Testing the Human Mind

The army mental tests have shown that there are, roughly, forty-five million people in this country who have no sense. Their mental powers will never be greater than those of twelve-year-old children. The vast majority of these will never attain even this meagre intelligence. Besides the forty-five millions who have no sense, but a majority of votes, there are twenty-five millions who have a little sense. Their capacity for mental and spiritual growth is only that of thirteenor fourteen-year-old children, and your education can add nothing to their intelligence. Next, there are twenty-five millions with fair-to-middling sense. They have n’t much, but what there is, is good. Then, lastly, there are a few over four millions who have a great deal of sense. They have the thing we call ‘brains.’

THESE statements, which I venture to quote from a popular magazine, are typical of much that has been written about ‘army mental tests.’ Are they true? No. Is there any truth in them? Just enough to make them worse than false. They discredit psychology and mislead the reader in important matters of fact. This is my excuse for turning from my scientific tasks to write a would-be popular article on the results of psychological examining in the army.

Two types of statement appear repeatedly in popular and general accounts of the army work. The one is that the draft was but thirteen years old mentally; the other that some 12 per cent of the soldiers were of very superior, or superior, intelligence, as indicated by the grades A or B; some 64 per cent, of medium ability, grades C+, C, and C-; and the remaining 24 per cent, of poor, or very poor, mental alertness, and therefore graded D or D —. Unfortunately, both of these ways of expressing the general results of army mental examining are seriously misleading. It is my task to point out the chief reasons for misunderstanding, and to offer some more intelligible and reliable form of statement.

I

Is our population only thirteen years old mentally? There are at least two possible grounds for dissatisfaction with the thirteen-year statement. On the one hand, it may be misunderstood or misinterpreted by most of us, and on the other hand it may be unreliable or inaccurate. Let me mention first a few possible grounds for misinterpretation.

It is well known that most of us commonly overestimate the intelligence of our fellows. This is primarily because of our limited contact and familiarity with persons of low-grade ability. I would not flatter the Atlantic circle, but it is undoubtedly true that its average intelligence is far above the median ability of the population! Inevitably we estimate the intelligence of mankind from that of the individuals whom we know.

Similarly we underestimate the native intelligence of the average thirteenyear-old child. For we are greatly impressed by the maturing influence of education and experience beyond the age of thirteen, and we tend to attribute to inborn intelligence what, instead, is purely acquisition. A child of thirteen years ordinarily is well advanced in growth, and may well have attained maximum intelligence, although still capable of vast improvement in the use of intellect. Children are sexually mature at from ten to sixteen years, according to race, and climatic conditions. It would not be very surprising, in view of these facts, were it proved that intelligence is fully developed in some individuals by the age of thirteen, and in the majority before sixteen. Such considerations make the thirteen-year statement more credible.

Or, again, it is entirely possible that the draft was not a fair and representative sample of the men of the country. To a certain extent those of low-grade intelligence were shielded by parents or guardians, and were rejected by draft boards. And to a far greater extent, probably, men of first-rate intelligence were reserved for the conduct of essential occupations, or were trained as officers. This heavy elimination at the top probably reduced the mental age of the drafted army by at least one year.

Nor can we safely overlook the effect of men of foreign birth on the intellectual status of the army. Altogether they are markedly inferior in mental alertness to the native-born American. In the group of soldiers especially studied by the psychologists, about 18 per cent were foreign-born. The United States Census reports for the total population about 14 per cent of foreign birth; so the draft was somewhat more heavily weighted than is the total population. Whereas the mental age of the American-born soldier is between thirteen and fourteen years, according to army statistics, that of the soldier of foreign birth serving in our army is less than twelve years. To claim, then, that the inclusion of foreigners lowers the average mental age of the group by one half-year certainly is conservative.

If we should sum up these various considerations, we might say that the mental age of the native-born American male within the age-range of the draft probably approximates fifteen years. Such a result of army mental tests would not have caused general surprise, alarm, or skepticism.

