Part 6

Rats, of course, are used to running thru holes in the walls of houses, drain pipes, and the like, and are clever enough at finding their way in such places. So this man made a set of passages, such as a rat would naturally live in, and put seven rats in it. These soon became at home, and would find their way at once thru the maze of passages to the spot where their food was kept, running at full speed. Then the man took a long straight passage with a sharp turn at the end, and shortened it up by three feet. The next time the rats were put in, they all started pell-mell for their food; but when they came to the shortened passage, tho it was broad day light, every one of the rats ran smash against the end wall; and it actually took as long for them to learn that the length of the passage had been changed, as it took to learn the way round in the first place. But when the passage was made longer than before, the rats ran their customary distance to the place where the side opening used to be; then turned and butted into the side wall. This they did time after time, and even after they had learned to turn at the right point one day, they were just as likely to butt the wall the next. Really, they did not seem able to think about the matter at all.

But I am saving the strangest case for the last. This is about a cow. The cow used to make a great deal of fuss for her owner because she would not stand to be milked unless she were allowed all the while to lick her calf. One day the calf died; then there was much trouble, and no milk at all. But the farmer understood the ways of cows. He took the calf’s skin, stuffed it with hay, and gave the mother that to lick at milking time. To be sure, the stuffed calf had neither head nor legs and didn’t look the least bit like a calf—but it was all right to lick, and the mother cow licked it contentedly and gave down her milk as before. One day, when the tender parent was caressing her little calf at milking time, she happened to unrip the seam where the skin was sewed up. The hay fell out; and the mother cow, without the slightest surprise or agitation, proceeded to devour the unexpected provender, and never left off until the little hay calf had entirely disappeared down her throat.

I understand that this practice of giving a cow the stuffed skin of its calf is the regular thing in some countries, where the cattle are wilder than with us. I am told also that a like device has to be employed with camels. Each camel refuses to be milked, unless she can have her little one to lick. But the natives are accustomed to kill and eat the little camel, and give the mother its skin. This answers exactly as well; but if they try to palm off another skin on her, she knows the difference at once. Out of a hundred living camel-calves or their stuffed skins, the mother camel will always pick her own, and never be content with any other. Yet she doesn’t bother her head over the difference between her live calf, and its dead skin lacking legs and head, with the hay stuffing sticking out of the seams! Truly, animals are as stupid about some matters as they are wise about others.

XVII

How We Differ From The Animals

How do we differ from all other living creatures? Not in having hands; the monkeys have four hands, and if hands were the test of humanity, would be twice as human as we. Not in lacking coats of fur or features; pigs and elephants have skins as bare as ours. Nor is it that we walk on two legs; the birds do that, and the kangaroos. The difference is not even in the fact that we have no tails; for some of the apes also are as tailless as we are. Besides, when you come to think of it, most animals do not have tails—insects do not, nor clams and oysters, nor sea-anemones and star-fish, nor corals and sponges, nor frogs and toads, nor jelly-fish; even the birds, unless you count the feathers as part, do not have tails that one could really wag.

After all, too, we human beings do have tails; or at least a string of tail bones, an inch or more long, tucked away inside our skins. This coccyx bone, as it is called, is the place where it hurts so fearsomely when you sit down too hard on a pebble or a bicycle bar, and it catches you in one little spot just at the end of the back bone. When that happens, you may remember that the difference between you and the animals is not altogether in tail bones. Once in a while, too, men do have veritable tails, as large as a finger, and round and curly like a pig’s.

The one essential difference between ourselves and all other creatures on the earth is neither in hands nor skins nor legs nor tails, but in talking. We can talk and the animals cannot.

But you say right off, parrots can talk. Oh, no, they can’t! Parrots can speak, in the sense that they can say words; but that is a quite different thing from talking. Dumb people, tho they cannot speak, have no difficulty in learning to talk with their fingers. The parrot can be taught to repeat words, whole sentences, even pieces of poetry—but no parrot ever learns to talk about the things that he is interested in. No parrot, for example, ever tries to tell about the forest where he was born, nor his voyage to this country, nor the animals he met in the store before he was bought. He, says “Polly wants a cracker”; but he doesn’t say, “I want to get out of this cage and fly about”; and no two parrots ever yet tried to converse with one another.

