Part 15

FIG. 14a.

FIG. 14b.

FIGS. 14, 14a, and 14b.--The two views of Fig. 14 described in the text are brought out more clearly in Figs. 14a and 14b. The shaded portion tends to be regarded as the nearer face. Fig. 14a is more apt to suggest the steps seen as we ascend them. Fig. 14b seems to represent the hollowed-out structure underneath the steps. But even with the shading the dual interpretation is possible, though less obvious.]

The blocks in Fig. 15 are subject to a marked fluctuation. Now the black surfaces represent the bottoms of the blocks, all pointing downward and to the left, and now the black surfaces have changed and have become the tops, pointing upward and to the right. For some the changes come at will; for others they seem to come unexpectedly, but all are aided by anticipating mentally the nature of the transformation. The effect here is quite striking, the blocks seeming almost animated and moving through space. In Fig. 16 a similar arrangement serves to create an illusion as to the real number of blocks present. If viewed in one way--the black surface forming the tops of the blocks--there seem to be six, arranged as in Fig. 17; but when the transformation has taken place and the black surfaces have become the overhanging bottoms of the boxes, there are seven, arranged as in Fig. 18. Somewhat different, but still belonging to the group of ambiguous figures, is the ingenious conceit of the duck-rabbit shown in Fig. 19. When it is a rabbit, the face looks to the right and a pair of ears are conspicuous behind; when it is a duck, the face looks to the left and the ears have been changed into the bill. Most observers find it difficult to hold either interpretation steadily, the fluctuations being frequent, and coming as a surprise.

FIG. 16a.

FIG. 16b.

FIGS. 16, 16a, and 16b.--How many blocks are there in this pile? Six or seven? Note the change in arrangement of the blocks as they change in number from six to seven. This change is described in the text. Figs. 16a and 16b show the two phases of a group of any three of the blocks. The arrangement of a pyramid of six blocks seems the more stable and is usually first suggested; but hold the page inverted, and you will probably see the alternate arrangement (with, however, the black surfaces still forming the tops). And once knowing what to look for, you will very likely be able to see either arrangement, whether the diagram be held inverted or not. This method of viewing the figures upside down and in other positions is also suggested to bring out the changes indicated in Figs. 12, 12a, 12b, and in Figs. 14, 14a, 14b.]

FIG. 18.

T indicates that the shaded portion of Fig. 16 in this view represents the top of a block; B that in the other view it represents the bottom.]

This collection of diagrams serves to illustrate the principle that when the objective features are ambiguous, we see one thing or another according to the impression that is in the mind's eye; what the objective factors lack in definiteness the subjective ones supply, while familiarity, prepossession, as well as other circumstances influence the result. These illustrations show conclusively that seeing is not wholly an objective matter depending upon what there is to be seen, but is very considerably a subjective matter, depending upon the eye that sees. To the same observer a given arrangement of lines now appears as the representation of one object and now of another; and from the same objective experience, especially in instances that demand a somewhat complicated exercise of the senses, different observers derive very different impressions.

Not only when the sense-impressions are ambiguous or defective, but when they are vague--when the light is dim or the forms obscure--does the mind's eye eke out the imperfections of physical vision. The vague conformations of drapery and make-up that are identified and recognized in spiritualistic séances illustrate extreme instances of this process. The whitewashed tree or post that momentarily startles us in a dark country lane takes on the guise that expectancy gives it. The mental predisposition here becomes the dominant factor, and the timid see as ghosts what their more sturdy companions recognize as whitewashed posts. Such experiences we ascribe to the action of suggestion and imagination--the cloud "that's almost in shape like a camel," or "like a weasel," or "like a whale." But throughout our visual experiences there runs this double strain, now mainly outward and now mainly inward, from the simplest excitements of the retina up to the realms where fancy soars free from the confines of sense, and the objective finds its occupation gone.

FOOTNOTE:

In order to obtain the effects described in the various illustrations it is necessary in several cases to regard the figures for a considerable time and with close attention. The reader is requested not to give up in case the first attempt to secure the effect is not successful, but to continue the effort for a reasonable period. Individuals differ considerably in the readiness with which they obtain such effects; in some cases, such devices as holding the diagrams inverted, or at an angle, or viewing them with the eyes half closed, are helpful.

MENTAL PREPOSSESSION AND INERTIA

Those who are actively engaged in educational pursuits are called upon from time to time to consider the nature of the difficulties in the imparting of knowledge, the psychological impediments that stand in the way of successful instruction. These are many and various; and pertain as well to the givers as to the receivers of learning. This large and well threshed field I have no intention of gleaning once more; I desire simply to draw attention to one form of difficulty on the part of the learner, which has been brought home to me so frequently and at times so forcibly, that I should be inclined to select it as the most salient stumbling-block in the successful acquisition of those branches of study which it falls to my lot to expound.

