THE INTERRELATIONS OF EMOTIONS
Emotions gain expression through discharges along the neurones of the autonomic nervous system. The reader will recall that this system has three divisions—the cranial and sacral, separated by the sympathetic—and that when the neurones of the mid-division meet in any organ the neurones of either of the end divisions, the influence of the two sets is antagonistic. As previously stated (p. 35), there is evidence that arrangements exist in the central nervous system for reciprocal innervation of these antagonistic divisions, just as there is reciprocal innervation of antagonistic skeletal muscles. The characteristic affective states manifested in the working of these three divisions have been described. Undoubtedly, these states have correspondents—activities and inhibitions—in the central neurones. The question now arises, are the states which appear in opposed divisions also in opposition?
The cranial autonomic, as already shown, is concerned with the quiet service of building up reserves and fortifying the body against times of stress. Accompanying these functions are the relatively mild pleasures of sight and taste and smell of food. The possibility of existence of these gentle delights of eating and drinking and also of their physiological consequences is instantly abolished in the presence of emotions which activate the sympathetic division. The secretion of saliva, gastric juice, pancreatic juice and bile is stopped, and the motions of the stomach and intestines cease at once, both in man and in the lower animals, whenever pain, fear, rage, or other strong excitement is present in the organism.
All these disturbances of digestion seem mere interruptions of the “normal” course of events unless the part they may play in adaptive reactions is considered. In discussing the operations of the sympathetic division, I pointed out that all the bodily changes which occur in the intense emotional states—such as fear and fury—occur as results of activity in this division, and are in the highest degree serviceable in the struggle for existence likely to be precipitated when these emotions are aroused. From this point of view these perturbations, which so readily seize and dominate the organs that in quiet times are commonly controlled by the cranial autonomic, are bodily reactions which may be of the utmost importance to life at times of critical emergency. Thus are the body’s reserves—the stored adrenin and the accumulated sugar—called forth for instant service; thus is the blood shifted to nerves and muscles that may have to bear the brunt of struggle; thus is the heart set rapidly beating to speed the circulation; and thus, also, are the activities of the digestive organs for the time abolished. Just as in war between nations the arts and industries which have brought wealth and contentment must suffer serious neglect or be wholly set aside both by the attacker and the attacked, and all the supplies and energies developed in the period of peace must be devoted to the present conflict; so, likewise, the functions which in quiet times establish and support the bodily reserves are, in times of stress, instantly checked or completely stopped, and these reserves lavishly drawn upon to increase power in the attack and in the defense or flight.[*]
* One who permits fears, worries and anxieties to disturb the digestive processes when there is nothing to be done, is evidently allowing the body to go onto what we may regard as a “war footing,” when there is no “war” to be waged, no fighting or struggle to be engaged in.
It is, therefore, the natural antagonism between these two processes in the body—between saving and expenditure, between preparation and use, between anabolism and catabolism—and the correlated antagonism of central innervations, that underlie the antipathy between the emotional states which normally accompany the processes. The desire for food, the relish of eating it, all the pleasures of the table, are naught in the presence of anger or great anxiety. And of the two sorts of emotional states, those which manifest themselves in the dominant division of the autonomic hold the field also in consciousness.
The nervi erigentes are the part of the sacral autonomic in which the peculiar excitements of sex are expressed. As previously stated, these nerves are opposed by branches from the sympathetic division—the division which is operated characteristically in the major emotions.
The opposition in normal individuals between the emotional states which appear in these two antagonistic divisions is most striking. Even in animals as low in the scale as birds, copulation is not performed “until every condition of circumstance and sentiment is fulfilled, until time, place and partner all are fit.”[1] And among men the effect of fear or momentary anxiety or any intense emotional interest in causing inhibition of the act can be supported by cases in the experience of any physician with extensive practice. Indeed, as Prince[2] has stated, “the suppression of the sexual instinct by conflict is one of the most notorious experiences of this kind in everyday life. This instinct cannot be excited during an attack of fear or anger, and even during moments of its excitation, if there is an invasion of another strong emotion the sexual instinct at once is repressed. Under these conditions, as with other instincts, even habitual excitants can no longer initiate the instinctive process.”
When the acme of excitement is approaching it is probable that the sympathetic division is also called into activity; indeed, the completion of the process—the contractions of the seminal vesicles and the prostate, and the subsidence of engorged tissues, all innervated by sympathetic filaments (see pp. 32, 33)—may be due to the overwhelming of sacral by sympathetic nervous discharges. As soon as this stage is reached the original feeling likewise has been dissipated.