Turning now from the possibilities of misinterpretation to those of error, we should remember that the trustworthiness of the mental-age statement issued by army psychologists depends upon the value of the standards of judgment available from civilian sources. Now, it is definitely known that the mentalage standards for ages from five years to ten or twelve are fairly reliable, and that beyond twelve years they are of uncertain value. This casts serious doubt on the trustworthiness of the thirteen-year statement. So also does the fact that the average age of maximum native intelligence probably is nearer sixteen than thirteen years. It is but fair to say that mental age was not generally used by army psychologists as a method of stating the result of examination. Instead, the actual score made in examination was recorded and used as a basis for recommendation.

I confess that I am not at all concerned, much less alarmed, by the statement that the average mental age of the draft was but slightly more than thirteen years. In view of all the possibilities of adverse selection, of the inclusion of a large percentage of men of foreign birth, of the probable unreliability of mental-age standards for adolescents and adults, and the near certainty that intelligence does not reach its maximum, on the average, much before sixteen years, it seems to me that thirteen years is a very respectable showing for our army.

Happily, the results of intelligence measurement of nearly two million soldiers do not stand or fall with the thirteen-year statement. It is merely a sort of by-product offered to the public by the army psychologist, on the mistaken assumption that it would be more intelligible and less likely to be misinterpreted than such descriptions of results in terms of examination scores and their distributions as I shall now present.

II

Scarcely less a popular stimulant. — or shall we say irritant — than the thirteen-year-mental-age statement, which we have put aside, is the often quoted distribution of letter grades in the army. It is on this doubtless that Mr. Wiggam, whose statements introduce this article, based his misleading paragraph. The alarmist now tells us that army measurements indicate that there is not more than 12 per cent of really good intelligence in our population, whereas low grades of intelligence are at least twice as frequent. This would be alarming, I grant, if true. But is it true? The lay readers of army reports have overlooked, or ignored, the important fact that the frequency and distribution of letter grades of intelligence depend wholly upon the definition of the letter grades formulated by the army psychologists. Grade A, for example, was so defined in terms of the range of scores which it should include, that not more than 5 per cent of the men examined should receive it. Or, differently expressed, the army psychologists, by arbitrary definition and ruling, limited the number of soldiers who should be classed as of A intelligence. Why then become alarmed over the infrequency of A men!

There was, to be sure, nothing arbitrary about the scores made in their examinations by the tens of thousands of soldiers, or about the distribution of these scores. It was only the grouping of scores that was arbitrary, and merely a matter of convenience in connection with military use. Letter-grade distribution of intelligence is wholly valueless as a description of the intellectual status of the draft; for there might just as well have been twice as many A and B men as D or D — men, as the reverse. It is solely a matter of definition! The letter grades are useful, though, in comparing different army groups, — such, for example, as officers and privates, whites and blacks, English and Irish, native-born and foreign-born,—for the definitions remain constant.

III

Having cast aside as misleading, or valueless, the statements that our army was only thirteen years old mentally, and that there were more than twice as many men of inferior as of superior intelligence, we must substitute some reasonably safe way of stating the general result of psychological measurement. Probably the most satisfactory terms of statement are those of the ‘combined scale’; for the results of all the different kinds of examination were reduced finally to terms of a single scale, the range of which was from zero to 26 points. On this scale the median score — that is, the score which has as many cases above as below it — for the white draft is 13.46 points; that for officers, 18.84; for white soldiers discharged from the army because mentally incompetent, 6.8.