How different it is with children. They try to talk long before they can. They pick up words for themselves. They talk with one another; and when they don’t know the word for something they want to say, they make one up. Don’t you remember various words that you and your playmates invented, that other people do not know the meaning of? In short, we human beings have a talking instinct; just as birds have a nest-building instinct, and squirrels an instinct for hiding nuts in the ground.

So if we should take a lot of robin’s eggs, hatch them out in an incubator, feed the little birds by hand and never let them see a grown up bird or a nest, there is no doubt that when the proper time came they would sing, build nests, and take care of their young, much as if they had been brought up by their parents in the usual manner. In the same way, if we should take a lot of tiny babies and bring them up where they never heard a word of speech, there is little doubt that when it became time for them to talk, they would invent for themselves a language to talk with. Indeed, some people think that the reason why there are so many different languages in the world, hundreds and hundreds as there are, is because at various times children have been lost, or all the old people of a tribe have died, and the children having no one to teach them their parents’ tongue, have had to make up a new language for themselves.

But no animal could possibly do this. Whether because they lack this strange talking instinct, or because they simply haven’t anything in particular that they want to say, no group of animals has ever invented a language, nor has any single animal ever learned to talk our human speech. A parrot can utter words; a dog can understand them. But somehow no creature except ourselves ever puts the two together, and talks.

I don’t think we ever half realize what an advantage this being able to talk is to us, nor how utterly helpless we should be without it. Suppose for example you are lost in a strange city. You stop the first passerby, and you say “I want to find such and such a street.” “So many blocks up or down,” he answers, “so many to the right or left”; and with one or two more simple questions from time to time, there you are right on your doorstep.

But suppose your dog gets lost. He can not stop the next dog or man he sees and say, “I belong to Mr. So-and-so on Such-and-such Street; tell me how to get home.” All he can do is to look up into some one’s face and whine; and that may mean equally well, “lam lost,” or “I am hungry,” or “I want a drink,” or “The little boy that owns me has gone into that house and I wish he’d hurry up and come out,” or “I don’t like the place where I am living because there is a horrid cat there that scratches me on the nose, and I wish I could go home and live with you instead,” or “I know you have been in a meat market, because I can smell the nice smell of the fresh meat, and I wish I were going to have some for my dinner in place of dog biscuit which I don’t like.”

All these ideas, and forty others like them, the dog would have to express in precisely the same way, and leave to his hearer to guess which one he might happen to mean this particular time. In fact, about all the ideas that a dog can express are, “I want something that I haven’t got,” “I am afraid I’m going to get something I don’t want,” and “If somebody doesn’t look out, there’s going to be a very dickens of a row here in about a minute.” What he may think beyond these simple matters he has pretty much to keep to himself.

And did you ever think how extremely difficult it would be to learn anything, lacking words to learn it with? You can tell the capitals of the United States, or the chief rivers of Asia, or the kings of England, because somebody who knew has told somebody else, and he somebody else, until the information has at length filtered down to you. Whatever you do not know and want to know, you can find out from somebody who does know, either by asking directly or by looking in a book where somebody has written it down. But a dog can find out things only by seeing them for himself, and when he does find them out, he has no way of telling any other dog anything about them.

No wonder that cow I was telling you about a short while ago was not in the least surprised when her calf ripped apart and the hay fell out. Why should she not think that all calves are stuffed with hay, and are expected sooner or later to rip apart and provide hay for their mammas’ supper? She has no way of finding out what calves are made of inside. If you wanted to know, you would ask. She couldn’t.

I suppose a child going to school and asking questions at home and getting them answered, as every child should, learns at least a hundred times as fast as any animal can possibly learn. I suppose too that a dog or cat, living in one place and doing about the same things every day, learns in a year or two all that there is to be known about his particular world, and so finds out nothing more all the rest of his life. You learn for lessons something new every day, you see new people, and visit new places, you have new things to eat, and new clothes. But the animals always have the same clothes, and the same things to eat. Most of them do not travel; if they do sometimes make new friends, the new friends cannot tell them anything. Think, then, how ignorant must be the rabbit shut up in one pen, the cow confined to one pasture, the parrot always in the same cage. They do the same things day after day; in a week they have learned all there is to be known.

Of course, an animal cannot tell time nor count; for telling time and counting require words. He cannot give names to anything, nor remember anything by name, nor think about anything in words. Indeed, it is pretty difficult, without words, to do any thinking at all. We can learn, think, remember, plan, contrive, teach, ask questions, answer them, because we have words to work with. The animals have no words. Therefore, the wisest of them is like a child of four.