The other parts of the sacral division which supply the bladder and rectum are so nearly free from any emotional tone in their normal reflex functioning that it is unnecessary to consider them further with reference to emotional antagonisms. Mild affective states, such as worry and anxiety, can, to be sure, check the activity of the colon and thus cause constipation.[3] But the augmented activity of these parts (contraction of the bladder and rectum) in very intense periods of emotional stress, when the sympathetic division is strongly innervated, presents a problem of some difficulty. Possibly in such conditions the orderliness of the central arrangements is upset, just as it is after tetanus toxin or strychnine poisoning, and opposed innervations no longer discharge reciprocally, but simultaneously, and then the stronger member of the pair prevails. Only on such a basis, at present, can I offer any explanation for the activity and the supremacy of the sacral innervation of the bladder and distal colon when the sympathetic innervation is aroused, as, for example, in great fright.
A summary in few words of the chief functions typically performed or supported by each division of the autonomic would designate the cranial division as the upbuilder and restorer of the organic reserves, the sacral as the servant of racial continuity, and the sympathetic as the preserver of the individual. Self-preservation is primary and essential; on that depends racial continuity, and for that all the resources of the organism are called forth. Analogously the sympathetic innervations, when they meet in organs innervated also by the cranial and sacral divisions, almost without exception predominate over their opponents. And analogously, also, the emotional states which are manifested in the sympathetic division and are characteristically much more intense than those manifested in the other divisions, readily assume ascendancy also in consciousness.
It is obvious that extended action of the sympathetic division, abolishing those influences of the cranial division which are favorable to proper digestion and nutrition, might defeat its own ends. Interruption of the nutritional process for the sake of self-preservation through defense or attack can be only temporary; if the interruption were prolonged, there might be serious danger to the vigor of the organism from failure to replenish the exhausted stores. The body does not have to depend on the return of a banished appetite, however, before its need for restoration is attended to. There is a secondary and very insistent manner in which the requirement of food is expressed, and that is through the repeated demands of hunger.
Unlike many other rhythmically repeated sensations, hunger is not one that anybody becomes accustomed to and neglects because of its monotony. During the period of his confinement in the citadel of Magdeburg, the celebrated political adventurer Baron von Trenck[4] was allowed only a pound and a half of ammunition bread and a jug of water as his daily ration. “It is impossible for me to describe to my reader,” he wrote in his memoirs, “the excess of tortures that during eleven months I endured from ravenous hunger. I could easily have devoured six pounds of bread every day; and every twenty-four hours, after having received and swallowed my small portion, I continued as hungry as before I began, yet I was obliged to wait another twenty-four hours for a new morsel.... My tortures prevented sleep, and looking into futurity, the cruelty of my fate seemed to me, if possible, to increase, for I imagined that the prolongation of pangs like these was insupportable. God preserve every honest man from sufferings like mine! They were not to be endured by the most obdurate villain. Many have fasted three days, many have suffered want for a week or more, but certainly no one besides myself ever endured it in the same excess for eleven months; some have supposed that to eat little might become habitual, but I have experienced the contrary. My hunger increased every day, and of all the trials of fortitude my whole life has afforded, this eleven months was the most bitter.”[*]
* In all probability the continued experience of hunger pangs reported by Baron von Trenck was due to the repeated eating of amounts of food too small to satisfy the bodily demand. The reader will recall that persons who for some time take no food whatever report that the disagreeable feelings are less intense or disappear after the third or fourth day (see p. 238).
Thus, although the taking of food may be set in abeyance at times of great excitement, and the bodily reserves fully mobilized, that phase of the organism’s self-protecting adjustment is limited, and then hunger asserts itself as an agency imperiously demanding restoration of the depleted stores.
The dominant emotions which we have been considering as characteristically expressed in the sympathetic division of the autonomic system are fear and rage. These two emotions are not unlike. As James[5] has indicated, “Fear is a reaction aroused by the same objects that arouse ferocity.... We both fear and wish to kill anything that may kill us; and the question which of the two impulses we shall follow is usually decided by some one of those collateral circumstances of the particular case, to be moved by which is the mark of superior mental natures.” The cornering of an animal when in the headlong flight of fear may suddenly turn the fear to fury and the flight to a fighting in which all the strength of desperation is displayed.
Furthermore, these dominant emotions are states into which many other commonly milder affective states may be suddenly transformed. As McDougall[6] has pointed out, all instinctive impulses when met with opposition or obstruction give place to, or are complicated by, the pugnacious or combative impulse directed against the source of the obstruction. A dog will bristle at any attempt to take away his food, males will fight furiously when provoked by interference with the satisfaction of the sexual impulse, a man will forget the conventions and turn hot for combat when there is imputation against his honor, and a mother all gentle with maternal devotion is stung to quick resentment and will make a fierce display of her combative resources, if anyone intentionally injures her child. In these instances of thwarted or disturbed instinctive acts the emotional accompaniments—such as the satisfaction of food and of sexual affection, the feeling of self-pride, and the tender love of a parent—are whirled suddenly into anger. And anger in one is likely to provoke anger or fear in the other who for the moment is the object of the strong feeling of antagonism. Anger is the emotion preëminently serviceable for the display of power, and fear is often its counterpart.