The extreme differences in intelligence between important groups of men within the army are still more impressively shown by the percentage of individuals falling below a certain score. We may arbitrarily take fourteen points, which is very near the median score for the white draft, as our standard of comparison. It then appears that of commissioned officers only 1.6 per cent fall below the standard; of the white draft, 59.4 per cent; of the negro draft, 93.2 per cent; of men of the white draft who had to be examined individually, 98.2 per cent (the same figure applies to the negro draft as individually examined); of men of the white draft discharged from the army as mentally incompetent, 96.8 per cent; of men of the negro draft discharged from the army, 100 per cent. These figures are valuable as indicating alike the differentiation of the groups and the prevalence of below-average intelligence in certain of them.¹

How do we commonly estimate intelligence? Scores and percentages mean little to us, unless we can somehow relate them to occupational or other forms of behavior, by which we ordinarily judge a person’s ‘brightness’ or mental ability. Such comparison is possible because of the army’s classification of men according to their civilian occupations, and the relating of intelligence scores to occupation. The average intelligence of the army is just about the same as the averages for such important occupational groups as horse-shoer, brick-layer, cook, baker, painter, general blacksmith, general carpenter, butcher, general machinist, riveter, telephone lineman, pipe-fitter, plumber. Of course, not all the men engaged in these trades have precisely average draft intelligence. Some are lower, some considerably higher. Our statement implies that the average intelligence found in a given occupation approximates the average for the white draft. The average intelligence in the army for such occupations as common laborer, miner, teamster, barber, is much lower than the average for the entire draft. On the oilier hand that for clerks, bookkeepers, draftsmen, accountants, dentists, engineers, doctors, clergymen, is very much higher. There are notable and tragic exceptions; but, in general, persons gravitate toward the class of occupation which most nearly suits their intellectual ability and temperament.

No one who is familiar with the facts would think of denying a high grade of intellectual ability to the commissioned officers of the United States Army. As a group, they were during the war, and are now, superior in endowment and education. The distribution of their intelligence grades strikingly confirms this assertion. Only three tenths of one per cent of the more than forty thousand white officers examined graded below C—; 3.3 per cent received the grade of C; 12.5 per cent received C+; 28.4 per cent, B; 55 per cent received A. These figures are eloquent; for we know what such men stand for in community and nation. By virtue of their superior ability, they are the leaders industrially, professionally, educationally, socially. It is a long step from the average intelligence of 1 he white draft to that of the commissioned white officer. In the former, 72.9 per cent graded C or less; in the latter, 3.6 per cent.

We have rather good practical knowledge also of the performance and possibilities of those men who never progress beyond the sphere of the ‘common laborer.’ Almost all the soldiers classified in this group occupationally graded below average in intelligence. Indeed, the majority received the grades C —, D, or D —, which, by interpretation, mean low average to very poor intellectual ability.

The cost of low-grade intelligence to the army was appalling. Among the men of the white draft, army psychologists discovered about two in every hundred who were so inferior mentally that they could not safely be assigned to regular military training and duty. This justifies the statement that in our army of five million men, there were at least one hundred thousand with very low-grade intelligence. Some of these were discharged after psychological examination, but many were retained, and used in labor battalions or otherwise. Probably most of them were not worth what it cost the Government to draft, equip, train, and insure them, and to pay the other costs incident to their military service and its hazards. The initial rejection, on the basis of psychological examination, of this entire group of one hundred thousand men would have saved the United States enough to pay the cost of psychological service a hundred times over.

IV

Any citizen should be interested in relations of illiteracy, schooling, and intelligence. As bearing on the educational status of our population, the following figures are illuminating. Only about 70 per cent of the soldiers examined were able to do themselves justice in the group examination intended for men who could read and write English. The remaining 30 per cent had to be given either individual examinations, or the group examination for those who were wholly illiterate, or illiterate in English. The soldiers classed by army psychologists as illiterate in English were unable to read newspapers or to write letters. Many of them undoubtedly could spell out words, and thus read with painful labor and slowness. But so much education as this profits the individual little and the nation less. Can we fairly consider ourselves a generally and highly educated people so long as three individuals out of every ten (this proportion certainly would be increased if the agerange were extended from fifteen to fifty years, and women as well as men were considered) can neither read nor write the language of our country?

