannot, for example, create “superchildren” by providing preschoolers with college-level material. In general, they are simply not ready as organisms to cope with the abstract thinking required. On the other hand, the work of researchers on various Piagetian problems has shown that even very young children are capable of complex learning.
Organic lamp theory has demonstrated the powerful interplay between biological factors and the way in which children are reared. An example is seen in the treatment of Down syndrome, a chromosomal condition that results in mental retardation. The condition occurs when there are three chromosomes, rather than two, at the twenty-first locus. Clearly, this is a biological condition, and it was believed to be relatively impervious to interventions that come from the environment. It has now been shown, however, that children afflicted with Down syndrome develop much higher intelligence when reared in an intellectually stimulating environment, as opposed to the more sterile, clinical, determined environments typically employed in the past. The child’s intellect is not entirely determined by biology; it is possible to ameliorate the biological effects of the syndrome by means of an environmental intervention. This type of complex interplay of hereditary and environmental factors is the hallmark of applied organic lamp theory.
The most important application of developmental theory generally, however, lies in its contribution to the improved understanding of human nature. Such an understanding has considerable real-world importance. For example, among other factors, an extreme faith in the nature side of the nature-nurture controversy led German dictator Adolf Hitler to the assumption that entire races were, by their nature, inferior and therefore should be exterminated. His actions, based on this belief, led to millions of human deaths during World War II. Thus, one can see that developmental theories, especially if inadequately understood, may have sweeping applications in the real world.
Bibliography
Dowling, John E. The Great Brain Debate: Nature or Nurture? Princeton: Princeton UP, 2007. Print.
Gollin, Eugene S., ed. Developmental Plasticity: Behavioral and Biological Aspects of Variations in Development. New York: Academic Press, 1981. Print.
Lerner, Richard M. On the Nature of Human Plasticity. New York: Cambridge UP, 1984. Print.
Miller, Patricia H. Theories of Developmental Psychology. 4th ed. New York: Worth, 2002. Print.
Piaget, Jean. Biology and Knowledge. Chicago: U of Chicago P, 1971. Print.
Pickren, Wade E., Donald A. Dewsbury, and Michael Wertheimer. Portraits of Pioneers in Developmental Psychology. New York: Psychology Press, 2012. Print.
Revelle, Glenda. "Applying Developmental Theory and Research to the Creation of Educational Games." New Directions for Child & Adolescent Development 2013.139 (2013): 31–40. Print.
Shaffer, David Reed. Developmental Psychology: Childhood and Adolescence. 7th ed. Belmont: Wadsworth, 2007. Print.
Siegler, Robert S. Emerging Minds: The Process of Change in Children’s Thinking. New York: Oxford UP, 1998. Print.
Thompson, Dennis, John D. Hogan, and Philip M. Clark. Developmental Psychology in Historical Perspective. Malden: Wiley, 2012. Print.
