Wednesday, March 11, 2009


Austin E. Grigg
of Richmond

An emotion can be described as a person's acute or relatively short-lived reaction that is revealed in his or her behavior as well as felt in his or her conscious experience. An emotion is generally accompanied by widespread changes in physiological functioning—increased pulse and breathing rates, for example. An emotion is usually initiated as a reaction to factors outside the individual—circumstances in his environment.

With many emotions, there appear to be two particular behavioral reactions. First, there occur well-integrated reflex patterns like those observed in smiling, crying, rage, or the startle reflex. Second, there are motivational manifestations—persistent purposive actions, such as efforts to escape an unpleasant or frightening situation, or deliberate violent behavior in response to anger. The motivational function of emotions is generally accepted by psychologists, but there is less agreement that each emotion must necessarily involve integrated reflex patterns.

Problems in Defining Emotion

From antiquity, writers have described emotions and their effects on behavior. The word "emotion" comes from the Latin emovere, which means to stir up, agitate, or excite. The language of every literate culture includes hundreds of words that describe feelings or emotions. It is easy to identify intense reactions of fear, anger, grief, or joy as emotions. There is general agreement that joy differs from sorrow and that disgust is unlike pleasure.

Nevertheless, students of behavior have faced problems in attempting to formulate a precise definition of emotion. It would seem that the person who experiences some emotion could be used as the source for an accurate description and definition of the state. However, two people experiencing joy, for example, may provide strikingly different descriptions of feeling joyful. Also, an outside observer might protest that joy was not really aroused, and that the individual was not really very happy. Thus individuals who claim to experience the same emotion may describe dissimilar feelings, and an outside observer may insist that neither is describing what the observer has in mind for the particular emotional feeling.

Late in the 19th century, scientists believed that they could solve the dilemma by studying the physiological reactions that occur during emotional experiences. Subsequent research, however, indicated that even this approach does not provide a precise definition. It has been found that different emotions show highly similar physiological reactions. In many instances the physiologist can tell that an emotional reaction is occurring but cannot determine exactly which emotion the individual is experiencing.

Another theory of emotion was proposed in the 19th century by Charles Darwin. His investigation of evolution led him to believe that humanity's behavior contains residuals of responses that had been necessary in lower forms of animals and in earlier times for humans but are no longer as essential for survival. In 1872 he compared certain emotional expressions in man to the role of such reactions in animals. He pointed out that baring the teeth was typical in animals when preparing to fight, and he saw a relationship between this and humans' tendency to bare their teeth when extremely angry. Darwin concluded that there is something very primitive about emotion. His theory has not been generally useful to psychologists.

The James-Lange Theory

The most influential theory of emotions was proposed in 1884 by William James, who was an American psychologist and philosopher. A Danish physiologist, Carl Lange, without prior knowledge of James's writings, published the same concept in 1887. The proposition came to be known as the James-Lange theory. Prior to the formulation of this theory, it had been assumed that emotions were aroused by ideas that the provoking situation aroused in the individual's mind. To use a simple example: person sees bear; person feels afraid; person runs away. James and Lange reversed the sequence: person sees bear; person runs away; person feels afraid. According to this view, the physiological reactions are an immediate reflex response to the provoking stimulus. The emotion appears only when the individual senses that bodily changes are occurring. Emotion, according to this theory, is the awareness of physiological reactions—for example, in the glands and other organs in the abdomen—that are aroused at once when the provoking situation affects the observer. Accordingly, individuals do not cry because they feel sad; they are sad because they have begun to cry. Whereas it had been assumed that physiological reactions followed some sort of judgment or appreciation of the provoking situation as safe or dangerous, good or bad, pleasant or unpleasant, the James-Lange theory asserted that the physiological reactions either preceded or were at the very least simultaneous with the awareness of an emotional experience.

The Cannon-Bard Theory

Another theory of emotions, known as the Cannon-Bard theory, was first recognized by the American physiologist Walter B. Cannon in 1927 and was elaborated by another American physiologist, Philip Bard, in 1934. This theory stresses the role in emotions of the hypothalamus and other structures in the brain. Cannon's experiments with animals showed that removal of the hypothalamus eliminated the familiar patterns of emotional response. Experiments with animals also demonstrated that emotional behavior is not changed radically when the nerve links between the brain and various organs are severed, a finding that contradicts the James-Lange theory. Moreover, it was found that rather sharp differences in organic changes from emotion to emotion, as predicted by the James-Lange theory, do not seem to occur. Cannon also found that it is possible by means of drugs to produce striking organic changes but that the changes do not seem to produce emotions. Cannon felt that the abdominal organs are rather insensitive and that messages from there are so diffuse that it would be difficult to explain how specific feelings could result from such indistinct signals. The Cannon-Bard theory holds that both emotional experience and physiological changes are set off simultaneously through activation of the hypothalamus.

The Perceptual-Motivational Theory

Two American psychologists, Magda Arnold in 1960 and R. W. Leeper in 1965, arrived at a similar view of emotion, known as the perceptual-motivational theory. In her theory, Arnold stressed the judgment that the individual makes of the provoking situation. She asserted that the individual appraises the provoking situation immediately as potentially pleasant or unpleasant and that the emotion follows promptly from this judgment. This theory holds that emotion is a form of motivation, a drive to experience circumstances that are judged to be pleasant and to avoid situations that are judged to be unpleasant. Whereas the James-Lange theory holds that the body reacts reflexedly on encountering the provoking situation, the Arnold view is that the body responds to the individual's appraisal of the provoking situation.