Men who reported not more than four years of schooling scored on the average 22 points out of a possible 212 in examination Alpha; those with five to eight years schooling scored 51 points; those with one or more years of high school, 92 points; those with college training, 118 points; those with technical or professional training beyond college, 146 points. These figures might be interpreted to mean that intellectual ability is largely the result of education. Indeed, it is quite commonly believed that intelligence increases with schooling. This, however, is flatly contradicted by results of research, for it turns out that the main reason that intelligence status improves with years of schooling is the elimination of the less capable pupil. All along the line, from kindergarten to professional school, the less able and less fortunate in home conditions tend to drop out. Not more than 50 per cent of our population are capable of satisfactorily completing the work of a first-rate high school. The remainder reach their limit of educability along intellectual lines at varying points on the educational ladder. Not more than 10 per cent of the population are intellectually capable of meeting the requirements for a bachelor’s degree in a reputable college. Education, instead of increasing our intellectual capacity, merely develops it and facilitates its use.

Although army psychologists made no special study of illiteracy, they incidentally discovered the proportions of men among the native-born, the foreign-born, and American negroes who could read and write English to a useful degree. The illiteracy showing of New England may readily be grasped by examination of the above table.

Among the native-born in New England, illiteracy is least in Connecticut, 9 per cent, and next in Massachusetts, 11.5 per cent. Perhaps this indicates the difference in community service between Yale and Harvard! The percentage of illiterates for New England — 31, nearly one-third of the population— is amazingly high; but of special import for our social status and outlook is the prevalence of illiteracy among the native-born to the extent of more than 16 per cent.

If psychological examining in the United States Army had done nothing more than reveal the prevalence of illiteracy, it would have been well worth while as a service to the nation.

V

What of the intelligence of different races? Some years ago I read a book whose thesis was ‘Mind is fundamentally one and the same for mankind.’ If this is true, so also is the thesis that body — including such traits as haircolor and texture, complexion, height, cranial capacity — is essentially the same for all mankind. I have marveled that the learned gentleman found it in his heart to write so much with the hope of establishing what, obviously, is false! If we may safely judge by the army measurements of intelligence, races are quite as significantly different as individuals. To begin at home, the negro versus the white offers particularly valuable material for study.

If intelligence is fundamentally the same in negroes and whites, the distribution of the letter grades shown below is puzzling.

The education of the negro is poor in comparison with that of the white. Most of them are illiterate; but this fact accounts only in small degree for the prevalence of low grades, D— and D, in the intelligence examination. The contrasting results for Northern and Southern negroes is doubtless significant of selective action. The more energetic, progressive, mentally alert members of the race have moved northward, to improved educational and vocational opportunities for themselves and their children.

The intellectual status of the negro is greatly inferior to that of the white, and the figures already presented as typical are supported by measurements of the practical value of the negro soldier and by the opinions of commanding officers, who agree that he lacks initiative, displays little leadership, and cannot safely accept responsibility.

Almost as great as the intellectual difference between negro and white in the army are the differences between white racial groups.

Of natives of England serving in the United States Army only 8.7 per cent graded D or lower in intelligence; of natives of Poland, 69.9 per cent. In the English group, 19.7 per cent graded A or B, and in the Polish group, one half of one per cent. The race differences are so pronounced, and of such obvious practical significance in connection with immigration, that it seems excusable to present the rank order of the several racial groups, first, for increasing frequency of inferior intelligence, second, for diminishing frequency of superior intelligence, and, finally, for decreasing average score on the ‘combined scale.’

The measurements of intelligence for

different races are appreciably influenced by familiarity with English and facility in its use, as well as by amount of schooling. However, there is no reason to suppose that the English or Scotch have marked advantage over the Irish in their familiarity with the English language. Nevertheless, the English and Scotch groups show few intellectual inferiors and many superiors; whereas for the Irish group the reverse is the case. More than 39 per cent of the Irish graded D or lower, and only 4 per cent graded A or B.