XVIII

Something More About Speech and Thinking

We say commonly that we think with our brains. That is true; but it is by no means the whole story. The brain has two halves, just alike, exactly as the body has. In fact, the two sides of the brain are even more precisely alike than the two hands.

Nevertheless, we do all our thinking with one side only. If we are naturally right-handed persons, we do our thinking on the left side of the head. If we are naturally left-handed, we do our thinking on the right side. But we do not use both sides. Each half of the brain governs the muscles of one side of the body; but the thinking is done with one side only.

This very peculiar state of affairs is in some way or other connected with our power of speech. The animals, who cannot use words, do their thinking, so far as we know, equally on both sides of their heads; and we have every reason to believe that if we did not talk, we too should do our thinking with both sides.

Let us see if we cannot in part make out the reason for this arrangement. Let us suppose you are using your mouth and tongue, not to talk with, but to eat your breakfast. Each half of the brain, as I have said, controls the muscles on one side of the body; and as I dare say you have long ago been taught in school, a set of long nerve fibers, like so many telephone lines, connects each muscle with the proper region of the outer surface of the brain. You are, we are supposing, at breakfast, and you take a bite of bread and butter. At once, the two halves of the tongue telephone by way of the nerves, each to its own side of the brain, “Something good to eat, shall we chew and swallow?” Then each half-brain telephones back, “Message received, stand by to chew, on signal; will call up other side.” Then each side of the head rings up the other side and says, “Bread and butter reported in my half the mouth; shall chew at once. Are you ready to start? Go!” And away go the two sides of the face working together.

Now of course I do not mean to say that this is literally what occurs every time you attempt to do anything that requires both sides of the body to act together. Nevertheless, something like this really does happen. You know how a tiny baby cannot even look at the same point with both eyes at once, but sends them straddling off, one looking one way, the other another. It takes some days for the two halves of the baby’s brain to learn to consult one another, and to handle their two eyes in co-operation. So with any act that uses two hands, or two feet, or a hand on one side of the body and a foot on the other. The two halves of the brain have to call across to one another, along certain nerve fibers which run back and forth between the two, in order that the actions of the two sides of the body may keep together. You can easily see that if one side of the brain tried to open its side of the mouth, while the other side was trying to shut its, you would probably have to start for school without your breakfast.

Naturally, after the two brain halves have been living together for a few years, growing up together in the same house, they learn to work almost like one. Still this signaling back and forth does take time. So long as we are merely eating, or walking, or shoveling snow, the process goes on fast enough. But talking is a different matter. When you are talking thirteen to the dozen, just as fast as you can chatter, every several letter of every single word you utter demands at least one change of position of tongue or lips or throat, and generally of them all.

What would happen if the two halves of the brain had to stop to call one another up and say, “Now I am on the point of starting to say ‘t’ with my half of the mouth. Are you ready with yours?” “Now I am going to tuck on an ‘h.’ Are you ready with your side?” “Now go ahead with the ‘e.’ Start.” It wouldn’t do at all. It’s altogether too slow a way to get talking done. So by way of saving time, one side of the brain has taken entire charge of the talking; for this, one side only of the brain runs both sides of the mouth.

When we eat, then, both sides of the brain are in action. But when we use the very same muscles for speaking, then we use one side of the brain only. When we lift a weight with both hands, we signal to the muscles from both halves of the brain. But when we play the piano with both hands, the same side of the brain takes charge of both. I am, for example, using a type-writer, and writing with both hands. Only one half of my brain, however, has charge of the writing. The other half simply side-tracks itself, stands aside, and doesn’t meddle. But the minute I stop writing and start to put my machine in its case, then the other half-brain switches on again, and takes care of its side. If I should hurt my right hand, so that I had to do all my writing with the left, the writing side of my brain would still do all the writing, while the other side that commonly manages my left hand would stand and look on. All these very special, complex, rapid and difficult tasks, like talking, writing, playing the piano, or running the type-writer, are done by one side of the brain. The slow and easy things are done by both.

But the animals, who do not either talk or write or play musical instruments, they use the two sides of their brains alike.

XIX

Why Most Of Us Are Right-Handed

We do our talking with one side of the brain only. But talking is somewhat intimately connected with thinking. We ought to always, we generally do, think before we speak; while much of our thinking, and on the whole the most important part, consists in saying over words to ourselves.