No fully satisfactory explanation or theory of emotion has been formulated. From the psychological view, it has been difficult to establish theories of emotional responsiveness because different people may react in widely different ways to the supposedly same emotion. From the physiological view, a persistent problem has been that most of the bodily mechanisms that have been described as occurring in emotion have been known also to occur in the absence of emotion.

Action of the Nervous System

During intense emotion, the whole organism appears to be involved, but many of the most significant reactions may be traced to the autonomic nervous system. The autonomic system contains nerve groups that are located outside the brain and function with some independence of the brain and central nervous system. This somewhat self-regulated (autonomous) system is divided intotwo parts. The sympathetic system is most active during emotional states. The craniosacral division, known as the parasympathetic system, controls functions that go on during quiet states—digestion, for example. Typically, the sympathetic system works in opposition to the parasympathetic. Thus if one system accelerates the activity of some body organ, the other system inhibits the functioning of the organ.

In emotions the sympathetic system accelerates the heartbeat, whereas the parasympathetic checks the rate of heartbeat. Secretions of the adrenal gland are accelerated by the sympathetic system. Many physiological changes observed during certain emotions are responses to the sympathetic division of the autonomic nervous system: speeding of the heartbeat, increase in rate of respiration, increased perspiration, increased supply of epinephrine (adrenalin) in the bloodstream, concentration of the blood supply in the skeletal muscles, and increase in the amount of blood sugar released from the liver.

Emotions and Behavior

When an individual remains under prolonged emotional tension, physiological changes may accumulate. This condition may produce disturbances in behavior, mostly because the prolonged activation of the autonomic nervous system brings about deviations from normal physiological functioning. In 1938 the American psychiatrist Flanders Dunbar presented a strong case for the role of emotion in producing physical illness, reporting evidence that the response of the physiology of the body to prolonged emotional tension may produce psychosomatic symptoms. Such symptoms are not initiated by microbes or by other traditional causes of physical diseases but are seen as the consequences of emotional tensions. Hence, they are called psychosomatic illnesses, or illnesses of psychogenic origin.

This concept of the causal role of emotions in producing physical symptoms began to receive prominence late in the 19th century when the French neuropsychiatrist Jean Charcot reported his studies of the emotional factors in hysteria. Sigmund Freud also described the emotional basis of physical symptoms in hysteria and in other forms of neurosis. In the United States, Adolf Meyer, the Johns Hopkins neuropsychiatrist, developed during the first three decades of the 20th century what he called the theory of psychobiological parallelism. He stressed the role of emotional factors in both physical and mental health. Cannon reported his famous experiments on the physiological effects of acute emotion in 1938. During World War II, military psychiatrists reported numerous instances of profound changes in bodily function as well as in mental stability that appear to have been precipitated by intense and prolonged emotional states.

Attempts to Classify Emotions

Many schemes have been proposed for classifying emotions, but these are of little more than academic interest. Most authorities divide emotions into those that are pleasant (such as joy and love) and those that are unpleasant (fear and grief). An American psychologist, M. A. Wenger, held that most subjective descriptions of emotions can be classified along certain dimensions, or axes: undifferentiated excitement, axis of fear (for example, terror, anxiety, apprehension), axis of pain, of anger, of disappointment, of sexual excitement, and of relief.

Another American psychologist, Robert Plutchik, developed a scale of intensity of emotion based on the judgments of a large number of students who were asked to rate how strongly they had experienced various feelings. In a table of emotions based on judgments about intensity, he listed ecstasy, rage, and terror as the most intense, and annoyance and dislike as moderate in intensity.

Development of Emotional Expression

A great deal of attention has been given to the development of emotional expression in infants and throughout childhood. There is general agreement that shortly after birth the only distinguishable emotion is a kind of generalized agitation or excitement. Kathrine M. B. Bridges has shown that as the infant becomes older, an increasing number of emotions become apparent. She found, for example, that a 3-month-old infant can express delight and distress; a 6-month-old baby can express anger, disgust, and fear; and a 1-year-old can express elation and affection.

Despite variations in home background and experiences, the capacity for specific emotional reactions appears at about the same age in all children. This suggests that the capacity to display emotions develops by a process of biological maturation and that there is a reliable, biologically determined sequence of development of emotional responsiveness. A 6-month-old infant cannot express jealousy, for example, but toddlers of 15 months are often reported to display such feelings. Although the capacity to express emotions occurs through maturation, the objects or circumstances that are capable of arousing the particular emotion in a specific individual depend upon the learning experiences of the child.

Encyclopedia Americana, 2009

Also See Morality and Emotions in this blog.

Further Reading

Buck, Ross, The Communication of Emotion (Guilford Press 1984).

Evans, Phil, Motivation and Emotion (Routledge 1989).

Gainotti, G., and C. Caltagirone, eds., Emotions and the Dual Brain (Springer-Verlag 1989).

Harris, P., Children and Emotions: The Development of Psychological Understanding (Basil Blackwell 1989).

Lyons, W., Emotion (Cambridge 1980).

Rorty, Amelie O., ed., Explaining Emotions (Univ. of Calif. Press 1980).