INTRODUCTION
Understanding is often accomplished through a sequential process of analysis followed by synthesis: we tear things apart, scrutinize the pieces in relative isolation, and only then begin to explore how the pieces interact to comprise a whole. Research on human development is now emerging from a protracted period of analysis during which various aspects of human function were studied one piece at a time. The worst excesses of this period, including our fascination with genetic determinism and extreme domain specificity, are now considered untenable, and interest has shifted to the complicated ways in which processes at cultural, social, cognitive, neural, and molecular levels of analysis operate together to yield human behavior and human development. The aim of this volume is to showcase outstanding examples of this new synthesis and, by doing so, to herald the birth of a new, more ecumenical discipline: ādevelopmental social cognitive neuroscience.ā
The birth of this new developmental discipline followed quickly on the heels of its immediate predecessorāsocial cognitive neuroscience, which also aimed at identifying the neural bases of socioemotional behavior (see, for example, Ochsner & Liebermann, 2001), but did so without the signature ontogenetic emphasis that marks the newer work featured in this volume. Since 2001, nondevelopmental research in social cognitive neuroscience has appeared regularly in leading journals, such as Science and Nature, and has been collected in numerous volumes and special issues. Among the many well-publicized findings are reports concerning the neural correlates of sympathy, moral reasoning, theory of mind, and the evaluation of socially relevant stimuli (faces, persons vs. objects, biological motion, etc.). These demonstrated neural correlates, together with research on infant behavior and rapid advances in developmental evolutionary psychology (e.g., Bjorklund & Pellegrini, 2002), were seen by many to provide converging evidence that human beings are born with a predisposition to acquire considerable socio-emotional competence very early in life.
What was largely missing from this new social cognitive neuroscience literature, however, was an account of how all of these well-established relations between manifest behaviors and their neural underpinnings actually came into being. No one any longer doubts that young persons are born with something of a biologically based head start in accomplishing their important life tasksāgenetic resources, if you will, that are exploited differently in different contexts. Nevertheless, it is also true that socially relevant neural functions develop slowly during childhood, and that this development is owed to various complex interactions among genes, social and cultural environments, and childrenās own behavior. A key challenge lies in finding appropriate ways of describing these complex interactions and the way in which they unfold in real developmental time. This is the challenge that motivates research in developmental social cognitive neuroscience.
The concatenation of three adjectives (i.e., ādevelopmental,ā āsocial,ā and ācognitiveā) and one prefix (āneuro-ā) required to describe the scope of this new science, while admittedly a mouthful, does more than simply work to rally a crowd of historically distinct scholars together under a common banner. Rather, it signals a new, multidimensional characterization of a once-fractured subject matterāone in which human beings are newly viewed as dynamic organisms that must be described at multiple, interacting levels of analysis. On this view, it is arbitrary and potentially misleading simply to study in isolation some single aspect of a human being at one point during the lifespan. We would be mistaken, for example, to assume that cognition can be adequately characterized independently of the sociocultural context in which it occurs. Context may not be everything, but it certainly is a lotāa fact that seems to be true at all levels of analysis, from the protein-coding functions of specific genes to the characteristics of neural systems, to the subjective interpretation of arousal. At all levels of analysis, our subject matter is best understood, in the views of those who have contributed to this volume, as a dynamic event, conditioned by (but not determined by) history, and unfolding in time and space. There is little use nowadays for simple-and-sovereign accounts according to which human behavior is āexplainedā by exclusive reference to any one of a number of supposed causes, whether these be Piagetian stages, childrenās ātheories,ā mental modules, neural activation in some region of cortex, or the presence of particular genetic polymorphisms. In most cases, these so-called ācausesā are merely correlates or constituent parts of the phenomena in question, and, more often than not, they are simply alternative descriptions of the same phenomena at different levels of analysis. From the perspective of the contributors to this volume, the shared hope is that all such piecemeal descriptions will eventually find their proper place in a far more complex characterization of overall human growth and development.
