The concept of development forms the backbone of modern behavioral science. Psychiatric practitioners and behavioral scientists are concerned primarily with change, and developmental psychology is the scientific study of the structure, function, and processes of systematic change across the life span. Even systems of classification of behavior (including psychiatric nosology) take into account not only contemporaneous features and formal similarities among current symptoms but also past qualities, immediate consequences, and long-term outcomes.
Whereas developmental psychology is concerned with species-typical patterns of systematic change (and central tendencies of the species), the emerging discipline of developmental psychopathology is concerned with individual differences and contributes greatly to our understanding of childhood disorders.
The organizing framework of developmental psychopathology is a movement toward understanding the predictors, causes, processes, courses, sequelae, and environmental symbiosis of psychiatric illnesses in order to discover empirically effective forms of treatment and prevention. This movement is girded in a developmental framework that integrates knowledge from multiple disciplines (eg, psychobiology, neuroscience, cognitive psychology, social psychology) and levels of analysis (eg, neuronal synapses, psychophysiologic responses, mental representations, motor behaviors, personality patterns). The relationship between developmental psychology and developmental psychopathology is reciprocally influential: The study of normal development gives context to the analysis of aberrations, and the study of psychopathology informs our understanding of normative development.
A developmental orientation forces a scholar to ask questions that move beyond the prevalence and incidence of disorders. Table 1-1 lists some of these questions.
The Orthogenetic Principle
Human growth is not linear. Behavioral and psychological change is not marked merely by quantitative advances or declines. The organizational perspective on development offers a powerful theoretical framework for depicting the organism as an integrated system with hierarchically ordered subsystems and for understanding change as a progression of qualitative reorganizations within and among subsystems. The human being is a coherent integration of neural, physiologic, hormonal, affective, information-processing, mental representational, behavioral, and social subsystems. Change occurs both within these subsystems and in the relations among them.
The orthogenetic principle proposes that development moves from undifferentiated and diffuse organization toward greater complexity, achieved through both differentiation and consolidation within and across subsystems. The newborn infant is relatively undifferentiated in response patterns, but through development this infant achieves greater differentiation (and less stereotypy) of functioning. Each period of development is characterized by adaptational challenges resulting from environmental demands (eg, a mother who has become unwilling to breast-feed) and from emerging internal influences across subsystems (eg, growing recognition of the self as able to exert control). The challenges are best conceptualized not as mere threats to homeostasis; rather, change and the demand for adaptation define the human species, and challenges push the individual toward development. The inherent adaptational response of the species is toward mastery of new demands. The mastery motive is as yet unexplained by science, although it is paradigmatic of the human species.
Thus development is characterized by periods of disruption in the homeostasis of the organism brought on by a new challenge, followed by adaptation and consolidation until the next challenge is presented. The adaptive child uses both internal and external resources to meet a challenge. Successful adaptation is defined as the optimal organization of behavioral and biological systems within the context of current challenges. Adaptation requires the assimilation of past organizational structures to current demands as well as the generation of new structures equipped to meet the demands.
Consider the toddler who is confronted by an environment that becomes less indiscriminately giving (eg, a mother who needs to feed her toddler on a schedule). The toddler may respond initially with temper tantrums to indicate his or her displeasure and needs, but tantrums evolve into verbal communication as the toddler learns how to achieve desired outcomes most efficiently. Thus environmental challenge and internal chaotic responses (eg, temper tantrums) may be steps in the orthogenesis of language.
Piaget described two types of change: assimilation, which involves incorporation of the challenge into existing organizational structures (eg, an infant might treat all adults as the same kind of stimulus); and accommodation, which involves reorganization of the organism’s structures to meet the demands of the environment (eg, a developing infant learns to discriminate among adults and to respond differently to different adults) (see “Organismic Theory” section later in this chapter). Accommodation is more complex than assimilation, but successful adaptation requires a balance of assimilation and accommodation.
Maladaptation, or incompetence in responding to challenge, may be characterized by the inadequate resolution of developmental challenges (as in the psychoanalytic concept of fixation). Maladaptation may be evidenced by developmental delays or lags, such as the continuing temper tantrums of an emotionally dysregulated child beyond the period when such behavior is normative. At any phase, the organism will seek some form of regulation and functioning, even if it is not advantageous for future development. Thus the child’s tantrums might serve to regulate both a complex external environment of marital turmoil and an internal environment of stress. However, nonoptimal regulation will prevent or hamper the individual from coping with the next developmental challenge. Continuing the example of the dysregulated child, the repetitive pattern of anger may lead to poor peer relations, which prevent the child from acquiring new social skills through friendships.
Sometimes apparently effective responses to a particular challenge lead to maladaptation at a more general level. Consider a toddler who responds to the withdrawal of a mother’s undivided attention by ignoring her. Although this pattern of response may mean calmer evenings temporarily, the toddler will be ill equipped to respond to other challenges later in development. Consistent social withdrawal may cause the child to fail to acquire skills of assertion; however, continued ignoring of the mother may lead to a phenotypically distinct response in the future (eg, depression in adolescence). Thus the orthogenetic principle calls to mind the functioning of the entire organism (not merely distinct and unrelated subsystems) and the readiness of that organism to respond to future challenges.