Special talents and defects

I. SPECIAL FUNCTIONS WHICH HAVE NOT BEEN LONG STUDIED

There are various mental functions which are now thought to be largely special, which have not yet been studied sufficiently to warrant extended discussion of each, yet which merit notice as such if for no other reason than that attention should be directed to the desirability of studying their place in intellectual organization. Some of these, like chess-playing, will not be discussed here, as they are at present but remotely connected with prescribed education. We shall, therefore, comment upon but some of these, giving such facts and theories as are available in the case of each.

II. LEFT-HANDEDNESS

The hand is rated by students of the history of civilization as one of the most important determinants of man’s rise from savagery. The loss of even a finger is a handicap recognized in such times of stress, as when men are drafted for war. With the great majority of people, the two hands are unequal in strength and accuracy, the right being the major member. With a small minority of children there is, however, a predisposition to use the left hand, instead of the right hand, as the major member. This is a special condition which must be taken into account by educators.

According to different investigators, the proportion of left-handed children ranges from 2 to 6 per cent. The disagreements arise from the variety of criteria used and of populations sampled. The median figure of 4 per cent seems, for several reasons most probable, as the general proportion of left-handedness.

Many theories as to the origin of handedness have been formulated. It has been argued that handedness is not innate, but acquired from the mother’s habitual method of carrying the infant on one arm rather than on the other, so that one of its arms is pinioned against the mother habitually, and gets comparatively little exercise. The theory has been advanced that since the heart is the most vital organ of the body, and is located on the left side, the shield to protect it was held by the left hand, permitting the right hand to attain greater dexterity with the spear, the advantage thus acquired being transmitted to offspring. Also, it has been proposed that the center of gravity of the viscera, the position of the subclavian arteries, cerebral asymmetry, and greater blood supply to one cerebral hemisphere may be, respectively, the origin of handedness. All of these theories are unsatisfactory, for reasons which have been well stated by the original investigators. There remains to be considered the proposal that handedness is determined by ocular dominance. The right eye is the better seeing eye in about 96 per cent of people. As vision develops long before muscular coördination in the infant, the proposal is that the hand is brought to coöperate with the dominant eye. The disproof of this theory is that among the congenitally blind the proportion of right-handed to left-handed is not materially different from that among seeing persons.

The origin of handedness is, therefore, not understood, and it is not known why about 4 per cent of the population should show dominance of the left hand. It must be considered that handedness is of many degrees, from extreme right-handedness, through ambidexterity, to extreme left-handedness. All right-handed persons are not equally right-handed, and all left-handed persons are not equally left-handed.

Trustworthy studies of the heredity of handedness indicate that it is inherited. Ramaley studied 610 parents and 1130 children, and arrived at the conclusion that left-handedness is inherited (as a Mendelian recessive), and is potential in about one-sixth of the population.

It is obvious that modern appliances are adapted to the right-handed, and that right-handedness is regarded generally as “the way to be.” Teachers and parents feel it their duty to compel the child to use the right hand.

Studies of left-handed children who have been “changed over” through education or accident to the right hand, and of right-handed children changed over through accident to the left hand, lead to the conclusion that among them there is more nervousness and a greater number of speech defects than would be allowed by the usual course of events. Stammering is evidently a complication in some cases of modified handedness. The physiology of this connection is obscure. In view of the fact that speech defects occur to so great an extent in “changing over,” and that we do not know the physiology of handedness, it seems by all means wisest not to try to modify handedness where it is very pronounced. A very right-handed person, fortunate in being with the majority, may, by using for a week his left hand instead of his right, get an idea of what is suffered by a very left-handed child being compelled to use the right hand.

It has been reported that there is an undue proportion of left-handed persons among criminals, mental defectives, and the insane. These reports require careful verification. Criminals, mental defectives, and the insane have been much more carefully scrutinized than have the superior in intellect and character, or even than the average population. The present writer has, during recent surveys, noticed left-handed performance repeatedly in very gifted children, but has not computed the proportion. Until further scrutinies have been made, it cannot be said positively that left-handedness is correlated with organic inferiority.

Perfectly satisfactory tests of handedness have not yet been agreed upon. Jones proposed some years ago to measure congenital handedness by means of a brachiometer. This is an instrument for measuring the bones of the forearm, and by its use Jones hoped to detect handedness “at the moment of birth” as well as on any subsequent day of life. These hopes have not been realized in the findings of others who have given the method fair trial, as Beeley did. Tapping, with the wrist movement, tapping with fingers, tracing, spontaneous rubbing, throwing and picking up, winding, and cutting with scissors are the most promising among tests so far tried out, to discover whether a child is congenitally left-handed. Gripping, as with the dynamometer, does not seem to correlate so well with known facts, as do the other tests of movement.

Left-handedness as an element in individuality becomes conspicuous in school procedure especially in writing, drawing, shop work, or any work where the hand is an important factor in the performance. It may become conspicuous in vocational endeavor, either as an asset or a handicap. In a few kinds of performance, such as baseball or tennis, left-handedness gives an advantage, all other things being equal. In most professional pursuits (with the possible exception of dentistry and surgery because of manufactured appliances) left-handedness is a matter of indifference. In work with machines left-handedness is likely to be a handicap, because machines are “right-handed.” Even scissors, eggbeaters, typewriters, and other common appliances of office and home are “right-handed.”