This characteristic, which may be called mental prepossession, is well illustrated in the following narrative, the truth of which, however, is not guaranteed. The story dates from the exciting days when the American public was completely fascinated by the mental gymnastics of the "spelling bee;" and relates that towards the close of a very fierce contest with the alphabet, when only a few stalwart champions remained to encounter the erratic eccentricities of English orthography, the conductor of the "bee" announced with an air of grave importance a word that he felt quite certain would retire not a few of the spelling virtuosi. He then asked their closest attention to his precise pronunciation, and solemnly gave utterance to what for all the world sounded like cat. Each hearer attempted to spell this extraordinarily difficult word with a suitably unusual rearrangement of the letters suggested by the sound, and when each effort had in turn been pronounced a failure, the information was given that the correct spelling was c-a-t. Hæc fabula docet that when one expects a difficulty he is apt to find it or to make it. Believing the problem to be unusual, he applies unusual methods to its solution; believing it to be complex, he overlooks the simple means by which its mysteries may be unlocked. It matters little how this reputation has come about, whether as the result of personal prejudice or of inherited tradition, whether suggested by the technicality of the subject or the awkwardness of the treatment, whether by the use of a few unusual terms or operations, or by any one of the countless methods, conscious and unconscious, by which such impressions are formed,--the result will be much the same.

Many a student approaches a study such as psychology or logic with an unshakable conviction that he is about to consider matters abstruse and difficult; things totally unrelated to what he has studied elsewhere or experienced before, and accordingly requiring an exercise of the mental faculties as different as possible from that to which he has been accustomed. It is not altogether strange that such notions should be current, because the tradition to that effect is ancient and strong, and originated in times when scholars generally, and philosophers perhaps more than others, took pride in exclusive erudition, in the possession of a more or less esoteric wisdom quite unrelated to the knowing and the thinking of οἱ πολλοί [Greek: hoi polloi]. It requires the combined operation of long periods of time and of persistent effort to weaken such beliefs; and it is only within recent times that the notion has been successfully disseminated that the processes considered in psychology and logic derive their validity from our daily experience, and require for their comprehension no mental gymnastics or intellectual contortions; that in brief these sciences simply aim to systematize and improve, to interpret and explain the every-day processes by which knowledge is gained. This, at all events, is one of their functions, and one profitably emphasized in the introductory study of their scope and content.

When one has once formed the impression, or has had it produced or suggested for him, that the study or the task he is about to attack is a difficult one, his mental powers are at once sufficiently reduced to make it really difficult; the signal is given of an approaching intricate turn in the road, the brakes are turned on, and the train of thought creeps along slowly. Mental prepossession leads to mental inertia. The same question which the student would answer readily and fully when asked by a friend as an item of general information, becomes utterly beyond his comprehension when it appears in the text-book, the title-page of which bears the ominous name of one or other of the studies reputed as difficult. The mind is not properly set; there is little receptiveness, little alertness. When we are asked in a conundrum-like tone, why one thing is like another, we ignore obvious and simple resemblances, and look about for obscure ones. The student who labors under the illusion that psychology is a maze of conundrums, employs mental processes appropriate to such a pursuit. The schoolboy finds it impossible to answer a question in arithmetic during the geography lesson, and the same lack of adaptability is shown by his older counterpart when he greets the answer to a very simple question (which, however, he himself failed to answer) with the all too familiar, "Oh, of course I knew that." Perhaps the most extreme instance of the many that I could cite is that of a student so irresponsive and apparently at sea regarding the topic under discussion--the senses--as to force me to ask him, "With what do you hear?" and who answered with perfect sincerity, "I don't know." This was a psychological question, and as such became as difficult as the spelling of cat at the end of a "spelling bee."

When the student has been made to feel that the questions he is asked can be answered from his everyday experience, and that common sense is often quite as serviceable a guide as special knowledge, a progress ensues in every way satisfactory. Such a conviction, however, is not a matter of verbal acknowledgment; it yields slowly to explanation and proceeds somewhat unconsciously and inwardly. Moreover, it is a trait very sensitive to the power of contagion, so that a comparatively small proportion of the class may successfully spread this mental attitude to the whole number. A question which two or three have failed to answer becomes invested with a spurious difficulty which makes it a deep mystery to all the others.

This mental prepossession may at times have quite different and curious results. When, for instance, the goal to be reached is given, when the answer may be looked up in the back of the book, it is surprising what peculiar and irrational steps will be taken to secure and justify the answer so given. This is all the more striking when the answer happens to be wrong; however simply such error may be discovered, the prepossessed mind will work away until by a more or less roundabout procedure the desired answer is reached. A noted professor of chemistry has an apt illustration of such a case. In a chemical test his assistant by mistake referred the class to the wrong bottle, so that the substance which the correct liquid would have dissolved could not be at all dissolved in the liquid actually used. However, on the professor's next round in his laboratory nearly every student assured him that the substance had dissolved, and a few went so far as to describe the precise manner of its dissolution.

