Part 2
The organs are differently placed within the body, and even differently formed. The bony structure is everywhere soft and unfinished, the plates of the skull imperfectly fitted together, with gaps at the corners; and it is well that they are, for if the brain box were closed tight the brain within could never grow. Surgeons have lately even made artificial openings where the skull was prematurely perfect, to save the baby from idiocy. The bony inclosures of the middle ear are quite unfinished, so that on the one side catarrhal inflammations from the nose and throat travel up to the ear more readily than in later life, while on the other side ear inflammations are more likely to pass into the brain. The spine is straight, like an ape’s, instead of having the double curve of human-kind, which seems to be brought about by the pull of the muscles after we have come to stand erect.
I have quoted these details from Oppenheim, and from Vierordt’s and Roberts’s measurements, as given by Dr. Burk (“Growth of Children in Height and Weight.”) Some of the figures are given otherwise by other authorities. I might fill many pages with similar details. Some of these differences do not disappear till full manhood, others are gone in a few weeks after birth. And in them all there is so constant a repetition of lower animal forms that anatomists are brought to a confidence in the “recapitulation doctrine,” such as they can hardly give to others by means of a few sample facts.
The most curious of all the monkey traits shown by the new-born baby is the one investigated by Dr. Louis Robinson (“Nineteenth Century,” November, 1891). It was suggested by “The Luck of Roaring Camp.” The question was raised in conversation whether a limp and molluscous baby, unable so much as to hold up its head on its helpless little neck, could do anything so positive as to “rastle with” Kentuck’s finger; and the more knowing persons present insisted that a young baby does, as a matter of fact, have a good firm hand-clasp. It occurred to Dr. Robinson that if this was true it was a beautiful Darwinian point, for clinging and swinging by the arms would naturally have been a specialty with our ancestors if they ever lived a monkey-like life in the trees. The baby that could cling best to its mother as she used hands, feet, and tail to flee in the best time over the trees, or to get at the more inaccessible fruits and eggs in time of scarcity, would be the baby that lived to bequeath his traits to his descendants; so that to this day our housed and cradled human babies would keep in their clinging powers a reminiscence of our wild treetop days.
Dr. Robinson was fortunate enough to be able to test his theory on some sixty babies in the first hours of their life, and was triumphantly successful. He clasped their hands about a slender rod, and they swung from it like athletes, without apparent discomfort, by the half minute; many of us grown people could not do as well. Such a remarkable power of hands and arms has for ages been of no especial use to the human race, and it fades out in a few weeks, but for many months the arms keep ahead of the legs in development.
Here was not only strength of arms, but the ability to perform quite skillfully an action, that required the working together of a number of muscles to a definite end,--the action namely, of clasping an object with the hand. This is one of several actions that come ready-made to the baby at birth, before he can possibly have had any chance to learn them, or any idea of what they are for. Babies sneeze, swallow, and cry on the first day; they shut their eyes at a bright light, or at a touch. On the first day, moreover, they have been seen to start at a sound or a jar; Preyer observed hiccoughing, choking, coughing, and spreading the toes when the soles were tickled; and Darwin saw yawning and stretching within the first week, though I do not know that any one has seen it on the first day.
These movements are all of the class called reflex,--movements, that is, in which the bodily mechanism is set off by some outside action on the senses, as a gun is set off by a touch on the trigger. Thus, when a tickling affects the mucous membrane, a sneeze executes itself without any will of ours; when our sense of sight perceives a swift missile coming, the neck muscles mechanically jerk the head to one side.
We grown people have, however, a good deal of power of holding in our reflexes,--“inhibiting” them, as the technical expression is,--but the baby has none at all. If they had a highly developed reflex activity, babies would be in real danger from the unrestrained acts of their own muscles, as we see in the case of convulsions, which show reflex action at its extreme. But the actions I have mentioned are about all the reflex movements that have been noted in new-born babies, except what are called the periodic reflexes, such as breathing, the heartbeat, the contractions of the arteries, and all the regular muscular actions of organic life.
That so complex a system of movement as these periodic reflexes should be so readily touched into motion upon contact with air and food, to maintain itself afterward by the interplay of the bodily mechanism and external forces, shows a ready-made hereditary activity far more than the sudden reflexes do. It does not work quite smoothly at first, however: the establishment of breathing, for instance, is irregular, and often difficult. Even the sudden reflexes are slower and less perfect than with older people.
