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 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 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 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. 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.