The biography of a baby

by Milicent Washburn Shinn

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.