Speech and thinking, then, go so often together, that it becomes a great convenience to get the thinking done also on one side of the head only, and on the same side with the speech. It might have been either side; it did happen to be the left. One cannot say why, any more than why the heart should be on the left side and the liver on the right, or why some snail shells curl one way and some the other. But at any rate it is the left side.

Now I don’t know whether you have yet been taught in your school physiology, if you have not yet you will be shortly, that the nerves which run from the brain to various parts of the body, cross over to the other side from the one on which they start. Thus the right side of the brain controls the left side of the body; while the left side of the brain controls the right side of the body.

But if the thinking is all done on the left side of the head, which hand will act more quickly on the thought? Evidently, the right hand; messages for that hand travel directly along the nerves, crossing sides once. Therefore we are right-handed.

Some people, however, are born with the “speech center,” as it is called, on the right side of the head instead of on the left. For such persons the most direct path is to the left hand. These persons, then, are naturally left-handed. The difference, therefore, between a right-handed and a left-handed person is not so much in the side of the body with which they have learned to act, as in the side of the brain with which they have learned to think. But the animals, who think on both sides alike, also use either forefoot equally well, and are neither right nor left-handed.

This talking on one side of the brain has another curious result. Did you ever stop to think why a right-handed batter stands with his left side to the ball? Or why a driver of a horse sits on the right hand end of the seat? Or why the engineer of a locomotive sits on the right side of the cab, altho this position forces him to use his left hand for the throttle valve? Or why you sight a gun or look thru a spy-glass with the right eye? Or why you draw a bow with the right hand on the string?

It is all on account of this same one-sided speech center. This has made us right-handed; it has also made us right-eyed. We think much in words; but we also think much about how things look. We think most quickly concerning messages which come in on the thinking side of the brain; and those are from the right eye, since the eye nerves, like those from the hand, cross sides on the way. So hand and eye and speech and thought all use the same side of the head; and sight and thought and action follow one another most easily. Being then right-eyed, we stand to bat, or sit to drive, or use gun or bow or telescope, in the way which gives the better sight to the better eye. But of course, naturally left-handed people are also naturally left-eyed.

Some people, however, are as we say, ambidextrous; that is, they use both hands about equally well, just as all animals do. Nobody, however, is ever naturally ambidextrous. Sometimes the ambidexters are people who have hurt the right hand, and had to learn to use the left. More often they are persons naturally left-handed who have been taught to use the right hand more than is natural in an effort to make them right-handed, tho of course they really are just as left-handed at ever, since no use of the other hand will change over the speech center. But some ambidexters, oddly enough, are made so by an injury to the sight of the right eye, if they were right-handed to begin with, or to the left eye if they were left-handed. Hand and eye have so often to work together and work quickly, that one tends to use the hand on the side of the better eye, even when that is the wrong side.

At any rate, tho it is an excellent plan to learn to do all heavy work equally well on either side of the body and with either hand, fine work and quick work and thinking work had better be done with the hand that does it most naturally. This keeps writing, thinking, speaking, memory, and the rest all close together, on one side of the head, handy to one another, instead of scattering them about, some on the wrong side of the body, some on the right.

XX

Where We Do Our Thinking

We think only on the left side of our heads—that is easy to say if we are normal right-handed persons. If for any reason we have got to thinking on the right side, that will, as I have explained, usually result in making us left-handed.

Yet we do not use the whole of even one side of the brain. So far as is known, we do not think at all with the front part of the head. All our speaking and most of our thinking are done from a spot hardly larger than a cart-wheel dollar, which lies on the side of the head just above the left ear. At any rate, an injury to this particular part of our brain puts a sudden stop to our ability to think and speak.

When you put your left elbow on the table and lean your head on your hand, your hand just about covers the only portion of the brain with which you ever do any thinking at all; while only with the part that lies directly under the middle of the palm, and is as I have said, about the size of a silver dollar, do you ordinarily think very much or hard. This thinking part of the brain lies on the outside, and is just about as thick thru as the hand is.

But even this small thinking place in the brain is not all alike. Directly over the ear, a place that you can almost cover with your thumb, lies the most important part of all, the place where we remember and handle words. At the bottom of this word spot, we remember how words sound. An inch farther up and toward the back, we remember how words look in print. A little farther up and forward lies the “speech center,” from which, when we want to talk, we direct the tongue and lips what to say. Thus we get our word-hearing, our word-seeing, and our word-speaking centers close together, so that when we speak we have close by and handy our memory of what we have heard in words, and of what we have read.