[V. HOW TO MEMORIZE]
There is no sharp distinction between habit and memory. Both are governed by the general laws of association. They shade off into each other, and what one might call habit another with equal reason might call memory. Their likenesses are greater than their differences. However, there is some reason for treating the topic of association under these two heads. The term memory has been used by different writers to mean at least four different types of association. It has been used to refer to the presence of mental images; to refer to the consciousness of a feeling or event as belonging to one's own past experience; to refer to the presence of connections between situation and motor response; and to refer to the ability to recall the appropriate response to a particular situation. The last meaning of the term is the one which will be used here. The mere flow of imagery is not memory, and it matters little whether the appropriate response be accompanied by the time element and the personal element or not. In fact, most of the remembering which is done in daily life lacks these two elements.
Memory then is the recall of the appropriate response in a given situation. It differs from habit in that the responses referred to are more often mental rather than motor; in that it is less automatic, more purposeful. The fact that the elements involved are so largely mental makes it true that the given fact is usually found to have several connections and the given situation to be connected with many facts. Which particular one will be "appropriate" will depend on all sorts of subtle factors, hence the need of the control of the connection aeries by a purpose and the diminishing of the element of automaticity. As was said before, there is no hard and fast line of division between habit and memory. The recall of the "sqrt(64)" or of how to spell "home" or of the French for "table" might be called either or both. All that was said in the discussion of habit applies to memory.
This ability to recall appropriate facts in given situations is dependent primarily on three factors: power of retention, number of associations, organization of associations. The first factor, power of retention, is the most fundamental and to some extent limits the usefulness of the other two. It is determined by the character of the neurones and varies with different brains. Neurones which are easily impressed and retain their impression simply because they are so made are the gift of nature and the corner stone of a good memory. This retention power is but little, if at all, affected by practice. It is a primary quality of the nervous system, present or absent to the degree determined by each individual's original nature. Hence memory as a whole cannot be unproved, although the absence of certain conditions may mean that it is not being used up to its maximum capacity. Change in these conditions, then, will enable a person to make use of all the native retentiveness his nervous system has. One of the most important of these conditions is good health. To the extent that good blood, sleep, exercise, etc., put the nervous system in better tone, to that extent the retentive power present is put in better working order. Every one knows how lack of sleep and illness is often accompanied by loss in memory. Repetition, attention, interest, vividness of impression, all appeal primarily to this so-called "brute memory," or retentive power. Pleasurable results seem not to be quite so important, and repetition to be more so when the connections are between mental states instead of between mental states and motor responses. An emphasis on, or an improvement in, the use of any one of these factors may call into play to a greater extent than before the native retentive power of a given child.
The power to recall a fact or an event depends not only upon this quality of retentiveness, but also upon the number of other facts or events connected with it. Each one of these connections serves as an avenue of approach, a clew by means of which the recall may operate. Any single blockade therefore may not hinder the recall, provided there are many associates. This is true, no matter how strong the retentive power may be. It is doubly important if the retentive power is weak. Suppose a given fact to be held rather weakly because of comparatively poor retentive power, then the operation of one chain of associates may not be energetic enough to recall it. But if this same fact may be approached from several different angles by means of several chains of associations, the combined power of the activity in the several neurone chains will likely be enough to lift it above the threshold of recall. Other things being equal, the likelihood that a needed fact will be recalled is in proportion to the number of its associations.
The third factor upon which goodness in memory depends is the organization of associates. Number of connections is an aid to memory--but systematization among these connections is an added help. Logical arrangement of facts in memory, classification according to various principles, orderly grouping of things that belong together, make the operation of memory more efficient and economical. The difference between mere number of associations and orderly arrangement of those associations may be illustrated by the difference in efficiency between the housekeeper who starts more or less blindly to look all over the house for a lost article, and the one who at least knows that it must be in a certain room and probably in a certain bureau drawer. Although memory as a whole cannot be improved because of the limiting power of native retentiveness, memory for any fact or in any definite field may be improved by emphasizing these two factors: number of associations and organization among associations.
Although all three factors are operative in securing the best type of memory, still the efficiency of a given memory may be due more to the unusual power of one of them than to the combined effect of the three. It is this difference in the functioning of these three factors which is primarily responsible for certain types of memory which will be discussed later. It must also be borne in mind that the power of these factors to operate in determining recall varies somewhat with age. Little children and old people are more dependent upon mere retentiveness than upon either of the others, the former because of lack of experience and lack of habits of thought, the latter because of the loss of both of these factors. The adult depends more on the organization of his material, while in the years between the number of the clews is probably the controlling factor. Here again there is no sharp line of division; all three are needed. So in the primary grades we begin to require children to organize, and as adults we do all we can to make the power of retention operate at its maximum.
Many methods of memorizing have been used by both children and adults. Recently experimental psychology has been testing some of them. So far as the learner is concerned, he may use repetition, or concentration, or recall as a primary method. Repetition means simply the going over and over again the material to be learned--the element depended upon being the number of times the connection is made. Concentration means going over the material with attention. Not the number of connections is important, but the intensity of those connections. In recall the emphasis is laid upon reinstating the desired connections from within. In using this method, for instance, the learner goes over the material as many times as he sees necessary, then closes the book and recalls from memory what he can of it.
The last of the three methods is by far the best, whether the memory desired be rote or logical, for several reasons. In the first place it involves both the other methods or goes beyond them. Second, it is economical, for the learner knows when he knows the lesson. Third, it is sure, for it establishes connections as they will be used--in other words, the learning provides for recall, which is the thing desired, whereas the other two methods establish only connections of impression. Fourth, it tends to establish habits that are of themselves worth while, such as assuming responsibility for getting results, testing one's own power and others. Fifth, it encourages the use of the two factors upon which memory depends, which are most capable of development, i.e., number and organization of associations.