The autonomic is not separate from the main nervous system, but consists of outgoing axons from centers in the cord and "medulla" (part of the brain stem). It has three divisions, one from the medulla, one from the middle reach of the cord, and one from the lower part of the cord; and these three divisions are related to three different emotional states. The upper division, from the medulla, favors digestion by promoting the flow of gastric juice and the churning movements of the stomach; and at the same time it seems to favor the comfortable, rather lazy state that is appropriate for digestion. The middle division (often called the "sympathetic", though the name is rather misleading to a student of psychology, as it has nothing to do with "sympathy") checks digestion, hastens the heart beat, and stimulates the adrenal glands to rapid secretion, thus giving [{125}] rise to the organic condition of anger. The lower division has to do with the bladder, rectum and sex organs, and is active during sex excitement, for one thing.
The lower centers in the medulla and cord that give rise to the autonomic nerves are themselves much under the influence of the higher, cerebral centers. Thus appetite for food, and the flow of gastric juice, can be aroused by the sight of good food, or by hearing or reading about food, or even by merely thinking of food; and both anger and sex appetite can be aroused in corresponding ways.
We should notice right here the antagonism that exists between the middle division of the autonomic and the other two. Suppose the upper division is active, as in comfortable digestion, when an angering stimulus supervenes; then, as we have seen, digestion halts, the upper autonomic is shunted out of action by the middle division. In the same way, sex appetite is shunted out by anger.
The Emotional State as a Preparatory Reaction
An emotion is often spoken of as a disturbance of the normal quiet state, and as if it represented a breakdown of the organism's machinery. Anger or fear is often a nuisance in civilized life, and any strong emotion is apt to disturb mental work or skilled manual work. But if we think ourselves back into a primitive condition of life, when anger means a fight, we see that the organic response in anger makes a first-class preparation for the fight. Rapid circulation, abundant muscular fuel, protection from fatigue--these are all positively useful; and the halting of digestion is useful also in relieving the circulation from taking care of an activity that can afford to wait.
What we have been calling the "organic state in anger" occurs also in fear of the strong type (as distinguished from [{126}] fear paralysis), and in certain other states that are not exactly either fear or anger, such as the state of a football player before the game, or the state of a student about to take an examination. It is the state of excitement or of being "all keyed up". So far as known, the organic response (including the adrenal secretion) is the same in these various instances of excitement: anger, fear, zeal and so on. When an individual is in this organic state, his muscles will work harder and longer than is otherwise possible; and thus are explained those remarkable cases of extraordinary strength and endurance in great emergencies, as in escaping from a fire or from a bombarded city.
The fear-anger state of the organism, being certainly a state of preparedness for attack or defense, suggests the following generalization: "Any emotion represents internal preparation for some type of overt action." This holds good, at least, for food appetite and sex appetite. Regarding the other emotions, we know too little of the internal responses that may occur, to judge whether or not they have any utility as preparatory reactions.
"Expressive Movements," Another Sort of Preparatory Reactions
Though we know little of any internal response in many of the emotions, we almost always find some characteristic external movement, such as smiling, scowling, pouting, sneering, sobbing, screaming, shouting or dancing. By aid of such "expressive movements" we are sometimes able to judge the emotional state of another person. But what is the sense of these movements? At first thought, the question itself is senseless, the movements are so much a matter of course, while on second thought they certainly do seem odd. What sense is there is protruding the lips when sulky, [{127}] or in drawing up the corners of the mouth and showing the canine teeth in contempt? Perhaps they are just odd tricks of instinct--for we agreed in the preceding chapter not to assume all instinctive responses to be useful. Darwin, however, after studying a great many of these expressive movements, both in men and in animals, reached the conclusion that, if not of present utility, they were survivals of acts that had been useful earlier in the life of the individual or of the race.
Shaking the head from side to side, in negation or unwillingness, dates back to the nursing period of the individual's life, when this movement was made in rejecting undesired food. Directly useful in this case, it was carried over to analogous situations that aroused the child's reluctance.