There is another class of movements, often confused with the reflex--that is, instinctive movements. Real grasping (as distinguished from reflex grasping), biting, standing, walking, are examples of this class. They are race movements, the habits of the species to which the animal belongs, and every normal member of the species is bound to come to them; yet they are not so fixed in the bodily mechanism as the reflex movements. The stimulus to them seems to come more from within than from without--yet not from reason and will, but from some blind impulse. This impulse is usually imperfect, and the child has to work his own way to the mastery of the movements. Yet though certain reflex activities are inherited in a more highly developed condition than any human instincts, the instincts are at bottom _always_ hereditary, which is not the case with the reflexes--any one may teach his muscles new reflex movements, unknown to his ancestors. A musician does it every time that he practices new music till his hands will run it off of their own accord, while he is thinking of something else. But instinct cannot be thus acquired.
The amazing instincts of the lower animals; the imperfect and broken condition of the instincts in man, yet the deep hold that they have on him; the mingling of inherited necessity and individual freedom in the way in which they are worked out; the mystery of the physiological method by which they act (while that of reflex movement is fairly well understood, up to a certain point); the light they seem always about to shed for the biologist on the profoundest problems of heredity, and for the philosopher on those of free will and personality,--these things make instinct one of the great fields of present research, and I must not venture into it, though it is of importance in trying to understand a baby.
I shall say only that while instinct does not appear in the lowest animals (whose action is all of the reflex type), and is for a time a sign of rising rank in the scale of life, it reaches its culmination with the insects, and as we approach man it is the breaking up of the instincts that is in its turn a sign of advancement to higher life. The little chicken runs about as soon as it is out of its shell, and even the monkey baby is able to take care of itself in a few months. Nothing is so helpless as the human baby, and in that helplessness is our glory, for it means that the activities of the race (as John Fiske has so clearly shown) have become too many, too complex, too infrequently repeated, to become fixed in the nervous structure before birth; hence the long period after birth before the child comes to full human powers. It is a maxim of biology (as well as the frequent lesson of common observation) that while an organism is thus immature and plastic, it may learn, it may change, it may rise to higher development; and thus to infancy we owe the rank of the human race.
The one instinct the human baby always brings into the world already developed is half a mere reflex act--that of sucking. It is started as a reflex would be, by the touch of some object, pencil, finger, or nipple, it may be, between the lips; but it does not act like a reflex after that. It continues and ceases without reference to this external stimulus, and a little later often begins without it, or fails to begin when the stimulus is given. If it has originally a reflex character, that character fades out, and leaves it a pure instinct.
These two types of automatic movement (for instinct, however complicated later with volition, gives rise in these earliest days to none but automatic movement) are both “purposive,” though not purposed--that is, they are actions that are plainly adapted to some end by ancestral intelligence or by natural selection. But there was another type of movements more conspicuous in our baby than either, and apparently quite nonpurposive. From the first day she moved slightly, but almost constantly, the legs drawing up, the arms stirring, the eyes and head rolling a little. Sometimes the features were distorted with vague and meaningless grimaces. Most other observers report these movements, and inexperienced ones say that the baby “felt with his hands about his face,” or “tried to get his hands to his head.” Any mother may convince herself that the baby has no will in the matter by watching till he really does begin to try, weeks later, to turn his head, put his hands to his mouth, kick up his legs: the difference in the whole manner of the action is evident.
An odd explanation has been offered for these movements by Dr. Mumford, an English physiologist. He holds that they have a singular resemblance to those of swimming amphibians; that their prototype may be seen in any aquarium; they are, in short, survivals of the period long before the ape-like stage, long before any mammalian stage, when our ancestors had not yet abandoned life in the waters.
Now, although it is quite true that biologists believe that if our ancestry is traced far enough, it does lead back to the water, still it seems hardly possible that in a human baby, whose structure passed the amphibian stage long before birth, the most frequent movements should hark back to that tremendous antiquity. It is more likely that Preyer’s explanation is the correct one: viz., that the movements are simply due to the rapid growth of nerve centres, which causes an overflow of nervous force to the muscles and makes them contract at haphazard. A certain regularity is given to these chance movements by the tendency of nerve impulse to flow in the same paths where it has flowed before, rather than in new ones, so that the muscles are drawn toward the position they occupied before birth. This brings the hands constantly up about the head--a fact that later has important results in development.
These aimless movements are called “impulsive” by Preyer. I have followed Bain and Mrs. Moore in calling them “spontaneous.”
There were no movements beyond these three types, and therefore none that showed the least volition. Mothers often think the crying shows wish, will, or understanding of some sort. But Preyer tells us that babies born without a brain cry in just the same manner.
