VI.—THE PHYSIOLOGY OF HABIT
A work of Dr Carpenter’s was perhaps the first which gave me the clue I was in search of. In his Mental Physiology—a most interesting book,
by the way—he works out the analogy between mental and physical activity, and shows that the correspondence in effect is due to a correspondence in cause.
Growing Tissues form themselves to Modes of Action.—To state roughly the doctrine of the school Dr Carpenter represents—the tissues, as muscular tissue, for instance, undergo constant waste and as constant reparation. Even those modes of muscular action which we regard as natural to us, as walking and standing erect, are in reality the results of a laborious education; quite as much so as many modes of action which we consciously acquire, as writing or dancing; but the acquired modes become perfectly easy and natural. Why? Because it is the law of the constantly growing tissues that they should form themselves according to the modes of action required of them. In a case where the brain is repeatedly sending down to the muscles, under nervous control as they are, the message to have a certain action done, that action becomes automatic in the lower centre, and the faintest suggestion from outside comes to produce it without the intervention of the brain. Thus, the joints and muscles of the child’s hand very soon accommodate themselves to the mode of action required of them in holding and guiding the pen. Observe, it is not that the child learns with his mind how to use his pen, in spite of his muscles; but that the newly growing muscles themselves take form according to the action required of them. And here is the explanation of all the mountebank feats which appear simply impossible to the untrained looker-on. They are impossible to him, because his joints and muscles have not the same powers which
have been produced in the mountebank by a process of early training.
Therefore Children should learn Dancing, Swimming, etc., at an Early Age.—So much for mere bodily activities. And here we have the reason why children should learn dancing, riding, swimming, calisthenics, every form of activity which requires a training of the muscles, at an early age: the fact being, that muscles and joints have not merely to conform themselves to new uses, but to grow to a modified pattern; and this growth and adaptation take place with the greatest facility in early youth. Of course, the man whose muscles have kept the habit of adaptation picks up new games, new muscular exercises, without very great labour. But teach a ploughman to write, and you see the enormous physical difficulty which unaccustomed muscles have in growing to any new sort of effort. Here we see how important it is to keep watch over the habits of enunciation, carriage of the head, and so on, which the child is forming hour by hour. The poke, the stoop, the indistinct utterance, is not a mere trick to be left off at pleasure ‘when he is older and knows better,’ but is all the time growing into him becoming a part of himself, because it is registered in the very substance of his spinal cord. The part of his nervous system where consciousness resides (the brain) has long ago given a standing order, and such are the complications of the administration, that to recall the order would mean the absolute re-making of the parts concerned. And to correct bad habits of speaking, for instance, it will not be enough for the child to intend to speak plainly and to try to speak plainly; he will not be able to do so habitually until some degree
of new growth has taken place in the organs of voice whilst he is making efforts to form the new habit.
Moral and Mental Habits make their Mark upon Physical Tissues.—But, practically, everybody knows that the body, and every part of the body, accommodates itself very readily to the uses it is put to: we know that if a child accustom herself to stand on one foot, thus pushing up one shoulder, the habit will probably end in curvature of the spine; that to permit drooping shoulders, and, consequently, contracted chest, is to prepare the way for lung disease. The physical consequences of bad habits of this sort are so evident, that we cannot blind ourselves to the relation of cause and effect. What we are less prepared to admit is, that habits which do not appear to be in any sense physical—a flippant habit, a truthful habit, an orderly habit—should also make their mark upon a physical tissue, and that it is to this physical effect the enormous strength of habit is probably due. Yet when we consider that the brain, the physical brain, is the exceedingly delicate organ by means of which we think and feel and desire, love and hate and worship, it is not surprising that that organ should be modified by the work it has to do; to put the matter picturesquely, it is as if every familiar train of thought made a rut in the nervous substance of the brain into which the thoughts run lightly of their own accord, and out of which they can only be got by an effort of will.
Persistent Trains of Thought.—Thus, the mistress of the house knows that when her thoughts are free to take their own course, they run to cares of the house or the larder, to to-morrow’s dinner or the winter’s clothing; that is, thought runs into the rut
which has been, so to speak, worn for it by constant repetition. The mother’s thoughts run on her children, the painter’s on pictures, the poet’s on poems; those of the anxious head of the house on money cares, it may be, until in times of unusual pressure the thoughts beat, beat, beat in that well-worn rut of ways and means, and decline to run in any other channel, till the poor man loses his reason, simply because he cannot get his thoughts out of that one channel made in the substance of his brain. And, indeed, “that way madness lies” for every one of us, in the persistent preying of any one train of thought upon the brain tissue. Pride, resentment, jealousy, an invention that a man has laboured over, an opinion he has conceived, any line of thought which he has no longer the power to divert, will endanger a man’s sanity.