The tragically poor showing, in these racial statistics, of the Italian and Polish groups is worthy of particular note, because these races at present figure so conspicuously among our immigrants.

Dr. Carl C. Brigham of Princeton University has recently reëxamined and carefully analyzed the army data bearing on nativity and length of residence in the United States. His results have not yet been published, but I am permitted to say that, in the main, they confirm the statements of this article. He has studied with care the intelligence of immigrants for different periods of the history of our country, and has discovered rather marked diminution of intelligence, which seemingly is due to change in the proportions of immigrants from Northern and Southern Europe.

For the past ten years or so the intellectual status of immigrants has been disquietingly low. Perhaps this is because of the dominance of the Mediterranean races, as contrasted with the Nordic and Alpine.

By some people meagre intelligence in immigrants has been considered an industrial necessity and blessing; but when all the available facts are faced squarely, it looks more like a burden. Certainly the results of psychological examining in the United States Army establish the relation of inferior intelligence to delinquency and crime, and justify the belief that a country which encourages, or even permits, the immigration of simple-minded, uneducated, defective, diseased, or criminalistic persons, because it needs cheap labor, seeks trouble in the shape of public expense.

It might almost be said that whoever desires high taxes, full almshouses, a constantly increasing number of schools for defectives, of correctional institutions, penitentiaries, hospitals, and special classes in our public schools, should by all means work for unrestricted and non-selective immigration.

VI

Crime, delinquency, and dependency, as well as educability, are intimately related to intellectual ability. For, when records of special and summary courts-martial are related to measurements of intelligence, it appears that men of low-grade intelligence are particularly prone to minor delinquencies, or infractions of military regulations. In one camp, of 929 courtmartial cases, 44 per cent were men of D —grade intelligence or lower, and less than 6 per cent of men graded A or B.

A chart used by army psychologists to exhibit graphically differences in intelligence between various groups, and to illustrate practical applications of mental measurement, shows the following startling facts. Of men with very poor, or poor, intellectual ability, who received in the examinations D, D —, or E, there were none among commissioned officers; very few among students in officers’ training-schools; less than one per cent among sergeants and corporals; something like 20 per cent among white recruits; and, by contrast with the above, among ‘disciplinary cases,’ men ranked by their officers as of ‘low military value’ or ‘unteachable,’ from 50 to 75 per cent. The graphic representation of these facts was impressive. It became more so as officers observed their men, and discovered for themselves that their estimates of military value agreed pretty closely with the intelligence grades supplied by the psychologist.

These figures suggest a way in which our army might have used intelligence measurements to excellent purpose. The elimination of the lowest ten per cent of the draft would have lessened by one half the waste and annoyance incident to military offenses, slowness and refractoriness in training, weakness and inefficiency.

The psychological examination of drafted men and other recruits was proposed originally as a quick, inexpensive, and reasonably sure way of discovering and eliminating men with too little intelligence to be worth training for regular military duty. But, as soon as the practical work of making psychological examinations was under way in the army, new uses of its results revealed themselves; and when the official inspector stated the purposes of examining, in his report to the Surgeon-General, he mentioned three important types: namely, the discovery and, as desirable, the elimination of the mentally defective; the classification of all men according to their intellectual ability; and assistance in the selection of men especially suitable for positions of responsibility, as in the case of commissioned officers.

In summary appraisal of results, it may be said that psychological examining in the United States Army had many and considerable direct and indirect values. It focused the attention of thousands of intelligent army officers — many of whom have now returned to civil life, taking their new knowledge of psychology with them — on the possibility and practicability of measuring human traits, and of using the resulting information for the benefit of mankind. It led to the improving of old and the devising of new methods of mental measurement, such as would not, ordinarily, have become available in a score of years. It provided data on intelligence, its distributions, and relations, unprecedented alike in quantity and in value. It increased the faith of psychologists in their professional work, and greatly stimulated them to concentrated labor on methods, problems of mental development, and the relations of intellectual ability to professional and other demands.

