History of Research in Developmental Psychology

This chapter summarizes the emergence and prominent features of a science of psychological development. Pioneering researchers established laboratories in Europe in the mid-nineteenth century to examine the significance of successive changes in the organism with the passage of time. American psychologists, many of whom had studied in the European laboratories, subsequently inaugurated similar efforts in the United States. Scientific theories and methods in the fledgling field were fostered by developments in experimental psychology, but also in physiology, embryology, ethology, and sociology. Moreover, organized efforts to provide information about development to parents, educators, and public policy specialists further propagated support for developmental science. The evolution of the field in its first century has provided a substantial platform for future developmental research.

The Road to Walking

Learning to walk is one of the great achievements in human development. An aim of this chapter is to describe the developmental progression of locomotion, ranging from the spontaneous leg kicks of fetuses to the seemingly superhuman abilities of Tarahumaran endurance runners. Our chief aim, however, is to use the development of walking as an exemplar and metaphor for understanding development more broadly. The century-old study of the ontogeny of walking—from the classic descriptions of motor milestones to the modern recognition of the importance of experience in all forms of locomotion—provides one of the clearest, empirically based illustrations of the pragmatic and theoretical issues, methodological advances and conceptual pitfalls, and general principles and processes of development that is available to psychology.

Computational Models in Developmental Psychology

Computational modeling implements developmental theory in a precise manner, allowing generation, explanation, integration, and prediction. Several modeling techniques are applied to development: symbolic rules, neural networks, dynamic systems, Bayesian processing of probability distributions, developmental robotics, and mathematical analysis. The relative strengths and weaknesses of each approach are identified and examples of each technique are described. Ways in which computational modeling contributes to developmental issues are documented. A probabilistic model of the vocabulary spurt shows that various psychological explanations for it are unnecessary. Constructive neural networks clarify the distinction between learning and development and show how it is possible to escape Fodor’s paradox. Connectionist modeling reveals different versions of innateness and how learning and evolution might interact. Agent-based models analyze the basic principles of evolution in a testable, experimental fashion that generates complete evolutionary records. Challenges posed by stimulus poverty and lack of negative examples are explored in neural-network models that learn morphology or syntax probabilistically from indirect negative evidence.

Spatial Development

This chapter is a selective review of spatial development, stressing several points. First, we suggest that spatial development can be usefully considered to have two strands: (a) the development of intraobject (or intrinsic) representations along with the ability to transform them (e.g., in mental rotation) and (b) the development of interobject (or extrinsic) representations and the ability to use them to navigate. Second, we argue that both lines of development begin from strong starting points, but also undergo considerable development. They are far from innately specified, nor do they have a modular architecture. Third, we discuss the amplification of spatial skills by human symbolic capabilities, including language, use of maps and models, and gesture. Fourth, we identify areas where research is lacking, most notably the formal description of intraobject skills and the charting of their normative development, the exploration of the sources of individual differences in navigation-relevant skills, and the applications of research to education.

Moral Development

This chapter describes moral judgment development through the lens of social domain theory. Morality, or individuals’ concepts of justice, welfare, and rights, is seen as a distinct system or organized domain of social knowledge that develops separately from concepts of social conventions and personal issues; these concepts are constructed from children’s differentiated social interactions and social experiences. In this chapter, basic theoretical propositions of social domain theory and methods used to test those propositions are described, and then relevant empirical research is reviewed. The chapter highlights how children’s understanding and interpretation of their social worlds are elaborated and change from infancy through adolescence. The complexity and diversity of social life is described as entailing a consideration of moral concepts as informed by informational assumptions and knowledge of regularities in the affective consequences of different events. It is also considered in terms of the coexistence of and coordination with other social knowledge domains.

Cognitive Development

In this overview, I focus on contemporary research and theory related to five “truths” of cognitive development: (1) cognitive development proceeds as a result of the dynamic and reciprocal transaction of endogenous and exogenous factors; (2) cognitive development involves both stability and plasticity over time; (3) cognitive development involves changes in the way information is represented, although children of every age possess a variety of ways to represent experiences; (4) children develop increasing intentional control over their behavior and cognition; and (5) cognitive development occurs within a social context. Cognitive development happens at a variety of levels, and developmental scientists are becoming increasingly aware of the need to be cognizant of this and the interactions among the various levels to produce a true developmental science.

Development of Face-Processing Ability in Childhood

Faces are arguably the most significant visual stimuli in children’s social environment. Much of children’s adaptive social functioning relies on their success in extracting crucial information from the faces of their social partners. In this chapter, we provide an exhaustive review of both classic and current research on the development of face processing from infancy to adolescence. The topics covered range from the processing of facial attractiveness to face categorization and recognition. In addition to behavioral studies, we also review the most recent developmental neuroscience findings regarding the neural mechanisms underlying the development of face-processing ability. Major theoretical issues and future directions of research are discussed.

The History of Intelligence

The psychometric and developmental traditions obscure what they have in common: understanding human intelligence in all of its manifestations. Each tradition tends to take its theoretical construct as universally relevant. The cognitive history of the twentieth century shows huge IQ gains from one generation to another. Those who follow Spearman discount IQ gains unless they are factor invariant across generations—for example, manifest the enhancement of g. The developmental tradition can accommodate altered cognition over time because it emphasizes mutual interaction between characteristics of persons and the environments in which they are situated. We use IQ gains to reconstruct the history of cognitive skills; and introduce concepts like “habits of mind” and “the mind as a muscle” and “cognitive priorities” to unify history, developmental psychology, and psychometrics. We draw implications for education and interventions, maximizing cognitive ability throughout life, genes and environment, and group differences.

Symbols and Symbolic Thought

This chapter explores the development of symbol use and symbolic thought across diverse domains (gesture, linguistic, pretense, and the material artifacts of models, pictures, maps, and video). The chapter begins with a clarification of different conceptualizations of central theoretical constructs. Then, evidence to support major theoretical claims in the field is considered. A number of themes emerge from these findings. There is clear evidence that for all domains the onset of symbolic insight is based on solid perceptual, cognitive, learning, and social-cognitive foundations. The importance of social supports from expert symbol users was also evident. New proposals that link symbolic knowledge to the development of consciousness and the uniquely human motive to share promise to generate exciting new developments in this field.

Speech Perception in Infancy

We discuss the development of speech perception and its contribution to the acquisition of the native language(s) during the first year of life, reviewing recent empirical evidence as well as current theoretical debates. We situate the discussion in an epigenetic framework in an attempt to transcend the traditional nature/nurture controversy. As we illustrate, some perceptual and learning mechanisms are best described as experience-expectant processes, embedded in our biology and awaiting minimal environmental input, while others are experience-dependent, emerging as a function of sufficient exposure and learning. We argue for a cascading model of development, whereby the initial biases guide learning and constrain the influence of the environmental input. To illustrate this, we first review the perceptual abilities of newborn infants, then discuss how these broad-based abilities are attuned to the native language at different levels (phonology, syntax, lexicon etc.).