The visceral changes which accompany fear and rage are the result of discharges by way of sympathetic neurones. It will be recalled that these neurones are arranged for diffuse rather than for narrowly directed effects. So far as these two quite different emotions are concerned, present physiological evidence indicates that differences in visceral accompaniments[*] are not noteworthy—for example, either fear or rage stops gastric secretion (see pp. 10, 11). There is, indeed, obvious reason why the visceral changes in fear and rage should not be different, but rather, why they should be alike. As already pointed out, these emotions accompany organic preparations for action, and just because the conditions which evoke them are likely to result in flight or conflict (either one requiring perhaps the utmost struggle), the bodily needs in either response are precisely the same.
* Obvious vascular differences, as pallor or flushing of the face, are of little significance. With increase of blood pressure from vasoconstriction, pallor might result from action of the constrictors in the face, or flushing might result because constrictors elsewhere, as, for example, in the abdomen, raised the pressure so high that facial constrictors are overcome. Such, apparently, is the effect of adrenin already described (see p. 107). Or the flushing might occur from local vasodilation. That very different emotional states may have the same vascular accompaniments was noted by Darwin (The Expression of Emotions in Man and Animals, New York, 1905), who mentioned the pallor of rage (p. 74) and also of terror (p. 77).
In discussing the functioning of the sympathetic division I pointed out that it was roused to activity not only in fear and rage, but also in pain. The machinery of this division likewise is operated wholly or partially in emotions which are usually mild—such as joy and sorrow and disgust—when they become sufficiently intense. Thus, for instance, the normal course of digestion may be stopped or quite reversed in a variety of these emotional states.
Darwin[7] reports the case of a young man who on hearing that a fortune had just been left him, became pale, then exhilarated, and after various expressions of joyous feeling vomited the half-digested contents of his stomach. Müller[8] has described the case of a young woman whose lover had broken the engagement of marriage. She wept in bitter sorrow for several days, and during that time vomited whatever food she took. And Burton,[9] in his Anatomy of Melancholy, gives the following instance of the effect of disgust: “A gentlewoman of the same city saw a fat hog cut up, when the entrails were opened, and a noisome savour offended her nose, she much misliked, and would not longer abide; a physician in presence told her, as that hog, so was she, full of filthy excrements, and aggravated the matter by some other loathsome instances, insomuch this nice gentlewoman apprehended it so deeply that she fell forthwith a vomiting, was so mightily distempered in mind and body, that with all his art and persuasion, for some months after, he could not restore her to herself again, she could not forget or remove the object out of her sight.”
In these three cases, of intense joy, intense sorrow and intense disgust, the influence of the cranial division of the autonomic has been overcome, digestion has ceased, and the stagnant gastric contents by reflexes in striated muscles have been violently discharged. The extent to which under such circumstances other effects of sympathetic impulses may be manifested, has not, so far as I know, been ascertained.
From the evidence just given it appears that any high degree of excitement in the central nervous system, whether felt as anger, terror, pain, anxiety, joy, grief or deep disgust, is likely to break over the threshold of the sympathetic division and disturb the functions of all the organs which that division innervates. It may be that there is advantage in the readiness with which these widely different emotional conditions can express themselves in this one division, for, as has been shown (see p. 276), occasions may arise when these milder emotions are suddenly transmuted into the naturally intense types (as fright and fury) which normally activate this division; and if the less intense can also influence it, the physiological aspect of the transmutation is already partially accomplished.
If various strong emotions can thus be expressed in the diffused activities of a single division of the autonomic—the division which accelerates the heart, inhibits the movements of the stomach and intestines, contracts the blood vessels, erects the hairs, liberates sugar, and discharges adrenin—it would appear that the bodily conditions which have been assumed, by some psychologists, to distinguish emotions from one another must be sought for elsewhere than in the viscera. We do not “feel sorry because we cry,” as James contended, but we cry because when we are sorry or overjoyed or violently angry or full of tender affection—when any one of these diverse emotional states is present—there are nervous discharges by sympathetic channels to various viscera, including the lachrymal glands. In terror and rage and intense elation, for example, the responses in the viscera seem too uniform to offer a satisfactory means of distinguishing states which, in man at least, are very different in subjective quality. For this reason I am inclined to urge that the visceral changes merely contribute to an emotional complex more or less indefinite, but still pertinent, feelings of disturbance in organs of which we are not usually conscious.
