Fundamental Law of Association.—Stated on the physiological side, the law of habit as set forth in the definition of association in the preceding section includes all the laws of association. In different phrasing we may say: (1) Neurone groups accustomed to acting together have the tendency to work in unison. (2) The more frequently such groups act together the stronger will be the tendency for one to throw the other into action. Also, (3) the more intense the excitement or tension under which they act together the stronger will be the tendency for activity in one to bring about activity in the other.

The corresponding facts may be expressed in psychological terms as follows: (1) Facts accustomed to being associated together in the mind have a tendency to reappear together. (2) The more frequently these facts appear together the stronger the tendency for the presence of one to insure the presence of the other. (3) The greater the tension, excitement or concentration when these facts appear in conjunction with each other, the more certain the presence of one is to cause the presence of the other.

Several different types of association have been differentiated by psychologists from Aristotle down. It is to be kept in mind, however, that all association types go back to the elementary law of habit-connections among the neurones for their explanation.

Association by Contiguity.—The recurrence in our minds of many of the elements from our past experience is due to the fact that at some time, possibly at many times, the recurring facts were contiguous in consciousness with some other element or fact which happens now to be again present. All have had the experience of meeting some person whom we had not seen for several months or years, and having a whole series of supposedly forgotten incidents or events connected with our former associations flood into the mind. Things we did, topics we discussed, trips we took, games we played, now recur at the renewal of our acquaintance. For these are the things that were contiguous in our consciousness with our sense of the personality and appearance of our friend. And who has not in similar fashion had a whiff of perfume or the strains of a song recall to him his childhood days! Contiguity is again the explanation.

At the Mercy of Our Associations.—Through the law thus operating we are in a sense at the mercy of our associations, which may be bad as well as good. We may form certain lines of interest to guide our thought, and attention may in some degree direct it, but one's mental make-up is, after all, largely dependent on the character of his associations. Evil thoughts, evil memories, evil imaginations—these all come about through the association of unworthy or impure images along with the good in our stream of thought. We may try to forget the base deed and banish it forever from our thinking, but lo! in an unguarded moment the nerve current shoots into the old path, and the impure thought flashes into the mind, unsought and unwelcomed. Every young man who thinks he must indulge in a little sowing of wild oats before he settles down to a correct life, and so deals in unworthy thoughts and deeds, is putting a mortgage on his future; for he will find the inexorable machinery of his nervous system grinding the hated images of such things back into his mind as surely as the mill returns to the sack of the miller what he feeds into the hopper. He may refuse to harbor these thoughts, but he can no more hinder their seeking admission to his mind than he can prevent the tramp from knocking at his door. He may drive such images from his mind the moment they are discovered, and indeed is guilty if he does not; but not taking offense at this rebuff, the unwelcome thought again seeks admission.

The only protection against the return of the undesirable associations is to choose lines of thought as little related to them as possible. But even then, do the best we may, an occasional "connection" will be set up, we know not how, and the unwelcome image stands staring us in the face, as the corpse of Eugene Aram's victim confronted him at every turn, though he thought it safely buried. A minister of my acquaintance tells me that in the holiest moments of his most exalted thought, images rise in his mind which he loathes, and from which he recoils in horror. Not only does he drive them away at once, but he seeks to lock and bar the door against them by firmly resolving that he will never think of them again. But alas! that is beyond his control. The tares have been sown among the wheat, and will persist along with it until the end. In his boyhood these images were given into the keeping of his brain cells, and they are only being faithful to their trust.

Association by Similarity and Contrast.—All are familiar with the fact that like tends to suggest like. One friend reminds us of another friend when he manifests similar traits of character, shows the same tricks of manner, or has the same peculiarities of speech or gesture. The telling of a ghost or burglar story in a company will at once suggest a similar story to every person of the group, and before we know it the conversation has settled down to ghosts or burglars. One boastful boy is enough to start the gang to recounting their real or imaginary exploits. Good and beautiful thoughts tend to call up other good and beautiful thoughts, while evil thoughts are likely to produce after their own kind; like produces like.

