Advanced Review The development of emotion Peter J. Marshall∗ Given that they are responsible for much of the meaning that we attribute to our existence, emotions could be said to have a central role in the psychological life of humans. But given this fundamental level of significance, the construct of emotion remains poorly understood, with the field of emotion research being full of conflicting definitions and opposing theoretical perspectives. In this review, one particular aspect of research into emotion is considered: the development of emotion in infancy and early childhood. The development of the emotional life of the child has been the focus of a vast amount of research and theorizing, so in a brief review it is only possible to scratch the surface of this topic. Rather than any attempt at a comprehensive account, three perennial questions in theorizing and research on early emotional development will be considered. First, what develops in emotional development? Second, what is the relation of cognitive development to emotional development? Third, how has the study of early individual differences in emotion expression typically been approached? In relation to the first question, four theoretical approaches to emotional development are described. For the second question, the focus is on the relation of self-awareness to the development of emotion. Finally, for the third question, the use of temperament theory as a framework for understanding individual differences in emotion expression is examined. 2010 John Wiley & Sons, Ltd. WIREs Cogn Sci 2010 1 417–425 n the space of the first 3 years of life, the difficult questions which lie at the intersection of the Ideveloping human undergoes very dramatic changes developmental, affective, and cognitive sciences. Of across all domains of development. Physically, a these questions, three will be briefly considered in typical infant doubles its length and quadruples its this selective review: (1) What develops in emotional weight. Among many other developments, he or she development? (2) How does emotional development typically also develops the capacities to independently relate to cognitive development? (3) How has the locomote, to use and understand spoken language, study of individual differences in infant emotion and in the process become an active participant typically been approached? in his or her cultural community. In everyday observations of children’s psychological development, one other particularly striking change concerns the WHAT DEVELOPS IN EMOTIONAL emotional life of the infant. As a neonate, an infant DEVELOPMENT? appears to have an organized but relatively limited range of emotional expressions from contentment Above and beyond the description of which kinds and interest to distress. By the third birthday, of emotions may be observed in infancy and the the emotional repertoire of the young child has age ranges and contexts in which these emotions become much more elaborate. As well as expressing begin to be expressed, developmental models of a wider range of ‘basic’ emotions such as anger, emotion concern the processes through which the fear, sadness, or joy, the young child has now emotional life of the infant might unfold. At developed the capacity for more complex emotions, the heart of such models lies a question that 1 such as embarrassment, pride, shame, and guilt. was framed by Mascolo and Griffin as ‘What These simple observations raise many important and develops in emotional development?’ One starting point for addressing this question is to categorize ∗Correspondence to: [email protected] theories of emotion according to their theoretical Department of Psychology, Temple University Philadelphia, PA, assumptions, and then to examine how developmental United States considerations relate to these assumptions. There are DOI: 10.1002/wcs.51 four main contemporary metatheoretical paradigms Volume 1, May/June 2010 2010 John Wiley & Sons, Ltd. 417 Advanced Review wires.wiley.com/cogsci under which the construct of emotion has been DET has also faced questions from developmentalists. studied: structuralist, functionalist, sociocultural, and For instance, rather than showing differentiated facial dynamical systems approaches.2,3 Although the latter expressions of anger, it has been suggested that two have seen the most applications to developmental young infants tend to produce more undifferentiated theory, all four are briefly considered here. expressions of distress.9 Structuralist approaches focus on the form of Returning to the question of what develops emotions, and as such are mainly concerned with in emotional development, it could be said that in emotions as discrete combinations of overt behav- proposing a relative invariance in the form of emo- ior (e.g., facial expressions), physiological states, and tions across the lifespan, DET is not a particularly emotional experience. This theme is reflected in the developmental theory. A more nuanced, structural- structuralist emphasis on classifying single, discrete ist approach comes from differentiation theories of emotions as particular combinations of objective emotional development, which have their origins in (overt behavioral and physiological) and subjective the work of Bridges.10 Broadly construed, differenti- responses. The subjective component of emotion is ation theories see discrete emotions as emerging from usually seen as first-person experience of emotion, as simpler precursors, such as distress or pleasure. The accessed by having individuals report on which the primary contemporary example of such a proposal emotion they are experiencing. From a structuralist comes from Sroufe.11 While his account could still perspective, the subjective component of an emo- be considered to have structuralist overtones, it is tion is a product of perceiving the bodily movements more developmentally sophisticated, is more oriented and physiological changes that comprise the objective toward a systems approach, and differs from DET in a component of the emotion. The objective aspects of number of important respects. For instance, compared an emotion (i.e., the expression) are therefore posited with DET, Sroufe proposes a much looser develop- to be tightly linked to the subjective (i.e., experiential) mental correspondence among facial expressions, the components. situational factors that elicit emotion, and the other In terms of structuralist approaches that have behavioral and experiential components of emotion. included developmental considerations, the primary Although related accounts such as that of model is Izard’s Differential Emotions Theory (DET; Sroufe11 do not emphasize a tight linkage between see Refs [4,5]). In this model, discrete emotion emotion components in early development, in many states reflect innately specified combinations of ways the coherence of the classical structuralist objective (i.e., expressive and neurophysiological) account of emotion depends on a convergence between and subjective (i.e., experiential) components. From the subjective and objective components of emotion. this perspective, the expression of discrete emotions However, it is widely agreed that this dependence has occurs in early infancy, following a period of not received wide-empirical support, a problem which neurological maturation in the first weeks of life. promoted the emergence of functionalist approaches As is commonly seen in structuralist approaches, DET that diminish the importance of the form of an puts an emphasis on facial expressions of emotion as emotion and instead place particular explanatory direct manifestations of the activity of the emotion value on the function that the emotion fulfills for the system, and it posits a one-to-one correspondence individual in their particular context.12 Evaluation of between particular expressions and discrete emotion the function of an emotion involves a consideration states across the lifespan.6 The major developmental of how the emotion fits within the activity of assumptions of DET also include the notion that the individual, and how it relates to his or her the infant facial expressions share close similarities goals or motives. Such an examination of function with corresponding expressions in adults, and that necessarily entails examining the broader contexts specific expressions are reliably elicited by infants in in which emotions are expressed or experienced, appropriate contexts.7 For the application of DET and as such it calls for a more systems-oriented to emotional development, Izard developed particular view. While functionalist approaches do allow for coding systems for identifying facial expressions of the possibility that particular emotions may be emotion in infants.8 more likely to be linked to particular patterns of As noted by Camras and Fatani,2 the original responding than others, these links are posited to vary formulation of DET has been challenged on a according to the specific context—with the response number of fronts, including a questioning of its being primarily tailored to meet the individual’s key assumptions such as the universality of facial goal.13 In functionalist approaches, a comparison or expressions of emotion and the correspondence appraisal of the individual’s situation with their goals between objective and subjective aspects of emotion. results in a readiness to act and adjust the relation 418 2010 John Wiley & Sons, Ltd. Volume 1, May/June 2010 WIREs Cognitive Science The development of emotion between the individual and