THE PRESENT VOLUME
The contributors to this volume include both social cognitive neuroscientists who recognize the importance of human development and developmental psychologists who appreciate the promise and potential of a social cognitive neuroscience approach. Collectively, their contributions illustrate the latest, best work in this emerging field. At the same time, however, these multidisciplinary efforts and collaborations are not without their risks and possible pitfalls, and we have also included contributors who reflect critically on this new enterprise in an effort to foster its early development.
The first set of chapters concern the typical and atypical development of social cognition in childhood. One of the most exciting recent advances in social cognitive neuroscience has been the discovery of mirror neurons in monkeys by Rizzolatti, Gallese, and colleagues (e.g., see Rizzolatti, Fogassi, & Gallese, 2001). Gallese and Rochat (Chapter 2) review this work and suggest that the mirror neuron system plays a key, foundational role in the ontogeny of social cognition, providing us with a prereflexive understanding of othersā actions as these actions are mapped onto our own action repertoires. Whereas Gallese and Rochat emphasize the conservation of the mirror neuron system during primate evolution, Moore and Barresi (Chapter 3) focus on the way in which self-other matching develops in human infants. They review recent research suggesting that infantsā representations of intentional action are initially quite limited (e.g., restricted to particular actions) and are only gradually, through social interactions, integrated into more complex characterizations of independent intentional agents.
One aspect of social cognition that develops substantially during the course of childhood is childrenās understanding of their own and othersā mental statesātheir theory of mind. Benson and Sabbagh (Chapter 4) address the possible neural changes associated with the development of an understanding of the intentional or representational character of mental states. Their approach is to consider the possible roles of executive functionāand by extension, prefrontal cortexāin childrenās developing theory of mind. As Benson and Sabbagh show, it is now well established that theory of mind and executive function are closely related, but the nature of this relation is still a matter of debate.
Cunningham and Zelazo (Chapter 5) also address neural changes associated with both theory of mind and executive function, in the context of their work on the iterative reprocessing of information via neural circuits involving prefrontal cortex. In this chapter, they consider the implications of this work for the early development of affective experience and its regulation.
The last two chapters in this section are concerned, in large part, with the atypical development of social cognition that is characteristic of the neurodevelopmental disorder of autism. Perlman, Vander Wyk, and Pelphrey (Chapter 6) present a new hypothesis regarding the neural changes involved in the development of two interrelated aspects of social cognition, social perception (i.e., the initial stages of evaluating intentions and dispositions of others), and action understanding (i.e., the appreciation of othersā actions in terms of mental states). They then discuss how early insults to the brain mechanisms involved in these processes might influence the subsequent development of higher-order social cognition, including theory of mind. Baron-Cohen (Chapter 7) focuses more squarely on autism and, in particular, he reviews the evidence for his empathizing-systemizing theory, according to which autism can be characterized in terms of below average empathy and average or above-average systemizingāthe drive to analyze or construct systems.
The second set of chapters addresses the developmental changes taking place in later childhood and adolescence, including changes in impulsivity, novelty seeking, risk taking, self-awareness, and executive function. Pfeifer, Dapretto, and Lieberman (Chapter 8) focus on evaluative self-knowledge, which undergoes considerable changes during adolescence, and they summarize the first set of imaging studies meant to examine the neural basis of self-referential processing in children and adolescents. On the basis of their findings, they describe a new developmental model of the neural systems supporting self-evaluation.
Ernst and Hardin (Chapter 9) also present a model of the neurodevelopmental changes occurring during adolescence, with a special focus on affective decision making. They show how their triadic model of decision making, which includes systems associated with approach, avoidance, and executive function, can account for an emerging corpus of data on reward-related behavior in adolescence, and they use the model to generate predictions for future research.
The potentially problematic behaviors associated with adolescence are also considered by Baird (Chapter 10), who refers to early adolescence as āthe terrible twelves.ā By drawing a parallel between behavioral changes in early childhood and early adolescence, she provides a neurobiological account of noncompliant behavior that may shed common light on behavior during both developmental periodsāand may help parents to view their teenagersā behavior with more compassion.
Leijenhorst and Crone (Chapter 11) address an apparent paradox in the literature on adolescent decision-making: there is evidence that risk taking increases during adolescence even though risk tak...