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Emotion has three aspects: physiological arousal, expressive display, and the subjective experiences of feelings and desires, or affects. These three aspects do not always vary together. One can have emotion-related physiological responses without display or experience, and display without physiological responses. In fact, people who are very expressive often tend to have smaller physiological responses than persons who are not, leading to distinctions between "externalizing" and "internalizing" modes of expression. And, neither physiological response nor expressive display is necessarily very closely tied with reported subjective experience.
This lack of correlation between indicators of emotion has often been seen as problematic for the unitary reality of the concept of emotion. It is often assumed that if a scientific concept is to be meaningful, different measures related to that concept should vary together, and in the case of emotion it is clear that they do not. However, we can explain this by considering how these three aspects of emotion are experienced in daily life by children and their caregivers.
Imagine that a little boy, Johnny, is playing with blocks. As his carefully constructed tower of blocks falls, he screams and throws a block. At this point, we can assume that all three aspects of emotion vary together. First, Johnny has physiological responses associated with the classic fight-or-flight reaction, with arousal of the sympathetic branch of the autonomic nervous system causing heart rate and blood pressure increases, increases in the activation of certain sweat glands, and hormonal releases associated with stress, including cortisol. He also vocalizes with a loud and piercing scream, and shows a facial display including the eyebrows drawn down and together at the midline, tensed upper and lower eyelids, and a squared mouth showing the teeth. He throws the block with force, perhaps hitting something in the process. And, Johnny feels something unique: strong and negative but different from some other strong and negative feelings.
At this time an adult present, perhaps Johnny's mother, may say to him: "Johnny, don't throw your blocks! You've been playing with those too long: you are frustrated and angry, but you shouldn't throw things. Go to your room and relax, and come back when you're feeling better." In those few words, Johnny's mother had given him a great deal of information about his feelings and desires, what they are called in English (frustration and anger), what he should do when they occur (relax), and what he should NOT do (throw things). This educates Johnny about these feelings (emotional education) and instructs him about what he should and should not do when they occur (emotional competence). In the future, he may be better able to recognize those feelings before they get too strong, and change his behavior accordingly.
However, imagine that Johnny is Janie, and that when she does exactly the same thing as Johnny, the adult says "You are a bad girl! Go to your room!" This gives the child no information about the feelings and desires the child is feeling, and no information about what actions might be appropriate. Instead, the child is, in effect, rejected for the display of anger. In the future, Janie might respond to similar feelings not by expressing them, but rather by suppressing any display for fear of punishment. Physiological responses would tend to be increased, both by the lack of behavioral release and also because being punished is stressful in its own right. And, the child will not be given the labels for the feelings she is experiencing: the feelings will be associated with being considered a bad girl and being painfully rejected. Janie and Johnny of course might experience very different patterns of emotional instruction in other situations: young boys learn early on not to cry or be afraid, while those reactions are generally better tolerated for girls in U.S. culture.
The learning associated with physiological responding, expressive display, and subjective experience are different because of the differences in the visibility or accessibility of these responses to the child and adult socialization agent in the process of social learning. Subjective experiences are accessible only to the child, the expressive display is particularly accessible to the adult, and physiological responses are not very accessible to either. The adult cannot know the child's feelings directly or the physiological responses, but responds to the display: the same action that suppresses the display can increase the physiological response and undermine the child's understanding of feelings, contributing perhaps to alexithymia (no words for mood). The child is aware of her feelings but, unlike awareness of an object that is equally accessible to child and adult (such as a blue chair) labeling of one's feelings is indirect, from others' responses to the child's expressive displays. Such learning can easily go awry. As a result, different indices of emotion must be expected to relate to one another in complex ways.
