1. Length of the Series and Time of Learning. — One of the first things that Ebbinghaus brought out was the fact that it takes a disproportionate amount of time to learn a long series as contrasted with a short series, for example, he found that with one reading, a series of 7 or 8 syllables could be learned. The table given below brings out the greater amount of work required as the number of syllables in the series is increased.
Number of repetitions Number of syllables necessary for first in a series errorless production Since Ebbinghaus 's investigation was completed a large amount of such work has been done, but in general his conclusions have been many times verified.
2. Acquisition of Sense Material. — The same author learned stanzas of Byron's Don Juan. Each stanza required scarcely 8 repetitions in order to enable the learner, to recite it correctly. Each of the stanzas contained 80 syllables. Each syllable, how- ever, consisted on the average of less than 3 letters. If we con- trast the number of presentations required to learn 80 syllables, the syllables being grouped into ordinary words, with the number of presentations required to learn 80 nonsense syllables, it will be found that the sense material requires relatively few. Ebbing- haus estimated that if a series of 36 nonsense syllables requires 55 repetitions for learning, 80-90 syllables would require at least 80 repetitions; since the sense material required only about 9 repetitions it follows that the learning of sense material requires only about 1/10 as much practice as nonsense material.
22 338 PSYCHOLOGY I 3. Effect of Changing the Order of the Syllables in a Non- sense Series. — The nonsense material gives us an interesting opportunity of testing some of the fundamental facts about human learning. When any given succession of events or objects is presented serially the parts are learned in the order given. We have discussed this problem to a certain extent already under the heading of the determiners of act (page 298) and we found there that frequency was a most potent factor in determining which act will next be performed. In other words, if acts have been learned in the order A, B, C, D, E, F, and the individual is now performing act E, other things being equal, it is safe to predict that act F will follow next because it has most frequently followed E. The question is whether E is the sole determiner of F. The answer has been conclusively returned from the study of nonsense material. Not only is E a determiner of F, but like- wise also in varying measure D, C, B, A. To test this Ebbinghaus learned on any given day several series of nonsense syllables and then made up from this once-learned material several new series. One of the new series was made by skipping one syllable, another by skipping two syllables and so until six syllables were skipped.
The following scheme will make this clear. Let the various series once learned be represented by Roman figures and the posi- tions of the various members of this series by the Arabic numerals as follows: The "skipping-one" series would then be made up as follows: The other series, of course, can be made up in the same way by skipping two syllables, three, and so on. If the syllables are learned merely in the order in which they are presented and the determiner of each succeeding act is solely the act which has just preceded, then the series made by skipping series ought to be as difficult to learn as the originals. Such is by no means the case. All of the "skip" series are learned more readily than the EXPLICIT AND IMPLICIT LANGUAGE HABITS 339 mean of the six originals from which they were composed. The following table presents the results: Re-learning in original order — After 24 hours. 33.3 per cent, saved Re-learning of skip 1 10.8 per cent, saved Re-learning of skip 2 7 per cent, saved Re-learning of skip 3 • 5.8 per cent, saved Re-learning of skip 7 3.3 per cent, saved If a count is kept of the average number of seconds required for learning the original six series, and then for re-learning each of the various derived series, the saving is as follows: The average for the original learning (6 series) was 1266 seconds; skipping 1, the saving was 110 seconds; skipping 2, 79 seconds; skipping 3, 64 seconds; skipping 6, 40 seconds. Where the series are jumbled together (permutation) there is< no saving in time of re-learning. We thus see in learning series of nonsense syl- lables that every syllable is tied up in a forward direction with every other one. In a similar way it has been shown that they are tied up in a backward direction as well.