Mothers do not like to think that the baby is at first an automaton; and they would be quite right in objecting if that meant that he was a mere machine. He is an automaton in the sense that he has practically neither thought, wish, nor will; but he is a living, conscious automaton, and that makes all the difference in the world. And it would be a bold psychologist who should try to say what _germ_ of thought and will lies enfolded in his helplessness. Certainly, the capacity of developing will is there, and an automaton with such a capacity is a more wonderful creature than the wise, thinking, willing baby of nursery tradition would be.
If mothers would only reflect how little developed a baby’s mind is at a year old, after all the progress of twelve months, they would see that they rate the mental starting point altogether too high. And they miss thus the whole drama of the swift and lovely unfolding of the soul from its invisible germ--a drama that sometimes fairly catches one’s breath in the throat with excitement and wonder.
III
THE NEW-BORN BABY: SENSATIONS AND CONSCIOUSNESS.
I have said that the baby began the world as an automaton, but a conscious, feeling automaton. And what, then, were these feelings and this consciousness? What was the outfit for beginning the world that the little mind brought with it? When I asked such questions I was skirting the edge of one of the great battle-grounds of philosophy. Whether all human ideas are made up solely from one’s own experience of the outer world as given him by his senses, or whether there are, on the contrary, inborn ideas, implanted directly by nature or God,--this is a question on which volumes have been written.
Did the baby start out ready equipped with ideas of space, personal identity, time, causation, such as we find so ineradicable in our own minds? That is, did she see objects about her, located in space, nearer and farther, right and left, and all outside and separate from herself, as we do? hear sounds coming from without, as we do? Did she feel herself a separate thing from the outer world? Did she perceive events as happening in time succession, one after another? And did she think of one thing as happening because of another, so that, for instance, she was capable of crying in order to cause her dinner to be brought?
The hope of answering such questions was the first stimulus to the study of infants, and the earlier records are much occupied with them. Philosophers nowadays are less disposed to think that we can prove anything about the doctrine of innate ideas by finding whether babies have such ideas to begin with; for we might indeed have ideas that came direct from God, or from the nature of the mind, and yet might not enter into our inheritance of these at once.
To me, however, not seeking to solve philosophical problems, but only to watch and comprehend what was going on in the baby’s mind, it was none the less interesting to try to make out the condition of her senses and consciousness--though without the careful special investigations certain physiologists had made before, I should have found it blind guessing as to how much she really did see, hear, and feel; for these processes, of course, went on inside her little mind, and could only be inferred from her behavior.
She evidently felt a difference between light and darkness from the first hour, for she stopped crying when her face was exposed to gentle light; and other observers confirm this. Two or three report also a turning of the head toward the light within the first week. The nurse, who was intelligent and exact, thought she saw this in the case of my niece. I did not, but I saw instead a constant turning of the eyes toward a person coming near her--that is, toward a large dark mass that interrupted the light. Either movement must be regarded as entirely instinctive or reflex. Even plants will turn toward the light, and among animal movements this is one of the most primitive; while the habit of looking toward any dark moving mass runs far back in animal history, and may well have become fixed in the bodily mechanism. With the beginning of voluntary looking these instinctive movements fade.
No other sign of vision appeared in the little one during the first fortnight. The eyes were directed to nothing, fixed on nothing. They did not wink if one made a pass at them. There was no change of focus for near or distant seeing; the two eyes did not even move always in unison,--and as the lids also had by no means learned yet to move symmetrically with the balls and with each other, some extraordinary and alarming contortions resulted.
True seeing, such as we ourselves have, is not just a matter of opening the eyes and letting the vision pour in; it requires a great deal of minute muscular adjustment, both of the eyeballs and of the lenses, and it is impossible that a baby should see anything but blurs of light and dark (without even any distinction of distance) till he has learned the adjustments. Not colored blurs, but light and dark only, for no trace of color sense has ever been detected within the first fortnight of life, no certain evidence of it even within the first year.
The baby showed no sign of hearing anything until the third day, when she started violently at the sound of tearing paper, some eight feet from her. After that, occasional harsh or sudden sounds--oftener the rustling of paper than anything else--could make her start or cry.
It is well established by the careful tests of several physiologists that babies are deaf for a period lasting from several hours to several days after birth. The outer tube of the ear is often closed by its own walls, and the middle ear is always stopped up with fluid. Even after the ear itself is clear and ready for hearing, few sounds are noticed; perhaps because the outer passage is still so narrow, perhaps because of imperfect nerve connections with the brain, perhaps because sounds are not distinguished, but go all together into a sort of blur, just as the sights do. As the usual effect of sounds on wee babies is to startle them, and to set off convulsive reflex movements, it is well for them that hearing is so tardy in development.