Another form of relationship is, however, quite as common as similars in our thinking. In certain directions we naturally think in opposites. Black suggests white, good suggests bad, fat suggests lean, wealth suggests poverty, happiness suggests sorrow, and so on.

The tendency of our thought thus to group in similars and opposites is clear when we go back to the fundamental law of association. The fact is that we more frequently assemble our thoughts in these ways than in haphazard relations. We habitually group similars together, or compare opposites in our thinking; hence these are the terms between which associative bonds are formed.

Partial, or Selective, Association.—The past is never wholly reinstated in present consciousness. Many elements, because they had formed fewer associations, or because they find some obstacle to recall, are permanently dropped out and forgotten. In other words, association is always selective, favoring now this item of experience, now that, above the rest.

It is well that this is so; for to be unable to escape from the great mass of minutiæ and unimportant detail in one's past would be intolerable, and would so cumber the mind with useless rubbish as to destroy its usefulness. We have surely all had some experience with the type of persons whose associations are so complete and impartial that all their conversation teems with unessential and irrelevant details. They cannot recount the simplest incident in its essential points but, slaves to literalness, make themselves insufferable bores by entering upon every lane and by-path of circumstance that leads nowhere and matters not the least in their story. Dickens, Thackeray, George Eliot, Shakespeare, and many other writers have seized upon such characters and made use of them for their comic effect. James, in illustrating this mental type, has quoted the following from Miss Austen's "Emma":

"'But where could you hear it?' cried Miss Bates. 'Where could you possibly hear it, Mr. Knightley? For it is not five minutes since I received Mrs. Cole's note—no, it cannot be more than five—or at least ten—for I had got my bonnet and spencer on, just ready to come out—I was only gone down to speak to Patty again about the pork—Jane was standing in the passage—were not you, Jane?—for my mother was so afraid that we had not any salting-pan large enough. So I said I would go down and see, and Jane said: "Shall I go down instead? for I think you have a little cold, and Patty has been washing the kitchen." "Oh, my dear," said I—well, and just then came the note.'"

The Remedy.—The remedy for such wearisome and fruitless methods of association is, as a matter of theory, simple and easy. It is to emphasize, intensify, and dwell upon the significant and essential in our thinking. The person who listens to a story, who studies a lesson, or who is a participant in any event must apply a sense of value, recognizing and fixing the important and relegating the trivial and unimportant to their proper level. Not to train one's self to think in this discriminating way is much like learning to play a piano by striking each key with equal force!

3. TRAINING IN ASSOCIATION

Since association is at bottom nothing but habit at work in the mental processes, it follows that it, like other forms of habit, can be encouraged or suppressed by training. Certainly, no part of one's education is of greater importance than the character of his associations. For upon these will largely depend not alone the content of his mental stream, the stuff of his thinking, but also its organization, or the use made of the thought material at hand. In fact, the whole science of education rests on the laws and principles involved in setting up right systems of associative connections in the individual.

The Pleasure-Pain Motive in Association.—A general law seems to obtain throughout the animal world that associative responses accompanied by pleasure tend to persist and grow stronger, while those accompanied by pain tend to weaken and fall away. The little child of two years may not understand the gravity of the offense in tearing the leaves out of books, but if its hands are sharply spatted whenever they tear a book, the association between the sight of books and tearing them will soon cease. In fact, all punishment should have for its object the use of pain in the breaking of associative bonds between certain situations and wrong responses to them.

On the other hand, the dog that is being trained to perform his tricks is rewarded with a tidbit or a pat when the right response has been made. In this way the bond for this particular act is strengthened through the use of pleasure. All matter studied and learned under the stimulus of good feeling, enthusiasm, or a pleasurable sense of victory and achievement not only tends to set up more permanent and valuable associations than if learned under opposite conditions, but it also exerts a stronger appeal to our interest and appreciation.