The Acquisition of More Complex Material. — Several studies have been made upon material which brings about organ- ization or reorganization of the implicit processes such as the learning of a new language or telegraphy. No experimental studies have been made on learning to compose music. The learner who studied Russian in an experimental way (Swift) had had no previous training in that language. The study began March 30, 1905, and ended June 14 of the same year. It con- sisted of 30 minutes' study followed immediately by a 15 minutes' test of reading ability. The daily study of 30 minutes was car- ried on in the ordinary way, the time being divided among the vocabulary, conjugations and declensions.. No effort was made to work under any great strain. The score was made on the basis of the number of words read during the daily 15 minutes' test, The learning curve (not shown) shows the same factors at work as in the acquisition of manual skill — a rather rapid rise at first.
340 PSYCHOLOGY 340 PSYCHOLOGY a severe slip back, then another rapid rise, another severe slip back, then a slower gradual rise with marked fluctuations. The rate of progress even at the beginning was much slower than learning to typewrite. The curve as a whole shows a surprising number of plateaux, at least four well-marked ones appearing, but the lack of material in the day's lesson and the unsatisfactory way in which such scores can be obtained probably keep the curve from being a true picture of such acquisitions. The average score on the first two days was about 20 words read per 15 minutes; the average score on the 65th day was approximately 65. Bryan and Harter have given a somewhat better controlled study in learning to receive telegraphic messages. The curve of receiv- ing rises quite slowly, very much more slowly and irregularly than does the curve for sending messages, since sending is a much less complex habit to form. Furthermore, the curve is marked by several plateaux, each plateau being followed by a period of more or less marked improvement.
Improvement in Subvocal Arithmetic. — It is very difficult, of course, to find examples in the experimental literature of acqui- sition or improvement in pure implicit laryngeal work. Possibly the best examples of such work and of the types of improvement that occur are found in the working of arithmetic problems with- out exteroceptive aids. Starch worked with eight subjects and had them multiply a three-place by a one-place number — 50 examples per day for 14 days. A table follows (quoted from Thorndike): Examples done per Examples done per 10 minutes on 1st 10 minutes on 14th Gross Percentile Individual day day gain gain It will be seen that the improvement was quite marked, that the small amount of practice done on each day for 14 days enabled EXPLICIT AND IMPLICIT LANGUAGE HABITS 341 the subjects to do nearly twice as many examples on the average as they could do at the beginning of practice. This example, of course, must be looked upon as improvement in a given func- tion and not as the acquisition of a totally new habit. The sub- jects were adults and hence already possessed a respectable measure of ability in this function. Several other individuals have studied improvement in subvocal arithmetic. In general the results are similar to those obtained by Starch.
It would be extremely instructive to obtain data on the acqui- sition and improvement in laryngeal organization of other types. For example, we know nothing in a statistical way concerning improvement of ability in subvocal reading or of such total activ- ities as constructing a lecture, organizing a book or planning an invention.
"Transfer" of Practice From One Language Function to Another. — We gave, on page 289, a short statement of the ' ' trans- fer " of training both in the realm of manual activity and in laryngeal. It seems well to note here again that there is a slight transfer in most cases, but in general this can be accounted for on the basis of the identical elements or identical part processes involved in the two activities under observation.
Summary of Experimental Studies in Laryngeal Learn- ing.— The formation of laryngeal habits is a subject which has been very inadequately studied in psychology largely because of the difficulties involved in getting a measure of improvement and in general in controlling the results. Very many functions which combine laryngeal with manual activity have been studied very carefully in the laboratory, such as the improvement in mark- ing given letters on a page of ordinary print, putting English prose into German script, writing prose in code, and the like. On page 305 we have already considered certain of these habits, such as typewriting.
In general, it may be said that the acquisition of laryngeal habits is similar in most respects to the learning of manual acts. Laryngeal activity1 has not been studied with sufficient thorough- ness for us to give it any detailed discussion.
