IX. THE MEANING OF INFANCY
The great discovery of John Fiske as to the reasons for the long continuance of childhood in man must not be overlooked in this connection; it bears so directly on health and efficiency, and is closely associated with the importance of the family to the individual as well as to the nation. Why, it may be asked, is man’s period of helplessness so prolonged; why, when his brain development reaches so high a standard, is he for years in a position of entire dependence, whereas snakelet and chick are practically self-supporting from the hour of hatching? When the lower forms of animal life are compared with mankind, the non-existence in their case of any such stage as infancy is at once apparent. They are brought into the world able to take care of themselves and to live an independent individual existence. Young pigs run almost as soon as they are born, young swallows fly directly they are fledged.
Now, if the structure of lower animals be examined, it will be found that they have no central warehouse corresponding to the human brain for the storage of new sensations or for an elaborate and original response to them. Each such animal repeats the life of its parents; each responds in exactly the same way to the contact of air, of earth, of food, or of water. Their activities, it is true, are distinguished by accuracy and despatch, but the offspring of a hen of the twentieth century has no larger capacity for the variation of these 243 activities than has the chick which was hatched out six thousand years ago. The guinea-pig of to-day, for example, remains mentally at the level of his thousandth ancestor. Wherein then lies the difference between the pig and the baby?
As animals rise in the scale, as their brains become more subtle, more elaborate in structure, their actions become correspondingly more numerous and complicated, more varied, more individual. The nervous systems of such animals are characterised by an increasing complexity of development, and this provides the machinery necessary to the performance of an increasing number of muscular and mental co-ordinations; they can adapt themselves to unfamiliar surroundings and possess much enhanced advantages in the struggle for existence. But, associated with these advantages, is a much longer period of immaturity, because, where the capacity for flexibility and progress is great, the antenatal period is insufficient for the establishment of the necessary nervous connections or even for the development of the brain cells between which these connections will be formed. The chick will have its full plumage in ten weeks, but mentally it is far below a dog or a monkey, whose period of immaturity is much longer. Similarly, the dog attains his maturity long before the monkey, who is infinitely his superior in fertility of resource, power to learn through imitation, and capacity for attention. The infant in its turn is far longer in a dependent condition than the highest ape.
Relatively large in bulk at birth, and reaching usually its full mass in the first fourteen years of life, the human brain possesses throughout childhood vast silent areas, big with future potentialities, areas in which the cells are slowly ripening to function. Even after full growth in size is reached, many more years must pass before capacity for the higher mental functions or for the complete control of such functions has developed. It must be borne in mind that, throughout this period of immaturity, errors of nutrition or defective stimulation may interfere with function. One of the most important duties of the home is to provide the suited environment for its child occupants during these long and anxious years. How long they are has been emphasised by Dr. Clouston,[106] who has said that, of all the periods of brain growth, the most important, as regards the development of our highest moral and mental potentialities, is that between eighteen and twenty-five years of age, when the capacity for self-control should be coming into function in its highest relations, and when failure to ripen in due course is fraught with most serious consequences for the future.
There is no such thing, therefore, as infancy or parental care in the lowest orders of animal life; of which, one result is a gigantic mortality among their offspring. Enormous numbers of eggs are laid to ensure the preservation of 245 the species when left to fend for themselves. The turbot, for instance, must deposit millions of minute glassy ova or the species would become extinct. Even among frogs the destruction of tadpoles is so great that provision must be made to allow for this loss. The fostering care of birds for their young at once permits a great reduction in the number of the offspring; but, though birds give evidence of some capacity for parental care, infancy, as such, is really confined to mammalian young. Even here it is curtailed in a vast number of species; but wherever it exists it stands for power to progress, and represents capacity for benefiting by, indeed depending upon, education, if only in the simple form of learning by imitation—a form familiar to readers of such books as Long’s “Schools of the Woods.”
Plasticity is the hall-mark of progress; educability indicates a brain more or less competent to assimilate, to remember, to compare, to discriminate. This door of progress has been merely set ajar for even the higher apes; it is open to man only. The period of plasticity is evidently prolonged in proportion to the degree in which conscious intelligence has superseded mere brute force in promoting successful survival—that is to say, the transmission of mental ability rather than of physical strength postpones maturity. Man alone possesses in full the powers of selection and adaptation, of reason and of emotion, of memory and of mental originality, which are 246 included in his rich heritage of life. If he is to realise his full potentialities, he must have protection for years after birth and an extended time for development. The immature infant must be fed, sheltered, and stimulated, if the inherent powers of adjustment to surroundings are to develop normally. But so great is the instability associated with human immaturity and future potentiality, that arrested development is too often the heavy penalty paid by the child for the ignorance and carelessness of his parents.[107] Faults of food and clothing, insufficient warmth, cleanliness, or exercise, premature work or precocious responsibility and independence, prolonged overstrain or insufficient stimulation of mind and body, are the prevalent causes by which a child’s normal growth is warped and prejudiced. 247 Where this occurs he never enters into his birthright of power; it has too often been thoughtlessly bartered by his natural guardians, literally for a mere mess of pottage.