The influence of mental attitude on the matter we study raises a question as to the wisdom of assigning the committing of poetry, or Bible verses, or the reading of so many pages of a literary masterpiece as a punishment for some offense. How many of us have carried away associations of dislike and bitterness toward some gem of verse or prose or Scripture because of having our learning of it linked up with the thought of an imposed task set as penance for wrong-doing! One person tells me that to this day she hates the sight of Tennyson because this was the volume from which she was assigned many pages to commit in atonement for her youthful delinquencies.

Interest as a Basis for Association.—Associations established under the stimulus of strong interest are relatively broad and permanent, while those formed with interest flagging are more narrow and of doubtful permanence. This statement is, of course, but a particular application of the law of attention. Interest brings the whole self into action. Under its urging the mind is active and alert. The new facts learned are completely registered, and are assimilated to other facts to which they are related. Many associative connections are formed, hence the new matter is more certain of recall, and possesses more significance and meaning.

Association and Methods of Learning.—The number and quality of our associations depends in no small degree on our methods of learning. We may be satisfied merely to impress what we learn on our memory, committing it uncritically as so many facts to be stored away as a part of our education. We may go a step beyond this and grasp the simplest and most obvious meanings, but not seek for the deeper and more fundamental relations. We may learn separate sections or divisions of a subject, accepting each as a more or less complete unit, without connecting these sections and divisions into a logical whole.

But all such methods are a mistake. They do not provide for the associative bonds between the various facts or groups of facts in our knowledge, without which our facts are in danger of becoming but so much lumber in the mind. Meanings, relations, definitely recognized associations, should attach to all that we learn. Better far a smaller amount of usable knowledge than any quantity of unorganized and undigested information, even if the latter sometimes allows us to pass examinations and receive honor grades. In short, real mastery demands that we think, that is relate and associate, instead of merely absorbing as we learn.

4. PROBLEMS IN OBSERVATION AND INTROSPECTION

1. Test the uncontrolled associations of a group of pupils by pronouncing to the class some word, as blue, and having the members write down 20 words in succession as rapidly as they can, taking in each instance the first word that occurs to them. The difference in the scope, or range, of associations, can easily be studied by applying this test to, say, a fourth grade and an eighth grade and then comparing results.

2. Have you ever been puzzled by the appearance in your mind of some fact or incident not thought of before for years? Were you able to trace out the associative connection that caused the fact to appear? Why are we sometimes unable to recall, when we need them, facts that we perfectly well know?

3. You have observed that it is possible to be able to spell certain words when they occur in a spelling lesson, but to miss them when employing them in composition. It is possible to learn a conjugation or a declension in tabular form, and then not be able to use the correct forms of words in speech or writing. Relate these facts to the laws of association, and recommend a method of instruction that will remove the discrepancy.

4. To test the quickness of association in a class of children, copy the following words clearly in a vertical column on a chart; have your class all ready at a given signal; then display the chart before them for sixty seconds, asking them to write down on paper the exact opposite of as many words as possible in one minute. Be sure that all know just what they are expected to do.

Bad, inside, slow, short, little, soft, black, dark, sad, true, dislike, poor, well, sorry, thick, full, peace, few, below, enemy.

Count the number of correct opposites got by each pupil.

5. Can you think of garrulous persons among your acquaintance the explanation of whose tiresomeness is that their association is of the complete instead of the selective type? Watch for such illustrations in conversation and in literature (e.g., Juliet's nurse).

6. Observe children in the schoolroom for good and poor training in association. Have you ever had anything that you otherwise presumably would enjoy rendered distasteful because of unpleasant associations? Pass your own methods of learning in review, and also inquire into the methods used by children in study, to determine whether they are resulting in the best possible use of association.

