XVIIIMeasuring the Mind
WHEN Professor Maturin discovered that his young friend Portia had become a student of psychology, he expressed no surprise, having learned where she was concerned to expect the unexpected. But he did voice his impression that the science was one that had, as yet, but an imperfect appreciation of the feminine mind. “Precisely,” replied Portia; “listen to this,” and opening one of her note-books, she read: “Our modern knowledge of woman represents her as primitive, conservative, nearer the savage than man. She is lighter, weaker, slower, less dexterous, less accurate, less individual. She is more nervous, more emotional, more superstitious, and more often insane. In short, her lack of accomplishment is due not to subjection, but to fundamental inferiority.”
“Now that,” concluded Portia, “was undoubtedly written by a man, and is therefore probably as mistaken as what men have usually written about women in novels and poems. At any rate, I intend to see for myself.” Professor Maturin immediately commended her intention, and subsequentlyfollowed her progress with an interest which, after a time, she rewarded by an invitation to visit the laboratory where she was working. It was not long, by the way, before she discovered that, although the particular statements of the German scientist she had quoted were in the main correct, an obsession of the Kaiser’s “church, children, cooking, and clothes” doctrine had made him ignore equally striking facts on the other side. Her other discoveries shall be given in Professor Maturin’s own words. “As we started on our expedition she read me a counter quotation, from an even more famous authority: ‘Woman is more observant, more assimilative, more sympathetic, more intuitional, more aesthetic, and more moral than man. She is more typical of the race and nearer the superman of the future. Man in comparison is senile, if not decadent.’
“My burst of admiration for a science that could solve the same problem in such opposite ways, was checked by Portia’s remarking that she attributed scarcely more importance to the latter than to the former statement. She was quite in accord with the directors of her laboratory, in considering much of what calls itself psychology to be based on philosophic deductionor popular generalization, rather than on scientific observation and experiment. As a matter of fact, scientific psychology, as a development of the present generation, was just beginning to find its accumulated facts sufficient for any generalization. This statement gave me a sense of entering a theatre just as the curtain was going up.
“After a glimpse at the general arrangement of the department’s score or more of rooms, Portia proceeded to lead me systematically through the suite devoted to physiological psychology. Concerning the sense of smell, little seemed to be known, except that it is sufficiently sensitive to detect a thimbleful of odorous gas diffused through a very large room. Not much more is known concerning taste, except that it can be stimulated electrically, as smell cannot be, and that sweet and sour are distinguished chiefly by the tip of the tongue; bitter and salt by the back.
“But discoveries in physics have made possible extensive studies of sound sensation. The average ear has a compass for sounds of from twenty-eight vibrations a second to twenty-two thousand, and can detect differences caused by a variation of sixty. The figures for sight are even more surprising. The sensation of red is caused by rays of light which vibrate from four hundred andforty to four hundred and seventy billion times a second. At this stage of my observations, I abandoned my memory for a pencil and note-book. Increasingly rapid vibrations produce the other colors, up to violet, which is caused by about seven hundred and twenty-two billions.
“It is not surprising, therefore, that the sense of sight displays considerable inertia. It takes a perceptible time for the eye to see what is before it, and its images persist after the object is removed or the eye is closed. Such after-images are at times like the object, but show its complementary color if the sense is fatigued. This last fact is said to be taken advantage of by department-store salesmen, who change fabrics of which their customers are wearied for others complementary in color. Pressure and temperature are felt only at certain spots on the body, very close together, but quite unevenly distributed. The forehead and the back, for example, are more sensitive to cold than to heat. Some spots are sensitive to heat or cold alone, seeming to indicate separate sets of nerves for these sensations.
“The lower limits of any sensation may be determined by gradually diminishing a stimulus until its effect is not noted, or by increasing a smaller stimulus until a sensation is produced.Delicacy of perception is measured by noting the smallest increase or decrease of stimulus needed to produce a change in sensation. Some persons can distinguish, by touch, a difference of half an ounce in a pound weight. Measured by the distance apart at which the points of a divider can be separately felt, the cheek is but half as sensitive as the finger, the finger but half as sensitive as the tongue. Hence, it is probably in order to touch as well as to taste that infants carry everything to the mouth. The direction of sounds is determined by the difference in the relative intensity of the sensation in the two ears; the position of the body, when the eyes are closed, is somehow felt by means of semi-circular canals in the ear. Measured by moving a candle away from an object until its shadow seems the same as that produced by a fixed candle, or by rotating disks bearing black lines on white, the eye can distinguish a difference of one one-hundredth in a quantity of light. Judging distance by sight is said to involve at least ten separate operations of perception and judgment, vision being really mental interpretation, based on association and memory as well as on sensation. Hence, errors in visual perception are so common that painters, sculptors, and architects always take theminto account. Estimates of distance with one eye alone are usually inaccurate; vertical seem longer than horizontal distances. The size of small objects and the speed of larger ones are usually underestimated; the speed of small bodies and the size of larger ones, exaggerated. Yet, in judgment of space, sight is more accurate than touch.
