EMOTION

any of a number of extremely complex phenomena that are a synthesis of subjective experience, expressive behaviour, and neurochemical activity. Though psychologists have not found a simple yet comprehensive definition of emotion, they have generally agreed that emotions entail, to varying degrees, awareness of one's environment or situation, bodily reactions, and approach or withdrawal behaviour. Contemporary thinking on emotion is grounded in psychological experimentation, but the use of the experimental method in psychology came only after about 1850. The pioneer in this area was the German psychologist Wilhelm Wundt, who performed experiments in which subjects provided introspective reports of their responses to stimuli that were varied in a controlled way. Contemporary with Wundt's work was a theory, offered by English naturalist Charles Darwin, that helped to focus investigation into emotion. In this theory Darwin suggested that emotional behaviour in animals was a vestige of adaptive behaviour from an earlier stage of the given species' development. A particularly influential early theory of emotion was proposed independently by the American psychologist William James and the Danish physician Carl Georg Lange. The James-Lange theory firmly links mental states to physiological processes: it holds that an emotion is a perception of phenomena within the body. When a person sees a frightening sight, for example, the body immediately responds in certain ways (e.g., the heart rate increases). The perception of bodily response to the original stimulus constitutes the emotion of fear, according to the James-Lange view. Thus people are happy because they smile, sad because they cry, and afraid because they flee. It has been shown that emotions are accompanied by physiological changes manifested by excitation of the sympathetic division of the autonomic nervous system; specifically, these changes can be detected in the galvanic skin response (see psychogalvanic reflex), in which the electrical conductivity of the skin varies, and also in the heart rate, blood pressure, perspiration, and others. But according to the James-Lange view, these physiological changes would themselves be stimulated by a perception. It is argued that, by the time a signal from the senses reaches the appropriate centre in the brain, physiological changes have already taken place to cause the signal which then produces the feeling of the emotion. This element of the James-Lange view raised some serious objections. An American physiologist, Walter B. Cannon, proposed a theory that became one of the chief arguments against the James-Lange view. Cannon showed that subjects reacted emotionally even when nerves connecting the central nervous system to various organs were severed, suggesting that physiological changes were not necessarily the primary cause of emotion. Cannon also proposed that signals from the senses may be received by the thalamus, which performs the dual function of providing the emotional content to the appropriate perceptual centre and transmitting the stimulus to other parts of the body. Further research has called into question Cannon's view of the preeminence of the thalamus for emotions. But the basic insight of his theory continues to be upheld, with more sophisticated anatomical support. Cannon's successors examined a structure called the reticular formation, in the centre of the brain stem. Electrical activity throughout the brain was found to be accompanied by electrical activity in the reticular formation. Emotion is held to be the result of a certain level of reticular-formation activation, a level less than that necessary to sustain such brain functions as perception and behaviour. Because the reticular formation serves to integrate virtually all brain activity, any perception or action is necessarily infused with emotional content. A perceptual-motivational theory of emotion was individually proposed by American psychologists Magda Arnold, in 1960, and R.W. Leeper, in 1965. According to the theory, emotions are no more than strong motivational or drive states (see motivation). A motivational state is an inner condition of imbalance (for example, thirst) that provokes an organism to take some remedial action (in this case, to search for a drink). Although this approach to emotion was shown to be incomplete, later research gave evidence of what appear to be anatomical mechanisms of motivation. Significantly, these mechanisms serve a function in emotional behaviour as well. The mechanisms in question involve the hypothalamus, a small structure near the base of the brain. The hypothalamus plays a very complex role in regulating a variety of physiological processes. It is also involved in behaviour that expresses the emotions of anger and fear. The results of complicated experiments involving electrical stimulation of the hypothalamus and related brain structures have led researchers to propose that emotions result from a dynamic process of stimulation and inhibition of certain bodily movements, as regulated by the hypothalamus. An objection to this view is that it ignores the cognitive element in emotions. Presumably the same physiological events might be said to underlie emotions directed at different objects; how then are the emotions to be distinguished? It is here that the importance of perception and learning to discussions of emotion is apparent. However, the cognitive element in emotion cannot be processed by the relatively simple brain structures considered so far. While these can lead to emotional expression, the cognitive element must be processed by more complex structures found in higher parts of the brain. Modern researchers often view emotions in three components, physiological, expressive, and experiential, each of which can be studied in terms of structure and functions. a distinct feeling or quality of consciousness, such as joy or sadness, that reflects the personal significance of an emotion-arousing event. In modern times the subject of emotion has become part of the subject matter of several scientific disciplinesbiology, psychology, psychiatry, anthropology, and sociology. Emotions are central to the issues of human survival and adaptation. They motivate the development of moral behaviour, which lies at the very root of civilization. Emotions influence empathic and altruistic behaviour, and they play a role in the creative processes of the mind. They affect the basic processes of perception and influence the way humans conceive and interpret the world around them. Evidence suggests that emotions shape many other aspects of human life and human affairs. Clinical