Incessant Regeneration of Brain Tissue.—If we love, hate, think, feel, worship, at the expense of actual physical effort on the part of the brain, and consequent waste of tissue, how enormous must be the labour of that organ with which we, in fact, do everything, even many of those acts whose final execution falls to the hands or feet! It is true: and to repair this excessive waste, the brain consumes the lion’s share of the nourishment provided for the body. As we have already seen, fully a sixth or a fifth of all the blood in the body goes to repair the waste in the king’s house; in other words, new brain tissue is being constantly formed at a startlingly rapid rate: one wonders at what age the child has no longer any part left of that brain with which he was born.
The new tissue repeats the old, but not quite exactly. Just as a new muscular growth adapts itself to any new exercise required of it, so the new brain
tissue is supposed to ‘grow to’ any habit of thought in force during the time of growth—‘thought’ here including, of course, every exercise of mind and soul. “The cerebrum of man grows to the modes of thought in which it is habitually exercised,” says an able physiologist; or, in the words of Dr Carpenter, “Any sequence of mental action which has been frequently repeated, tends to perpetuate itself; so that we find ourselves automatically prompted to think, feel, or do what we have been before accustomed to think, feel, or do, under like circumstances, without any consciously formed purpose or anticipation of results. For there is no reason to regard the cerebrum as an exception to the general principle, that whilst each part of the organism tends to form itself in accordance with the mode in which it is habitually exercised, this tendency will be specially strong in the nervous apparatus, in virtue of that incessant regeneration which is the very condition of its functional activity. It scarcely, indeed, admits of a doubt, that every state of ideational consciousness which is either very strong or is habitually repeated, leaves an organic impression on the cerebrum, in virtue of which the same state may be reproduced at any future time in correspondence to a suggestion fitted to excite it.”
Artificial Reflex Actions may be Acquired.—Or, to take Huxley’s way of putting the case:—
“By the help of the brain we may acquire an infinity of artificial reflex actions; that is to say, an action may require all our attention and all our volition for its first, second, or third performance, but by frequent repetition it becomes, in a manner, part of our organisation, and is performed without volition or even consciousness.
“As every one knows, it takes a soldier a long time to learn his drill—for instance, to put himself into the attitude of ‘attention’ at the instant the word of command is heard. But after a time the sound of the word gives rise to the act, whether the soldier be thinking of it or not. There is a story, which is credible enough, though it may not be true, of a practical joker who, seeing a discharged veteran carrying home his dinner, suddenly called out ‘Attention!’ whereupon the man instantly brought his hands down, and lost his mutton and potatoes in the gutter. The drill had been thorough, and its effects had become embodied in the man’s nervous structure.
“The possibility of all education (of which military drill is only one particular form) is based upon the existence of this power which the nervous system possesses, of organizing conscious actions into more or less unconscious, or reflex, operations. It may be down laid as a rule, that if any two mental states be called up together, or in succession, with due frequency and vividness, the subsequent production of the one of them will suffice to call up the other, and that whether we desire it or not.
Intellectual and Moral Education.—“The object of intellectual education is to create such indissoluble associations of our ideas of things, in the order and relation in which they occur in nature; that of a moral education is to unite as fixedly, the ideas of evil deeds with those of pain and degradation, and of good actions with those of pleasure and nobleness.”
But it is the intimate interlocking of mind and matter which is more directly important to the educator—the idea which we have put broadly under the (by no means scientifically accurate) figure of
a rut. Given, that the constant direction of the thoughts produces a certain set in the tissues of the brain, this set is the first trace of the rut orpath, a line of least resistance, along which the same impression, made another time, will find it easier to travel than to take another path. So arises a right-of-way for any given habit of action or thought.
Character affected by Acquired Modification of Brain Tissue.—What follows? Why, that the actual conformation of the child’s brain depends upon the habits which the parents permit or encourage; and that the habits of the child produce the character of the man, because certain mental habitudes once set up, their nature is to go on for ever unless they should be displaced by other habits. Here is an end to the easy philosophy of, ‘It doesn’t matter,’ ‘Oh, he’ll grow out of it,’ ‘He’ll know better by-and-by,’ ‘He’s so young, what can we expect?’ and so on. Every day, every hour, the parents are either passively or actively forming those habits in their children upon which, more than upon anything else, future character and conduct depend.
Outside Influence.—And here comes in the consideration of outside influence. Nine times out of ten we begin to do a thing because we see some one else do it; we go on doing it, and—there is the habit! If it is so easy for ourselves to take up a new habit, it is tenfold as easy for the children; and this is the real difficulty in the matter of the education of habit. It is necessary that the mother be always on the alert to nip in the bud the bad habit her children may be in the act of picking up from servants or from other children.