VII

Looking forward! Popular appreciation of the need for knowledge of man has increased rapidly in our times. The more daring are clamoring for branches of human engineering which, with curative and preventive medicine and hygiene, shall take their place beside civil, mechanical, electrical, chemical, mining, and those other well-established varieties of engineering that have to do with our environment rather than with ourselves. The idea that man’s chief study is man, is old. The conviction that the study of ourselves should enable us more wisely to direct and control our lives and our civilization, is new.

Tending to supplant the belief that whatever happens is definitely foreordained, and that it is our duty to accept meekly, and with what cheerfulness we can command, both good and ill, is the conviction that we are active, creative parts of the definite scheme of things, and that intimate knowledge and control of human behavior may just as well have been foreordained as anything else! Bitter and bloody was the opposition to the dissection of the human body; to efforts toward discovering the functions of our bodily organs; to attempts to prevent or avoid certain diseases. Persisting even to-day is the suspicion that insanity is a species of demoniacal possession and perhaps a divine visitation. Religious opposition to an increased knowledge of man’s origin and development, of the laws of growth, of the relations of bodily functions and mental processes to the world in which we live, continues to manifest itself. But, despite ancient beliefs and superstitions, traditions and prejudices, there is growing desire to know about the self as a natural object; eagerness to understand human life and to act more intelligently in connection with it; conviction that service to our fellow beings is both a privilege and an obligation; and faith that, while recognizing the importance of nature’s slower way, we may actively further the physical and spiritual wellbeing of mankind.

Whereas heretofore too little has been expected of psychology by most people, now the pendulum has swung in the opposite direction, and hopes as well as demands are extravagant. It is needful, therefore, to emphasize the necessity for patience and temperance. The practical values of psychological methods and of their results depend almost entirely upon the thoroughness, skill, foresight, and disinterestedness with which the science is developed.

VIII

‘Can the value of a man be appraised?’ Man is a delightfully complex and varying object. His values are legion. But even now it is possible to estimate or predict certain of his ‘values’ as a social being by measuring bodily and mental traits. Categorical reply to the question is unsafe, for in certain respects man can be measured accurately. In certain others he cannot, at the present time. Assuredly we cannot to-day appraise a man accurately. But this statement would be grossly misleading if I did not add that substantial progress has been made during the past half-century in the development of methods of measuring man, in our knowledge of his traits and their relations, and, consequently, in our ability to predict his values, or to appraise him.

The preceding paragraph wholly neglects the optimistic note that seems to me legitimate. I beg therefore to declare my faith, and to present my scientific creed. They require few words. Theoretically, man is just as measurable as is a bar of steel or a humanly contrived machine. He is infinitely more complex in constitution, in possibilities of reaction and response, and in relations to environment, than is the bar of steel. But this does not alter measurability. It renders it a more difficult, tedious, and lengthy task, but it also makes it more interesting, for it constantly challenges our faith, persistence, ingenuity, and intellectual resourcefulness. When asked nowadays, ‘Can imaginativeness, skill, courage, honesty, inventiveness, or any similarly and seemingly intangible, unmeasured ability be measured?’ I promptly and dogmatically reply, ‘Yes.’ Then I hasten to qualify my optimistic assertion by explaining that, although convenient and readily usable methods may not be at hand to measure or evaluate the particular aspect of human nature in point, the experienced, skillful, and intelligent psychologist can make the desired observations. It may require weeks or months, but it can be done.

Two decades ago it was possible to measure traits of intellect in psychological laboratories, but impossible to evaluate them simply, accurately, and serviceably, as is done to-day all over the world by means of the so-called ‘intelligence tests.’ We should be sadly lacking in faith, optimism, and the spirit of prophecy, if we refused to maintain the probability that more and more aspects of man will become measurable, more and more modes of response predictable, and more and more social values appraisable.