psychologists and psychiatrists often describe problems of adjustment and types of psychopathology as emotional problems, mental conditions that an estimated one in three Americans, for example, suffers from during his or her lifetime. The subject of emotion is studied from a wide range of views. Behaviorally oriented neuroscientists study the neurophysiology and neuroanatomy of emotions and the relations between neural processes and the expression and experience of emotion. Social psychologists and cultural anthropologists study similarities and differences among cultures by the way emotions are expressed and conceptualized. Philosophers are interested in the role of emotions in rationality, thought, character development, and values. Novelists, playwrights, and poets are interested in emotions as the motivations and defining features of fictional characters and as vehicles for communicating the meaning and significance of events. This article considers the meaning of emotions; the use of emotion concepts in literature and philosophy; the activation, structure, and functions of emotions as conceived by psychologists and neuroscientists; and the causes and consequences of emotions as reflected in individual experience and social relationships. Additional reading Studies of philosophical and cultural views on emotion include James Hillman, Emotion: A Comprehensive Phenomenology of Theories and Their Meanings for Therapy (1960), a contemporary philosopher's explanation of emotions in terms of Aristotle's system of causes and a review of other approaches; Amlie Oksenberg Rorty (ed.), Explaining Emotions (1980), a collection of philosophical essays on the causes, meaning, and consequences of emotions; and Rom Harr (ed.), The Social Construction of Emotions (1986), a collection of studies on the role of language and culture in the cognitive construction, i.e., learning, of emotions.The significance of emotions is the subject of many analyses, beginning with Charles Darwin, The Expression of the Emotions in Man and Animals (1872, reprinted 1979), a classical work that placed human emotions in evolutionary perspective and presented the first evidence for their innateness and universality in human beings; Carroll E. Izard, Human Emotions (1977), a discussion of each of the fundamental emotions of human experience in terms of their unique organizing and motivational influence on cognition and action; Susanne K. Langer, Mind: An Essay on Human Feeling, 3 vol. (196772), a philosopher's view of the significance of feelings in the evolution of human mentality; George Mandler, Mind and Body: Psychology of Emotion and Stress (1984), a cognitive, or constructivist, view of the role of emotions in mental and bodily processes; Robert Plutchik, Emotion, a Psychoevolutionary Synthesis (1980), a look at emotions in evolutionary perspective; and Silvan S. Tomkins, Affect, Imagery, Consciousness, vol. 1, The Positive Affects (1962), a brilliant essay on emotions as the primary motivational system of human beings.The following works reflect some contemporary approaches to the study of emotions: Magda B. Arnold, Emotion and Personality, vol. 1, Psychological Aspects (1960), emphasizes the role of cognitive appraisal in emotion and sets the stage for later cognitive-social, or constructivist, theories of emotion; Nico H. Frijda, The Emotions (1986), is a comprehensive cognitive-social view of emotions; Joseph J. Campos et al., Socioemotional Development, chapter 10 in Marshall M. Haith and Joseph J. Campos (eds.), Infancy and Developmental Psychobiology, 4th ed. (1983), pp. 783915, provides a comprehensive review of theory and research on emotional development; Robert N. Emde, Theodore J. Gaensbauer, and Robert J. Harmon, Emotional Expression in Infancy: A Biobehavioral Study (1976), is an influential contribution to the study of expressions; Nathan A. Fox and Richard J. Davidson (eds.), The Psychobiology of Affective Development (1984), presents a collection of reviews of theory and research papers on the biological aspects of emotional development; Carroll E. Izard, Jerome Kagan, and Robert B. Zajonc (eds.), Emotions, Cognition, and Behavior (1984), is a collection of research papers by leading psychologists on the relations between emotions, cognition, and actions; Carroll E. Izard and C.Z. Malatesta, Perspectives on Emotional Development I: Differential Emotions Theory of Early Emotional Development, chapter 9A in Joy Doniger Osofsky (ed.), Handbook of Infant Development, 2nd ed. (1987), pp. 494554, provides a detailed theory of emotional development and a review of related research; Joseph E. Ledoux, Emotion, chapter 10 in Fred Plum (ed.), Higher Functions of the Brain (1987), pp. 41959, in Handbook of Physiology, section 1, vol. 5, discusses brain mechanisms and neural pathways involved in the activation, expression, and experience of emotion; Michael Lewis and Linda Michalson, Children's Emotions and Moods: Developmental Theory and Measurement (1983), explores a cognitive-social view of the development of emotions; Phoebe C. Ellsworth and Craig A. Smith, From Appraisal to Emotion: Differences Among Unpleasant Feelings, Motivation and Emotion, 12(3):271302 (September 1988), surveys research on the relations between appraisal processes and emotions and presents a new theory of cognitionemotion relations; H. Hill Goldsmith et al., What Is Temperament? Four Approaches, Child Development, 58(2):50529 (April 1987), reviews theories of temperament with attention to temperamentemotion relations; Alice M. Isen, Kimberly A. Daubman, and Gary P. Nowicki, Positive Affect Facilitates Creative Problem Solving, Journal of Personality and Social Psychology, 52(6):112231 (June 1987), exemplifies research showing how positive emotion facilitates creative thinking, empathy, and altruism; Carroll E. Izard, Elizabeth A. Hembree, and Robin R. Huebner, Infants' Emotion Expressions to Acute Pain: Developmental Change and Stability of Individual Differences, Developmental Psychology, 23(1):10513 (January 1987), studies change and continuity in children's emotion expressions; William James, What Is an Emotion? Mind, 9:188205 (1884), provides a classic definition of emotion that remains influential today; Jerome Kagan, J. Steven Reznick, and Nancy Snidman, Biological Bases of Childhood Shyness, Science, 240:16771 (April 1988), summarizes a series of studies on biological bases and the continuity of shyness; and Roger Sperry, Some Effects of Disconnecting the Cerebral Hemispheres, Science, 217:1223-26 (September 1982), discusses the effects of disconnecting cerebral hemispheres on mental and emotional experience. Carroll E. Izard