“The most interesting rooms of this series were those devoted to measuring the time of nervous and mental processes, by means of complicated and delicate machinery, electrical for the most part, and arranged so as to cause certain sense impressions, and to record the time between these and a response in some form of motion. Each experiment is repeated many times, with the same person, and with many persons, in order to eliminate errors due to inertia of after-impressions, to expectation or practice, to surprise or fatigue. In even so simple a procedure as pressing an electric button with one hand on feeling a touch on the other, nearly a dozen distinct elements were considered—stimulus of the sense organ, conduction through nerve and through brain, reception and transformation of the impulse, reconduction through brain and through nerve, and, finally, muscular action. The speedof nerve transmission being known as from one hundred and fifty to two hundred feet a second, it is possible to deduce the approximate rate of mental reception and action. It is not flattering to learn that electricity is about one thousand times as quick. The total reaction from hand to hand occupies from one-tenth to one-fifth of a second; the ear has approximately the same rate of action; the eye is about one-fourth slower. The mind’s interpretation of sensation averages about one-twenty-fifth of a second; its determination to act, a shade less.
“It takes less time to perceive color and form than letters or words, and all of these differ among themselves. The number three seems a sort of natural unit, it being almost as easy to perceive three objects at once, as one; it is much harder to perceive four. The imaginative reproduction of an image requires about one-fourth of a second; the association of abstract ideas, about three times as long—all according to the previous alteration or multiplication of the six hundred million or more brain cells which are the average individual’s stock in trade.
“The numerical records of all such experiments are transformed graphically into diagrams, whose bases represent the number of experiments,and whose heights represent the varying accomplishment. Such surfaces of frequency, as they are called, show at a glance the entire performance of the trait studied, and are therefore much superior to the ordinary method of averages. The intellectual average of a town that contained a university and an insane asylum would be about that of a town that had neither. A diagram, however, would show not only the average, but the much more significant distribution. Attention is also paid to the ‘mode,’ or measure that occurs most frequently, and to the ‘median,’ or record above and below which half of the measurements lie. Then, by calculating the average deviation from the average, and certain similar ratios, it is possible finally to obtain a small group of figures which contain the essence of the entire distribution. This, in turn, makes possible the measurement and the comparison not only of particular mental functions, but of the characteristic ability of individuals and of groups. In this way, for example, it has been found that mental activities vary in much the same manner as do the functions of most of the natural organs that have been measured by biologists, anthropologists, and physicians. In general, two-thirds of all mental performanceslie within the middle third of ability. Average efficiency is very near to the most common, and both lie about half-way between the two extremes.
“Perhaps the most striking result of such study is the discovery, by means of a large number of measurements, that mental functions are much more independent of one another than is usually thought, and that a change in one function alters another only so far as the two have identical elements. There is, for example, only a slight correlation between remembering numbers and remembering words, and no perceptible relation between perception of time and perception of rhythm, or between sense perception in general and memory. Judged from the grades given by instructors to several thousand school and college students, the natural sciences are closer to Latin, in the kind of ability they require, than they are to mathematics. Algebra and geometry are almost as different from one another as mathematics in general are from non-mathematical subjects.
“Such facts certainly seemed to warrant the conclusions of the professor to whose guidance Portia now consigned me: ‘The mind is not a functional unit, nor even a collection of generalfaculties which work irrespective of particular material. It is rather a multitude of separate functions, each closely related to only a few of the others, and to most in so slight a degree as to elude measurement. It is impossible to infer success in one field from success in another, or success in an entire subject from success in a part of it. To estimate the general ability of any individual requires the separate measurement of traits sufficiently numerous and well-chosen to represent fairly all of his capacities. By means of such specific measurements, however, we can determine pretty definitely an individual’s capability for any of the highly specialized activities, such as music or painting.’
“The rooms devoted to the study of genetic psychology, or mental development, contained much interesting data concerning the mental life of children, collected usually through very simple tests, such as estimating the size of geometrical figures, the length of lines, or the duration of sounds; arranging in graduation a series of weights, or the shades of a color; or recalling series of related or unrelated letters or words. While the material thus obtained seems to indicate the existence of certain general laws of mental growth, it is not yet considered sufficientto establish them. The implications are that the masculine mind is slightly more variable, the feminine slightly better in perception; and that the relation between early and later ability is one not of antagonism, but of resemblance.