Can the value of man be accurately appraised? In so far as it depends upon the form of his body, it can be: for height, weight, dimensions of bones, of muscles, cranial capacity, color of skin, hair, eyes, and scores of other aspects of the man as physical object may readily be measured, and the results compared with those obtained from other individuals. Such measurements are the special concern of anthropology. They enable us to identify stages of development, the sexes, different races, and the variety of defects and pathological conditions of the human body.

Anthropometry and physical anthropology have developed through the curiosity of man, but also, and perhaps more, because of the need for accurate knowledge of bodily traits, their changes during growth and occupational use, their relations, their controllability and modifiability by educational means. It has come to be recognized that an essential part of vocational guidance and placement is the attempt to fit the physical man to job or occupation. This requires definite knowledge of occupational requirement, stated in terms of bodily traits, and equally definite knowledge of the traits of a given individual. What has been said of bodily form is equally true of bodily functions. Response to fatigue or to cold or warmth, rapidity and accuracy of movement and coordination, are at once measurable, occupationally significant, and essential conditions of certain ‘values.’

With traits of mind as contrasted with those of body, it is far different. As forms of experience, they appear to be immeasurable, but as expressed in action, behavior, conduct, they can be measured. So it happens that experimental psychology is the application of new and constantly improved ways of testing and measuring what man does under certain circumstances, or in certain situations. Between physiology and psychology it is quite as impossible as unprofitable to attempt to draw a sharp line. Both are interested in bodily processes; but, whereas the physiologist attends chiefly to bodily functions in their relations to structure, the psychologist undertakes to study the relations of certain bodily functions or expressions to sense-impressions, feelings, emotions, ideas, thoughts.

The whole of history is a record of human behavior. Man has always been interested in himself, always observant of his acts. But mostly his descriptions are impressionistic, colored by the purpose or bias of the writer, inaccurate and incomplete. The science of psychology has undertaken to supply carefully controlled and accurate descriptions of behavior, based upon objective measurements of what man actually does in certain definite circumstances. Here is a simple illustration of the contrast between the old and the new descriptions. It has long been recognized that some people respond quickly to sights and sounds, others slowly. The psychologist has devised methods and mechanisms for measuring the time required by a given person to respond to a certain type of stimulus. Results of such measurement may class the individual not merely as quick or slow, but as precisely so quick. His speed of reaction may then be compared with the average for all persons measured, with the quickest or with the slowest, and he can be ranked objectively and precisely. The advantages of such definite objective information over the impressionistic sort are too obvious for comment.

Just as it is possible to measure such a simple characteristic as quickness of response to any sort of stimulus, so likewise the presence of ideas and their use in thinking, the presence of images and their use in remembering or in imagining, may be evaluated by measurements of what a person actually does. Memory — or, rather, memories, for there are several different kinds, which seem to vary independently — is measured by getting reliable records of the amount of material in the shape of words, phrases, sentences, names of objects or acts, which can be recalled under given conditions. For instance,

I repeat to the person to be tested, with uniform emphasis, and at the rate of two per second, the digits 386159427, and the person responds by naming as many as he can in the order in which they were given. Thus, by the use of nine digits, repeated in different orders,

I can readily measure the memory-span of the individual for digits presented auditorially, that is, to the ear. There is a surprising difference among individuals in ability to recall such material. It has also been discovered that a person who can recall only five digits if he merely hears them may be able to recall nine when he sees as well as hears them.