342 PSYCHOLOGY 342 PSYCHOLOGY D. RETENTION OR MEMORY OF LARYNGEAL HABITS. Effect of No Practice on Laryngeal Habits. — Ebbinghaus and others have tested quite extensively the effect of disuse (for- getting) upon nonsense syllables. One of the things which ap- peared earliest was the fact that after a series of nonsense syllables had been learned to the point of one errorless1 reproduc- tion and then put away, it could not be repeated twenty minutes later. The most interesting thing appearing was the fact that any such disused series could be re-learned much more rapidly than originally. Hence it became possible to adopt the following method: To learn a large number of nonsense syllables, say 8 series of 13 syllables each, and then re-learn one at the end of 20 minutes, another after an hour, another after one day and so on. A numerical measure of the saving can be obtained by subtracting the number of repetitions required for re-learning from the number of repetitions required in the original learning. The following table from Ebbinghaus gives in percentage the amount of time saved in re-learning the nonsense syllables after varying intervals: Length of period of disuse Gain in per cent.
In other words, this table shows that the loss is very rapid at first and very slow thereafter. After the interval of an hour, more than half the original work has to be done before the series can be repeated without error. After 8 hours almost % of the original work is necessary. After 24 hours the rate of deteriora- tion is very slow indeed. The table is shown graphically in Fig. 64. These experiments have been repeated by Radossawljewitsch, by Bean and by students of nearly every laboratory. In general, Ebbinghaus 's work has been confirmed with the possible exception that the loss is less severe at the start than he shows it to be. All EXPLICIT AND IMPLICIT LANGUAGE HABITS 343 investigators agree that the loss is at first extremely rapid. If this rapid deterioration in a language function is contrasted with the hardly perceptible loss in typewriting (page 305) after long periods of no practice the difference in the two types of function, so far as deterioration in the non-practice period is concerned, appears with startling clearness. The curve given below shows the loss during the first 24 hours.
Retentioh of Sense Material. — Radossawljewitsch and also Magneff studied the effect of disuse on sense material (poetry) learned to the point of two perfect reproductions and then re- learned after a certain interval. The loss after disuse for vary- ing intervals was determined as for nonsense syllables in the above test of Ebbinghaus. The following table presents part of the results: Length of period of disuse Gain in per cent.
19 minutes 58.2 It will be seen that the loss is not so rapid at first as in the case of nonsense syllables, but that the loss at the end of thirty days is approximately the same.
It is unfortunate that there are no good studies of this type of forgetting. Radossawljewitsch 's work shows so much varia- tion as likewise does Magneff 's that too great dependence cannot be placed in them. In apparent contradiction to this rapid for- getting of sense material stand the cases where poems learned in early childhood can be repeated after years of disuse; sim- ilarly parts of chapters from the Bible learned in youth, and con- versations heard in childhood can be repeated in old age. But these were originally overlearned and in youth were many times taken up and re-learned. Such examples are in no sense a con- tradiction of the work which has been done in the laboratory.
Effect of Overlearning. — In the above work the series of 40 30 20 10 16 24 31 FIG. 64. — The curve of forgetting for nonsense syllables. Data from Ebbinghaus. The vertical line shows the percentage of time saved in relearning; the horizontal, the interval in days between learning and re-learning. The curve shows in a striking way the tremendous loss which the first day entails.
EXPLICIT AND IMPLICIT LANGUAGE HABITS 345 nonsense syllables was just barely learned. The question arises next as to what the effect would be in time saved in re-learning if, instead of stopping learning at this point, we continued it, for some time. Ebbinghaus found that the effect of reading a series over more often than was necessary to be able to just repeat it was not lost. If it is presented three times more to-day than is required for a first errorless repetition, one presentation will be saved in the re-learning twenty-four hours afterwards; if read six times more than necessary to-day, two repetitions will be saved in re-learning after a similar lapse of time. This saving does not continue in the same ratio when the number of presentations given in learning is increased beyond sixty-four.
