Developmental theory has long emphasized the importance of linking perception, cognition, and action. Techniques designed to record the spatial and temporal characteristics of hand movements (i.e., "manual dynamics") present new opportunities to study the nature of these links across development by providing a window into how perceptual,…

The articles in this special issue of the "Journal of Cognition and Development" examine the cognitive development of children who are following typical and atypical developmental pathways. The articles offer a mixture of theory-based considerations, reviews of the literature, and new empirical data addressing fundamental aspects of…

Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

In this article the author describes challenges associated with integrating physiological measures of stress into developmental research, especially in the domains of memory and cognition. An initial critical challenge concerns how to define stress, which can refer to one or a series of events, a response, the consequence of that response, an…

Cognitive development is a cultural process. More experienced cultural members and the practices, institutions, and artifacts of the culture provide support and guidance for children as they develop knowledge and thinking skills. In this article, the authors describe the value that is added to our understanding of cognitive development when…

Longitudinal data analysis has long played a significant role in empirical research within the developmental sciences. The past decade has given rise to a host of new and exciting analytic methods for studying between-person differences in within-person change. These methods are broadly organized under the term "growth curve models." The…

This article introduces a promising new methodology called optical imaging. Optical imaging is used for measuring changes in cortical blood flow due to functional activation. The article outlines the pros and cons of using optical imaging for studying the brain correlates of perceptual, cognitive, and language development in infants and young…

"Little by little, the child develops," wrote an undergraduate in a friend's cognitive development class, and so, for the most part, it is. But what explains the U's of cognitive development? Namy, Campbell, and Tomasello and Cashon and Cohen take a standard approach to understanding U-shaped curves: as the product of a mix of different cognitive…

The articles featured in this issue make apparent the variety of perceptual and cognitive competencies that follow curvilinear developmental courses as well as the complexities inherent in accounting for such phenomena. What is revealed is the way in which a fit is achieved between organisms and the environments they occupy. Curvilinear…

As the articles in this issue attest, U-shaped curves in development have stimulated a wide spectrum of research across disparate task domains and age groups and have provoked a variety of ideas about their origins and theoretical significance. In the authors' view, the ubiquity of the general pattern suggests that U-shaped curves can arise from…

When a behavior disappears and then resurfaces, developmental psychologists typically look more closely at the behavior to figure out what is different before and after--that is, they increase the grain with an eye toward discovering how the system that generates that behavior has changed. But what ought to count as a U-shaped phenomenon? How…

The aim of this article is to introduce readers to an alternative way of applying U-shaped functions to understand development, especially cognitive development. In classical developmental applications, age is the abscissa; that is, in the fundamental equation B = f(A), some behavioral variable (B) plots as a U-shaped or inverted U-shaped function…

Interest in U-shaped development has itself undergone a U-shaped progression. Twenty-five years ago, interest in U-shaped development was high. This interest was evident at a 1978 conference in Tel Aviv on "U-shaped Behavioral Growth" that resulted in the publication of a book of the same title 4 years later (Strauss, 1982). The breadth…

The traditional view of development is stage-like progress toward increasing complexity of form. However, the literature cites many examples in which children do worse before they do better. A major challenge for developmental theory, therefore, is to explain both global progress and apparent regression. In this article, we situate U-shaped…