When the psychologist talks about measurements of intelligence, he is inevitably asked if traits of temperament and character, or yet other aspects of personality, can likewise be measured. In the army it was often said that measurement of leadership, reliability, and courage, certainly would be more useful than similarly dependable measures of mental alertness. Although this probably is not true, it is undeniable that the feelings, emotions, and other temperamental characteristics of the person are as important in most practical situations as the intellectual. Occupational fitness depends primarily on bodily, intellectual, and temperamental traits. To appraise the value of a man without trustworthy measurements of his will-power, his reliability, his frankness or honesty, his patience, persistence, or irascibility, his courage or timidity, his self-dependence, his temperamental resourcefulness, his sympathy and self-forgetfulness, would be inexcusably stupid. Bodily traits alone, however accurately measured, are inadequate. Knowledge of intellectual functions constitutes a valuable supplement, but we still fall short of what is required. Knowledge of temperament, which may be defined as the ‘constitutional’ or inborn tendency to feel and act in certain ways, goes far toward completing our picture; but we still have neglected certain components of character and personality which result from the interaction of the above with conditions of life.

It has proved more difficult to measure ‘affective’ — as temperamental traits are called — characteristics, than intellectual. Little progress has been made as yet toward the development of reliable, readily used, and standardized methods of gauging honesty, courage, timidity, and similar essential traits. But starts have been made — starts that have taken the psychologist out of his laboratory into the field of practical life. In connection with criminal procedure, he has been called upon to measure deception; and, although he has not entirely succeeded in this task, he has made sufficient progress to justify optimism. Just as in the case of intellectual functions, he measures, not the experience of the individual, but one or another aspect of behavior or conduct. In a few years we shall be measuring affective traits as readily, as serviceably, and as accurately, as we now measure intellectual functions!

IX

Knowledge is power as truly in the human sphere, intellectual, affective, and social, as in the environmental. Chemistry, and the branch of engineering based upon it, have revolutionized the conditions of human fife. Physics, geology, mineralogy, likewise have found innumerable applications to our welfare. The so-called physical sciences have literally transformed man’s world. Modern medicine — including surgery, preventive medicine, and hygiene—not only has banished the most frightful of the epidemic diseases, or in large measure gained control of them, but has also infinitely increased human comfort, happiness, and efficiency, by discovering the laws of health, and ways of preventing and avoiding disease or defect, and by developing sanitation and personal hygiene as phases of engineering.

For psychology it remains to accomplish in the sphere of behavior and mind what the physical sciences and engineering have accomplished for our physical body and its functions. With increasingly safe and abundant knowledge of man’s mental traits and capacities, we shall intelligently, instead of blindly and by guess, help to fit ourselves and others into the social fabric, help even to change the design of our social system.

Many of the things now viewed as foreordained and, therefore, unapproachable by us, many that are left to chance or accident, we ultimately shall deal with systematically, rationally, and on a basis of safe prediction of reaction and appraisal of values. Vocational and a vocational choices, instead of being left to the wish or whim of parent, guardian, or self, to necessity, or to ease and openness of road, will come more and more to rest on adequate knowledge of the traits and capacities of the self, and on the demands, requirements, and opportunities of different classes of occupation. Job-specifications and descriptions of the individual will become commonplaces of business and social relations.

This vision of the not-remote future of mankind, and of the social order which will result when knowledge of man — physical, mental, and spiritual — is as nearly adequate as is knowledge of his environment to-day, might be elaborated indefinitely. We stand on the threshold of a new era. Mankind, heretofore infantile in his knowledge of himself and in his attitude toward such knowledge and its practical uses, is reflecting on the lessons of history, on the tragedies of ignorance, and on this vision of progress.

May the value of a man be appraised? My confident reply is, ‘Yes.’ If not to-day, to-morrow; for never has there been greater open-mindedness toward knowledge of man and his relations; greater eagerness for more knowledge and for increased ability wisely to direct and shape his individual and social life, than at present. To-day many things are possible to us which seemed unapproachable a generation ago. Evidently the part of wisdom is to be open-minded, optimistic, determined in our search for knowledge, and equally so in our use of it. We may not assume that we are wise enough safely to direct ourselves or our social order; but, nevertheless, we must admit that we are responsible for the conduct of our own lives, and for the social order, with all its imperfections.