The Expression of Emotion in Man and Animals - Charles Darwin (an ebook reader TXT) 📗

so that, when the cerebro-spinal system is highly excited and nerve-force is liberated in excess, it may be expended in intense sensations, active thought, violent movements, or increased activity of the glands.[7] Mr. Spencer further maintains that an “overflow of nerve-force, undirected by any motive, will manifestly take the most habitual routes; and, if these do not suffice, will next overflow into the less habitual ones.”

Consequently the facial and respiratory muscles, which are the most used, will be apt to be first brought into action; then those of the upper extremities, next those of the lower, and finally those of the whole body.[8]

 

[4] Mr. Bartlett, “Notes on the Birth of

a Hippopotamus,” Proc. Zoolog. Soc. 1871, p. 255.

 

[5] See, on this subject, Claude Bernard, `Tissus Vivants,’ 1866, pp.

316, 337, 358. Virchow expresses himself to almost exactly the same effect in his essay “Ueber das Ruckenmark” (Sammlung wissenschaft.

Vortrage, 1871, s. 28).

 

An emotion may be very strong, but it will have little tendency to induce movements of any kind, if it has not commonly led to voluntary action for its relief or gratification; and when movements are excited, their nature is, to a large extent, determined by those which have often and voluntarily been performed for some definite end under the same emotion. Great pain urges all animals, and has urged them during endless generations, to make the most violent and diversified efforts to escape from the cause of suffering.

Even when a limb or other separate part of the body is hurt, we often see a tendency to shake it, as if to shake off the cause, though this may obviously be impossible. Thus a habit of exerting with the utmost force all the muscles will have been established, whenever great suffering is experienced. As the muscles of the chest and vocal organs are habitually used, these will be particularly liable to be acted on, and loud, harsh screams or cries will be uttered.

But the advantage derived from outcries has here probably come into play in an important manner; for the young of most animals, when in distress or danger, call loudly to their parents for aid, as do the members of the same community for mutual aid.

 

[6] Muller (`Elements of Physiology,’ Eng. translat. vol. ii. p. 932) in speaking of the nerves, says, “any sudden change of condition of whatever kind sets the nervous principle into action.” See Virchow and Bernard on the same subject in passages in the two works referred to in my last footnote.

 

[7] H. Spencer, `Essays, Scientific, Political,’ &c., Second Series, 1863, pp. 109, 111.

 

[8] Sir H. Holland, in speaking (`Medical Notes and Reflexions,’

1839, p. 328) of that curious state of body called the fidgets, remarks that it seems due to “an accumulation of some cause of irritation which requires muscular action for its relief.”

 

Another principle, namely, the internal consciousness that the power or capacity of the nervous system is limited, will have strengthened, though in a subordinate degree, the tendency to violent action under extreme suffering.

A man cannot think deeply and exert his utmost muscular force.

As Hippocrates long ago observed, if two pains are felt at the same time, the severer one dulls the other.

Martyrs, in the ecstasy of their religious fervour have often, as it would appear, been insensible to the most horrid tortures.

Sailors who are going to be flogged sometimes take a piece of lead into their mouths, in order to bite it with their utmost force, and thus to bear the pain. Parturient women prepare to exert their muscles to the utmost in order to relieve their sufferings.

 

We thus see that the undirected radiation of nerve-force from the nerve-cells which are first affected—the long-continued habit of attempting by struggling to escape from the cause of suffering—

and the consciousness that voluntary muscular exertion relieves pain, have all probably concurred in giving a tendency to the most violent, almost convulsive, movements under extreme suffering; and such movements, including those of the vocal organs, are universally recognized as highly expressive of this condition.

 

As the mere touching of a sensitive nerve reacts in a direct manner on the heart, severe pain will obviously react on it in like manner, but far more energetically. Nevertheless, even in this case, we must not overlook the indirect effects of habit on the heart, as we shall see when we consider the signs of rage.

 

When a man suffers from an agony of pain, the perspiration often trickles down his face; and I have been assured by a veterinary surgeon that he has frequently seen drops falling from the belly and running down the inside of the thighs of horses, and from the bodies of cattle, when thus suffering.

He has observed this, when there has been no struggling which would account for the perspiration. The whole body of the female hippopotamus, before alluded to, was covered with red-coloured perspiration whilst giving birth to her young.

So it is with extreme fear; the same veterinary has often seen horses sweating from this cause; as has Mr. Bartlett with the rhinoceros; and with man it is a well-known symptom.

The cause of perspiration bursting forth in these cases is quite obscure; but it is thought by some physiologists to be connected with the failing power of the capillary circulation; and we know that the vasomotor system, which regulates the capillary circulation, is much influenced by the mind.

With respect to the movements of certain muscles of the face under great suffering, as well as from other emotions, these will be best considered when we treat of the special expressions of man and of the lower animals.