Can Memory be Improved? — In order to answer this ques- tion it seems necessary to point out that when it is asked, memory is used in a sense somewhat different from that employed in the present text. Memory in this enlarged sense refers really to the whole process of learning and re-learning. Of course, even in the formation of a habit by daily practice retention of what was learned the day before must occur or progress is blocked. The question really at issue can be put concretely: Given homo- geneous but different material, for example, several thousand lines of prose to learn verbatim, and assume that I have had some practice in committing (learning) such material, will I be able to learn the last hundred lines any more rapidly than the first hundred lines? Or again, assuming that all ten syllable series of nonsense material are of equal difficulty, will the learning of a thousand series decrease materially the length of time it takes me to commit such material? From the standpoint of acquisition it seems to be true that there is a certain coefficient of commit- ment for each individual which for that individual remains almost permanent. Undoubtedly there is some slight improvement, but Ebbinghaus, after working some three or four years with nonsense material, found no very great improvement.
The question also refers to the amount of loss after a period of no practice. All of the experiments seem to show, assuming that the material was learned in an associated and connected way in the first place, that there is no way to stop the loss except by 346 PSYCHOLOGY greatly overlearning. There are a great many mnemonic devices and special association schemes for ' ' improving ' ' memory. Many of them are exceedingly ingenious and "guaranteed to improve one 's memory one hundred per cent, in thirty days. ' ' There is nothing new in any of these schemes and they certainly do not ''improve the memory" in the sense that psychologists would use the term improvement.
Of prodigies in memory little can be said. That there are enormous individual variations in the ability of different people to carry around with them isolated dates, numbers, whole pages of scientific material, is well known by every one. Little fur- ther can be said on the topic. They belong in the same class with the other types of prodigies, for example, the infant mathemat- ical wonder and the child musician and composer.
Concluding Statements. — It would be instructive to take up the study of language in some of its broader aspects; in par- ticular the following points would be of special interest to psy- chologists: (1) The acquisition of language in blind deaf-mutes. (2) The symbolic and folk-lore side of our own and other lan- guages. (3) Stuttering, stammering and allied defects. (4) The effect of central nervous system lesions upon language mechanisms, as is seen in aphasia and in agraphia. (5) The speech of psychopathic individuals, especially the phenomena seen in the flights of the manic, the disintegration of speech in paretics and the organized language systems of the paranoiac types. (6) The slang and profane words and their connection with emotional states. (7) The language systems in day and night dreaming. Most of these topics are so broad that even a central viewpoint cannot be given without devoting a special chapter to each.
We have attempted in the present chapter merely to trace the similarity in the development and use of explicit and implicit language activities to the development and use of other forms of bodily integration. Language is an intimate and necessary part of the individual's adjustments. While we have singled out language functions for special study, it must be recalled that several times we have mentioned the artificiality of this pro- EXPLICIT AND IMPLICIT LANGUAGE HABITS 347 cedure. The normal human organism functions as a whole al- ways. Through training it becomes organized in all of its parts to make a certain adjustment or perform a certain act, be that act the driving of a nail, flying across the Atlantic Ocean or multiplying silently one four-place number by another four- place number. Each of these complex functions has as its con- stituent parts emotional, instinctive, and explicit and implicit habit factors. The parts are all tied together and work together when the individual is performing that function. Our illustra- tion in the previous chapter of the behavior of the motor-boat owner in trying to make his engine run properly shows the closely interlocking, integrated activity of the hands, arms and legs, involving also instinctive emotional factors and finally language activity; it is typical of all adjustments.
The present chapter finishes our study of the genesis and func- tioning of part reactions. In it we have tried to present the data which will enable the student to put the organism back together again and view him as an, integrated, biological going concern. This completely integrated organism is a personality or indi- vidual. The following chapter takes up the individual at work upon one or another problem.
CHAPTER X THE ORGANISM AT WORK A. THE FUNCTIONING OF ESTABLISHED HABIT SYSTEMS.