“I wished that I might linger over the studies of rapidity of movement, tested by tapping; and of precision, tested by drawing lines in a narrow, intricate path, or by tapping in a small circle without touching the sides; and I would gladly have spent a day examining the ingenious contrivances for recording and measuring the attention demanded and the emotions aroused by different sorts of reading. But our time was growing so short that I was hurried on, after only a glimpse at a mass of material that would have delighted or distressed—I had not time to learn which—the heart of a spelling reformer—the records of the spelling of thirty-three thousand children! In this connection the professor remarked that his own experiments had convinced him that good spelling depended not on memory or on observation in general, but upon a certain specific ability to notice small differences in words, by means of sight, hearing, or, in the case of the blind, through touch.
“In the next, so-called ‘heredity room’ wererecords showing that children of the same parents are slightly more like one another than they are like the average, in height, color of eyes and hair, and in all the mental traits that have been studied in this connection. The physical traits of parents tend to alternate, their mental traits to blend, among their children. Eminent men are almost always found to have near relatives of eminence. Family resemblances are most marked in traits, like musical ability, that are least affected by environment. Here, too, were the life histories of many twins, showing that those closely alike at birth and in early rearing usually remained so in spite of later changes in environment; and that those unlike at birth remained so in spite of identity of nurture. From such and similar facts the department drew the conclusions that nature predominates greatly over nurture, that inheritance is specialized rather than general, and from the original nature of the parents rather than from acquired traits.
“Individuals who are subjected to the influence of a particular environment are usually so much more influenced by the forces that select them for that environment, that accurate knowledge in this field is obtainable only with difficulty. The fact, for example, that most Congressmenare college graduates is probably due not so much to their education as to their early giving evidence of ability that demanded such training. In the words of the professor: ‘The factor of selection is commonly neglected, the influence of environment commonly overestimated. Environment does not create, but merely selects and stimulates natural abilities. About all that education can do is to supply facilities for and remove obstacles to the growth of the brain, encourage desirable activities by making them pleasurable, and inhibit their opposites by making them uncomfortable. Mental hygiene, opportunity, and incentive are the foundations of the teacher’s Blackstone.’
“I was prepared to be impressed most of all by what Portia called the ‘human-nature room,’ for here were printed records of many studies based on answers to widely circulated ‘questionnaires.’ From one set it was deduced that half of us have favorite sounds, open vowels and liquid consonants leading; one-fourth are fond of particular words, ‘murmur’ being the choice of the majority; most people are fond of particular names, ‘Helen’ being the prime favorite. Similar records showed that women read more than men, but reach the period of maximum reading sooner,the greatest reading age being about twenty, the average amount small after thirty-five, most people reading for emotional rather than intellectual reasons. Yet others indicated that muscular power increases and attention decreases in summer, the mind being at its best from December until April.
“I was concluding that here was a very mine of richness for the novelist, when the professor remarked: ‘We attribute small importance to this sort of thing. Conclusions based on reports from artificially selected and incompetent observers and combined in an unscientific manner have no general validity. Only direct expert observation of representative cases, and accurate statistical study of all the factors involved, can bring reliable results. We may base our educational ideals on philosophic or popular theories, but our study of the nature of mind and the ways of affecting it, to be at all valuable, must be rigidly scientific.’
“Well, I had learned enough and to spare without these suggestive, if inaccurate, observations of general human nature, and without even looking into certain rooms, where zoölogists and psychologists united in studying the development of mind in the animal world.
“‘I presume,’ I remarked to Portia as we left the building, ‘that when you come to consider suitors for your daughters, you will inquire into not their social and financial standing, but their personal equations of perception and motor-activity, and request statistics concerning the central tendency and variability of each of their mental and moral traits?’ ‘Undoubtedly,’ she replied, ‘and I should want to know similar facts for their parents, and also the details of their reaction to humidity and to heat.’
“‘Shall you require similar data concerning the prospective father of those daughters?’ I asked. ‘Perhaps,’ she concluded; ‘but considering the present undeveloped state of the science, I should insist on conducting those investigations myself. Just now I have no time for such experiments. I must to a lecture. Good-bye.’
“Thus Portia left me to proceed to my lunch and to cogitate alone, a more confirmed perfectibilian than ever, marvelling at the achievement of this generation, and half prepared to accept as true an inscription that I had seen in the last room we visited: ‘Psychology has a message to the world, richer and more original than that of the Renaissance.’”