 

We will now turn to the characteristic symptoms of Rage. Under this powerful emotion the action of the heart is much accelerated,[9]

or it may be much disturbed. The face reddens, or it becomes purple from the impeded return of the blood, or may turn deadly pale.

The respiration is laboured, the chest heaves, and the dilated nostrils quiver. The whole body often trembles. The voice is affected.

The teeth are clenched or ground together, and the muscular system is commonly stimulated to violent, almost frantic action.

But the gestures of a man in this state usually differ from the purposeless writhings and struggles of one suffering from an agony of pain; for they represent more or less plainly the act of striking or fighting with an enemy.

 

All these signs of rage are probably in large part, and some of them appear to be wholly, due to the direct action of the excited sensorium.

But animals of all kinds, and their progenitors before them, when attacked or threatened by an enemy, have exerted their utmost powers in fighting and in defending themselves. Unless an animal does thus act, or has the intention, or at least the desire, to attack its enemy, it cannot properly be said to be enraged.

An inherited habit of muscular exertion will thus have been gained in association with rage; and this will directly or indirectly affect various organs, in nearly the same manner as does great bodily suffering.

 

[9] I am much indebted to Mr. A. H. Garrod for having informed me of M. Lorain’s work on the pulse, in which a sphygmogram of a woman in a rage is given; and this shows much difference in the rate and other characters from that of the same woman in her ordinary state.

 

The heart no doubt will likewise be affected in a direct manner; but it will also in all probability be affected through habit; and all the more so from not being under the control of the will.

We know that any great exertion which we voluntarily make, affects the heart, through mechanical and other principles which need not here be considered; and it was shown in the first chapter that nerve-force flows readily through habitually used channels,—through the nerves of voluntary or involuntary movement, and through those of sensation.

Thus even a moderate amount of exertion will tend to act on the heart; and on the principle of association, of which so many instances have been given, we may feel nearly sure that any sensation or emotion, as great pain or rage, which has habitually led to much muscular action, will immediately influence the flow of nerve-force to the heart, although there may not be at the time any muscular exertion.

 

The heart, as I have said, will be all the more readily affected through habitual associations, as it is not under the control of the will.

A man when moderately angry, or even when enraged, may command the movements of his body, but he cannot prevent his heart from beating rapidly.

His chest will perhaps give a few heaves, and his nostrils just quiver, for the movements of respiration are only in part voluntary.

In like manner those muscles of the face which are least obedient to the will, will sometimes alone betray a slight and passing emotion.

The glands again are wholly independent of the will, and a man suffering from grief may command his features, but cannot always prevent the tears from coming into his eyes. A hungry man, if tempting food is placed before him, may not show his hunger by any outward gesture, but he cannot check the secretion of saliva.

 

Under a transport of Joy or of vivid Pleasure, there is a strong tendency to various purposeless movements, and to the utterance of various sounds.

We see this in our young children, in their loud laughter, clapping of hands, and jumping for joy; in the bounding and barking of a dog when going out to walk with his master; and in the frisking of a horse when turned out into an open field. Joy quickens the circulation, and this stimulates the brain, which again reacts on the whole body.

The above purposeless movements and increased heart-action may be attributed in chief part to the excited state of the sensorium,[10]

and to the consequent undirected overflow, as Mr. Herbert Spencer insists, of nerve-force. It deserves notice, that it is chiefly the anticipation of a pleasure, and not its actual enjoyment, which leads to purposeless and extravagant movements of the body, and to the utterance of various sounds.

We see this in our children when they expect any great pleasure or treat; and dogs, which have been bounding about at [10] How powerfully intense joy excites the brain, and how the brain reacts on the body, is well shown in the rare cases of Psychical Intoxication. Dr. J. Crichton Browne (`Medical Mirror,’

1865) records the case of a young man of strongly nervous temperament, who, on hearing by a telegram that a fortune had been bequeathed him, first became pale, then exhilarated, and soon in the highest spirits, but flushed and very restless. He then took a walk with a friend for the sake of tranquillising himself, but returned staggering in his gait, uproariously laughing, yet irritable in temper, incessantly talking, and singing loudly in the public streets.

It was positively ascertained that he had not touched any spirituous liquor, though every one thought that he was intoxicated.

Vomiting after a time came on, and the half-digested contents of his stomach were examined, but no odour of alcohol could be detected.

He then slept heavily, and on awaking was well, except that he suffered from headache, nausea, and prostration of strength.

the sight of a plate of food, when they get it do not show their delight by any outward sign, not even by wagging their tails.

Now with animals of all kinds, the acquirement of almost all their pleasures, with the exception of those of warmth and rest, are associated, and have long been associated with active movements, as in the hunting or search for food,