It is quite clear that illustrations of mental prepossession, as also of inertia, may be found in many of the industries and occupations of life. The bicycle has added a very characteristic one. At a certain stage in the acquisition of the art of cycling, there comes a time when every obstacle and irregularity in the road absorbs the attention of the rider with a fascination that is quite irresistible. The rider is so possessed with the idea that he or she is going to run into the post or the curb or a rut or another vehicle, that the dreaded calamity may actually ensue. When the attention can be directed to the clear pathway, and the obstacles driven out from the focus of attention, the difficulty is surmounted. So in jumping or running and in other athletic trials, the entertainment of the notion of a possible failure to reach the mark lessens the intensity of one's effort, and prevents the accomplishment of one's best. He who hesitates is lost, because the hesitation makes possible the suggestion of a failure, the prepossession by a sense of difficulty.

Some of the illustrations of prepossession are somewhat trivial; others more important, but perhaps not so definite as might be desired. It is seldom that an instance of this propensity can be pointed out in which an accurate and quantitative comparison may be made between the possessed and the unpossessed mind. One such illustration, which seems to me comprehensive and significant, is worthy of more detailed record. It is derived from the experience of the United States Census office in 1890, in tabulating the returns of the enumeration by means of machines specially devised for this purpose. I give an account of the manipulation of these machines in the words of one who had an intimate acquaintance with their use, and add italics to emphasize the points of special psychological significance.

"The adoption of Mr. Hollerith's tabulating machine for counting the population of the country according, at one and the same time, to sex, color, age, marital condition, nationality, occupation or profession, language and school attendance presented an entirely novel problem to the office. The machines having never been used for any purpose, there was no previous experience by which to act or on which to predicate results. The necessity was upon the office of employing for a very limited time (ninety days) at least five hundred people for this work alone, in addition to the one thousand who could be taken from other branches of the work and placed on this one. Every one, including Mr. Hollerith himself, felt that the rapid and accurate use of the punching machines called for a degree of cultivated intelligence not possessed by every clerk. So much for the mental attitude.

"The clerks (an instructor for every twenty) were taught to edit the family schedules from which the count was to be made, thus learning thoroughly how to read and classify the returns. In order to accommodate the returns to the capacity of a punching machine, a great variety of symbols were adopted for occupations and professions: thus Ad was used for farmer: Ac for farm hands: Kd for merchants: Gd for agents, etc., through twenty-four two-columned octavo pages of ordinary type. Some one symbol must be used for each occupation recorded, and the use of the symbols must be learned, and, for rapid work, they must be committed to memory. After five weeks of editing, one by one, the most reliable and intelligent workers were set to use the punching machines. The task is much like that of using a typewriter, substituting for keys a movable punch which passes through lettered holes, and in place of the forty keys of an ordinary typewriter, about two hundred and fifty holes are to be learned.

"Mr. Hollerith set the number of cards for a day's work at 550. (Each finished card contained, on the average, 10 holes.) It was two weeks before that number of cards was reached by any clerk, and that only in exceptional cases. Then the entire force of the division was set to work. In two weeks most of them had reached five hundred, and the average was daily increasing. These clerks worked at first from edited schedules; that is, those on which had been written the symbols to be punched on the machine. A roll of honor was made out daily showing the highest records, and in a week the clerks were doing from six hundred to fifteen hundred a day, but at a great cost of nervous force. So severe was the nervous strain that complaints were made to the Secretary of the Interior, who forbade any further posting of daily reports, and instead an order was posted that no clerk was required to do more than such a day's work as he or she could readily perform, and that no arbitrary number was required of any one.

"After the work was well under way about two hundred new clerks were put into one room and scattered through the force already at work. They had no experience with schedules, knew nothing of the symbols, had never seen the machines. They saw those around them working easily and rapidly, and in THREE DAYS SEVERAL OF THEM HAD DONE FIVE HUNDRED, IN A WEEK NEARLY EVERY ONE, while the general average was rising. There was no longer any question of nervous strain, and one of these temporary clerks the day before she left beat the record by doing 2,230. I think the influence of the mental attitude quite as remarkable in the matter of their doing the work easily as in that of doing it rapidly. During the first month many were actually sick from overwork when doing seven hundred, while after that time the idea that the work was unusually trying was never referred to. Another significant fact is that after the posting of the daily record was abolished there was no falling off in the daily average, as had been anticipated, while complaints of overwork necessarily ceased."

It is thus demonstrated that an unskilled clerk, with an environment proving the possibility of a task and suggesting its easy accomplishment, can in three days succeed in doing what a skilled clerk, with a preliminary acquaintance of five weeks with the symbols to be used, could do only after two weeks' practice; and this because the latter, doubtless not a whit inferior in ability, had been led to regard his task as difficult.

III