CHAPTER XI

MEMORY

Every hour of our lives we call upon memory to supply us with some fact or detail from out our past. Let memory wholly fail us, and we find ourselves helpless and out of joint in a world we fail to understand. A poor memory handicaps one in the pursuit of education, hampers him in business or professional success, and puts him at a disadvantage in every relation of life. On the other hand, a good memory is an asset on which the owner realizes anew each succeeding day.

1. THE NATURE OF MEMORY

Now that you come to think of it, you can recall perfectly well that Columbus discovered America in 1492; that your house is painted white; that it rained a week ago today. But where were these once-known facts, now remembered so easily, while they were out of your mind? Where did they stay while you were not thinking of them? The common answer is, "Stored away in my memory." Yet no one believes that the memory is a warehouse of facts which we pack away there when we for a time have no use for them, as we store away our old furniture.

What is Retained.—The truth is that the simple question I asked you is by no means an easy one, and I will answer it myself by asking you an easier one: As we sit with the sunlight streaming into our room, where is the darkness which filled it last night? And where will all this light be at midnight tonight? Answer these questions, and the ones I asked about your remembered facts will be answered. While it is true that, regardless of the conditions in our little room, darkness still exists wherever there is no light, and light still exists wherever there is no darkness, yet for this particular room there is no darkness when the sun shines in, and there is no light when the room is filled with darkness. So in the case of a remembered fact. Although the fact that Columbus discovered America some four hundred years ago, that your house is of a white color, that it rained a week ago today, exists as a fact regardless of whether your minds think of these things at all, yet the truth remains as before: for the particular mind which remembers these things, the facts did not exist while they were out of the mind.

It is not the remembered fact which is retained, but the power to reproduce the fact when we require it.

The Physical Basis of Memory.—The power to reproduce a once-known fact depends ultimately on the brain. This is not hard to understand if we go back a little and consider that brain activity was concerned in every perception we have ever had, and in every fact we have ever known. Indeed, it was through a certain neural activity of the cortex that you were able originally to know that Columbus discovered America, that your house is white, and that it rained on a day in the past. Without this cortical activity, these facts would have existed just as truly, but you would never have known them. Without this neural activity in the brain there is no consciousness, and to it we must look for the recurrence in consciousness of remembered facts, as well as for those which appear for the first time.

How We Remember.—Now, if we are to have a once-known fact repeated in consciousness, or in other words remembered, what we must do on the physiological side is to provide for a repetition of the neural activity which was at first responsible for the fact's appearing in consciousness. The mental accompaniment of the repeated activity is the memory. Thus, as memory is the approximate repetition of once-experienced mental states or facts, together with the recognition of their belonging to our past, so it is accomplished by an approximate repetition of the once-performed neural process in the cortex which originally accompanied these states or facts.

The part played by the brain in memory makes it easy to understand why we find it so impossible to memorize or to recall when the brain is fatigued from long hours of work or lack of sleep. It also explains the derangement in memory that often comes from an injury to the brain, or from the toxins of alcohol, drugs or disease.

Dependence of Memory on Brain Quality.—Differences in memory ability, while depending in part on the training memory receives, rest ultimately on the memory-quality of the brain. James tells us that four distinct types of brains may be distinguished, and he describes them as follows:

Brains that are:

(1) Like marble to receive and like marble to retain.

(2) Like wax to receive and like wax to retain.

(3) Like marble to receive and like wax to retain.

(4) Like wax to receive and like marble to retain.

The first type gives us those who memorize slowly and with much heroic effort, but who keep well what they have committed. The second type represents the ones who learn in a flash, who can cram up a lesson in a few minutes, but who forget as easily and as quickly as they learn. The third type characterizes the unfortunates who must labor hard and long for what they memorize, only to see it quickly slipping from their grasp. The fourth type is a rare boon to its possessor, enabling him easily to stock his memory with valuable material, which is readily available to him upon demand.

The particular type of brain we possess is given us through heredity, and we can do little or nothing to change the type. Whatever our type of brain, however, we can do much to improve our memory by obeying the laws upon which all good memory depends.