What is Meant by Function. — Several times in the text we have had occasion to speak of functions. Now that we have ex- amined most of the phases of an individual 's acquisitions both of the explicit and implicit kinds it seems well to get a more exact formulation of what is meant by the term. After an act has been acquired and used for a definite time and is then repeatedly put away and again used, the learning and re-learning phases and periods of no practice become of little consequence. We assume that every normal individual can perform the acts re- quired by a social environment and we do not care particularly whether it took him a long time to learn them or a short time. We are interested, in the discussion which follows, in the question as to the rapidity and accuracy with which those habits work and the factors which influence them. It is convenient to call each organized habit system of an individual which is always ready to act under appropriate stimulation, an acquired function, in contrast to emotional and instinctive functions. (The total assets of an individual are the sum of his hereditary and acquired functions, his retentiveness and his plasticity. Examples of such acquired functions are, of course, talking, walking, swimming, addition, subtraction, writing and all similar ones discussed in the preceding two chapters. As we use the term, it has no fixed implication and is not a mathematical or even a rigidly scientific one. A function is really, then, a phase of activity that one happens to be studying and measuring; the acquired func- tions are equivalent really to habits except for the fact that when we use the term function we generally (but not even here always) leave the genetic aspect out of consideration. New habits, if continued, end always by giving us new functions. In studying children (or adults if learning) the term habit is emphasized; in studying adults the term function is most frequently met with, THE ORGANISM AT WORK 349 since in the adult the learning and re-learning aspects are not of importance unless we wish to get some index of an individual's plasticity. This distinction between the genetic or acquisition phase of any activity and its later exercise has led to some con- fusion in psychology.
The efficiency of these organized functional systems never changes very much in the adult. They are not practiced suffi- ciently at any one time or under the right conditions for any great improvement to occur. On the other hand, they are used so frequently that the memory loss is insignificant after a period of no practice. As adults we are 011 a permanent plateau with respect to the efficiency of most customary acts: that drugs, lack of oxygen, emotional disturbances and environmental changes in general can produce greater or less fluctuations in efficiency, temporary in character, will now appear.
" Fatigue " Not a Serviceable Conception in Psychology. — Probably the most essential thing for the beginning student to do or for any scientific man planning to do research in the field of human work is to neglect most of the general discussions which have gathered around the subject of fatigue. James somewhere says about emotion: "But as far as 'scientific psychology' of the emotions goes I may have been surfeited by too much reading of classical work on the subject, but I should as lief read verbal descriptions of the shapes of the rocks on a New Hampshire farm as toil through them again." Much the same could be said about fatigue. The literature from the standpoint of discussion is complex and confusing and worthless both because it is not constructive and because it deters men from engaging in the study of the factors influencing the curve of work. Three reasons can be advanced for this condition: (1) and most important, confusion starts the moment the human animal is dissected into a so-called "mental" worker and "physical" worker. This is a most pernicious way of splitting up human activity. No matter what the human animal is doing he works as a whole. What measure of truth is to be found in this division can be better formulated by saying that certain activities, like splitting wood or dragging a cannon over muddy ground, demand the func- 350 PSYCHOLOGY tioning mainly of that part of the individual's organization con- nected with the use of the large muscles of the body. When we need a short phrase we characterize it simply as. manual work. To use the term manual in this broad way is, of course, to strip it of its etymological setting. When the individual is multi- plying or adding or planning the details of a lecture the process involves mainly that part of his organization connected with the small muscles employed in using words. Short characterizing phrases are subvocal work or vocal work, depending upon whether the work is done silently (thought) or spoken aloud. But neither in manual work nor in implicit laryngeal work does action take place only in the specified parts. The manual worker may be thinking of his family or of the nearness of meal-time, -whereas the laryngeal worker may be tearing his hair or walking up and down the room. (2) The attempt is made to literally drag in by the hair pictures of what goes on in the nervous system and the muscles. Thorndike, who in general stays closest to investi- gatable grounds, defines "mental work" as work done by the animal 's connection system. ' ' When, however, such a total activ- ity is examined more critically, it is found desirable to separate