There is noticeable variation in sensitiveness to hearing, not only among different babies, but in the same baby at different times. A sound that startles on one day seems to pass absolutely unheard on the next.
In observing the sensibility to sound, one may easily be misled. If a baby starts when a door slams or a heavy object falls, it is more likely to be the jar than the sound that affects him; if he becomes restless when one claps the hands or speaks, it may be because he felt a puff of air on his head. The tap of an ordinary call bell is a good sound to test with, causing neither jar nor air current.
Taste and smell were senses that the baby gave no sign of owning till much later. The satisfaction of hunger was quite enough to account for the contentment she showed in nursing; and when she was not hungry she would suck the most tasteless object as cheerfully as any other. Physiologists, however, have had the daring to make careful test of smell and taste in the new-born, putting a wee drop of quinine, sugar, salt, or acid solution on the babies’ tongues, and strong odors to their noses, and have been made certain by the resulting behavior that these senses do exist from the first. But it requires rather strong tests to call them into action. Many babies, for instance, suck at a two per cent. solution of quinine as if it were sugar; so it seems unlikely that the mild and monotonous taste of milk, and the neutral smells by which any well-kept baby is surrounded, are really perceived at all. There are instances related of very positive discrimination between one milk and another, either by taste or smell, shown by very young babies; yet the weight of evidence points to an almost dormant condition of these two senses.
We were told in school that the fifth sense was “feeling,” but psychologists now regard this not as a single sense, but as a group, called the “dermal” or skin senses. The sense of touch and pressure, the senses of heat and cold, and the sense of pain are the principal ones of the group.
Our baby showed from the first that she was aware when she was touched. She stopped crying when she was cuddled or patted. She showed comfort in the bath, which may have been in part due to freedom from the contact of clothes, and to liking for the soft touches of the water. She responded with sucking motions to the first touch of the nipple on her lips. Preyer found the lips of new-born babies quite delicately sensitive, responding even to the lightest touch; and there are other sensitive spots, such as the nostrils and the soles of the feet.
On the whole, however, the rose-leaf baby skin proves to be much less sensitive than ours, not only to contact, but also to pain, and perhaps to heat and cold, though this has not been so thoroughly tested. This is not saying, of course, that the physiological effects of heat and cold upon the baby are unimportant.
Our baby had no experience of skin pain in her early days, and being kept at an equable temperature, probably received no definite sensations either of heat or of cold.
The foregoing are the “special senses,” that is, those that give impressions of external things, and have end organs to receive and make definite these impressions,--the eye at the end of the optic nerve, the different kinds of nerve tips in the skin, and so forth. Another sense now claims almost to rank with them,--the recently studied sense of equilibrium and motion, by which we feel loss of balance in our bodies and changes in their motion (changes only, for no one can feel perfectly smooth motion). This sense has been traced to the semicircular canals of the ear; and as this part of the ear is the oldest in evolution, and the rudimentary ears of the lower orders of animals are quite analogous to it in structure, biologists now suspect that hearing may be a more recent sense than we have thought, and that much which has been taken for sense of sound in the lower animals--even as high as fishes--may perhaps be only a delicate sense of motion.
I failed to watch for this motion sense in the baby. It would have been shown by signs that she felt change of motion when she was lifted and moved. Equilibrium sense she must have used as soon as she began to balance her little head, but in the first limp and passive days there was no sign of it. Still, there are tales of very young babies who showed disturbance, as if from a feeling of lost equilibrium, when they were lowered swiftly in the arms.
There is besides a sort of sensibility to vibration that affects the whole body. We know how much of the rhythm of music may be caught quite soundlessly through, the vibrations of the floor; and it is said (perhaps not altogether credibly) that it was thus that Jessie Brown recognized even the instruments and the tune at the relief of Lucknow by the tremor along the ground before a sound was audible. A jar, affecting the whole body, seems to be felt by creatures of very low organization. Babies are undoubtedly quite susceptible to jarring from the earliest days. Champney’s baby started when the scale of the balance in which he was lying immediately after birth sprang up.
Then there is the “muscle sense”--the feeling of the action of our own muscles; and a most delicate and important sense this is. It is safe to say that the baby had it from the first, and felt the involuntary movements her own little body was making, for it is hardly conceivable how else she could have learned to make voluntary ones. But that is another story, and comes later.