This view that the differential features of emotions are not to be traced to the viscera is in accord with the experimental results of Sherrington,[10] who has demonstrated that emotional responses occur in dogs in which practically all the main viscera and the great bulk of skeletal muscle have been removed from subjection to and from influence upon the brain, by severance of the vagus nerves and the spinal cord. In these animals no alteration whatever was noticed in the occurrence, under appropriate circumstances, of characteristic expressions of voice and features, indicating anger, delight or fear. The argument that these expressions may have been previously established by afferent impulses from excited viscera was met by noting that a puppy only nine weeks old also continued to exhibit the signs of emotional excitement after the brain was disconnected from all the body except the head and shoulders. Evidence from uniformity of visceral response and evidence from exclusion of the viscera are harmonious, therefore, in minimizing visceral factors as the source of differences in emotional states.[*]
* The paucity of afferent fibres in the autonomic system, and the probability of an extremely low degree of sensitiveness in the viscera (for evidence, see Cannon: The Mechanical Factors of Digestion, London, 1911, p. 202), likewise support this conclusion.
If these differences are due to other than visceral changes, why is it not always possible by voluntary innervations to produce emotions? We can laugh and cry and tremble. But forced laughter does not bring happiness, nor forced sobbing sorrow, and the trembling from cold rouses neither anger nor fear. The muscle positions and tensions are there, but the experiencing of such bodily changes does not seem even approximately to rouse an emotion in us. Voluntary assumption of an attitude seems to leave out the “feeling.” It is probable, however, that no attitude which we can assume has all the elements in it which appear in the complete response to a stirring situation. But is not this because the natural response is a pattern reaction, like inborn reflexes of low order, such as sneezing, in which impulses flash through peculiarly coöperating neurone groups of the central system, suddenly, unexpectedly, and in a manner not exactly reproducible by volition, and thus they throw the skeletal muscles into peculiar attitudes and, if sufficiently intense, rush out in diffuse discharges that cause tremors and visceral perturbations? The typical facial and bodily expressions, automatically assumed in different emotions, indicate the discharge of peculiar groupings of neurones in the several affective states. That these responses occur instantly and spontaneously when the appropriate “situation,” actual or vividly imagined, is present, shows that they are ingrained in the nervous organization. At least one such pattern, that of anger, persists after removal of the cerebral hemispheres—the decorticated dog, by growling and biting when handled, has the appearance of being enraged;[11] the decerebrate cat, when vigorously stimulated, retracts its lips and tongue, stares with dilated pupils, snarls and snaps its jaws.[12] On the other hand, stroking the hair, whistling and gently calling to produce a pleased attitude, or yelling to produce fright, have not the slightest effect in evoking from the decorticated dog signs of joy and affection or of fear, nor does the animal manifest any sexual feeling. The absence of bodily indications of these emotions is quite as significant as the presence of the signs of anger. For since expressions of anger can persist without the cerebral cortex, there is little reason why the complexes of other emotional expressions, if their “machinery” exists below the cortex, should not also be elicitable. That they are not elicitable suggests that they require a more elaborately organized grouping of neurones than does anger—possibly what the cortex, or the cortex in combination with basal ganglia, would provide.
The contrast between the brevity of the “pseudo-affective reactions” in the decerebrate cat, though the viscera are still connected with the central nervous system, and the normal duration of emotional expression in the dog with the body separated from the head region, has been used by Sherrington to weigh the importance of the visceral and other factors. And the evidence which I have given above, as well as that which he has offered, favors the view that the viscera are relatively unimportant in an emotional complex, especially in contributing differential features.
1 James: Principles of Psychology, New York, 1905, i, p. 22.
2 Prince: The Unconscious, New York, 1914, p. 456.
3 Hertz: Constipation and Allied Intestinal Disorders, London, 1909, p. 81.
4 v. Trenck: Merkwürdige Lebensgeschichte, Berlin, 1787, p. 195.
5 James, Loc. cit., p. 415.
6 McDougall: Introduction to Social Psychology, London, 1908, p. 72.
7 Darwin: Loc. cit., p. 76.
8 Müller: Deutsches Archiv für klinische Medicin, 1907, lxxxix, p. 434.
9 Burton: The Anatomy of Melancholy (first published in 1621), London, 1886, p. 443.
10 Sherrington: Proceedings of the Royal Society, 1900, lxvi, p. 397.
11 Goltz: Archiv für die gesammte Physiologie, 1892, li, p. 577.
12 Woodworth and Sherrington: Journal of Physiology, 1904, xxxi, p. 234.