Left-handedness as a handicap in the absence of rational consideration of it, is illustrated in an extreme fashion by the case of a young pickpocket, remanded for mental examination upon second offense. This boy was of average general intelligence, extremely left-handed, and a stammerer. He had left school as soon as the law allowed, with a record of chronic truancy behind him. He explained that he had always “hated school,” because the teachers tried to make him right-handed, and because he was so ashamed of his stammering. Obtaining his working papers, he had first tried factory work, but the machines were all right-handed. He had then taken “a job” as an office boy, but he had to abandon that because he could not adequately answer the telephone, or converse with those who questioned him. Being “fired,” he found a place as packer of china in a department store, but had a fight with a fellow worker, who mimicked him, and was dismissed. Soon thereafter, needing money, he saw an opportunity to abstract a purse from a convenient pocket, and did so. The success of this venture led to others like it, until he was apprehended and sent to the reformatory. Having served his time, he came out with this record added to his original difficulties, and drifted again into picking pockets.

The history of this boy shows the adaptation to social environment of an organism struggling by trial and error methods, without rational guidance. A left-handed man can pick pockets as well as anyone else (perhaps better), and speech defect is here no hindrance, since perfect silence is observed in such pursuits.

This boy might have had a very different career if school and society had given a different kind of consideration to his individuality.

III. MIRROR WRITING

A certain number of children, variously estimated, write backwards, beginning at the right of the page. This is called “mirror writing,” and is apparently a function of left-handedness. Baldwin’s description is succinct.

“Mirror writing is the form of inscription which arises from tracing words with the left hand by an exact reduplication of the movements of the right hand, in a symmetrical way from the central point in front of the body, out toward the left. It produces a form of reversed writing which cannot be read until it is seen in a mirror. Many left-handed children tend to write in this way. Some adults, on taking a pen to write with the left hand, find they can write only in this way. Even those, like myself, to whom the movements seem, when thought of in visual terms, quite confusing and impossible, yet find when they try to write with both hands together, in the air, from a central point right and left, that the left hand mirror writing movements are very natural and easy.”

Beeley conducted a survey, by questionnaire addressed to teachers, of the prevalence of mirror writers in the elementary schools of Chicago. He thus found one mirror writer to every 2500 children. Gordon by actual tests of writing found a larger proportion of mirror writers, about one-half of one per cent. Among feeble-minded children in special schools the percentage appears to be much greater, in fact, about seventeen times as great, according to Gordon’s findings.

All investigators agree that mirror writers are almost always left-handed by test, though the writing may be done with the left hand, or with the right. As to the hand used in producing the writing there is disagreement among investigators. Gordon found that “the mirror writers were nearly always left-handed children who wrote with the right hand.” Beeley says: “All of the mirror writers write mirror-wise with the left hand. The only instances of right-hand mirror writing found were a few upper-grade pupils who having seen this kind of writing naturally executed by mirror writers, attempted to imitate the same.”

The origin of mirror writing is not fully explained as yet. It is probably the natural mode for left-handed persons, as attempts to write with both hands indicate. Yet not all left-handed persons acquire this habit. Obviously the mirror writer is not corrected in his fault by notice of the discrepancies between the visual and the motor. It may be that those left-handed children who become mirror writers are usually deficient in visual perception of letters or words, or generally deficient. That there are, however, bright children who form this habit is shown by the surveys made.

Samples of mirror writing by school children are shown in Figure 27. In order to correct the difficulty, visual control of movement must be cultivated. Attempts to correct by changing over to the right hand are injudicious, for the reasons cited under the discussion of left-handedness.

In securing the control of visual perception and imagery, it is well to have the child write slowly and carefully from a copy, not being allowed for some time to write spontaneously. At first, particularly, the teacher may guide the child’s hands and urge him to notice in detail how another writes. Of course, the best educational treatment is that which never permits the development of the habit in the first place. This could be accomplished by careful watching of all left-handed children, at the very beginning of their attempts to learn to write. As each letter and figure is taught for the first time, the child whose natural impulse is to reverse it could be made conscious of his error, and could be drilled in the coördinations of hand and eye which produce the correct response. In the very large beginners’ classes which are customary in the public schools, such careful attention to the needs of individuals is here, as in other respects, difficult to give.

IV. MECHANICAL ABILITY

In 1915 Stenquist, Thorndike, and Trabue, working with dependent children in a county of New York State, used tests of various mental functions, including a test of ability to put simple mechanisms together. These correlations showed that whereas tests of ability to handle language and tests of general intelligence (Binet-Simon) gave positive coefficients as high as .90, the test of mechanical ability yielded a coefficient much lower, when correlated with these. They therefore suggested that mechanical ingenuity might be a relatively specialized form of capacity, not reliably predictable from knowledge of general intelligence.

Subsequently, one of these investigators, Stenquist, made extended tests, and standardized a measuring scale to gauge mechanical ability. Measuring individuals for general intelligence and for mechanical ability, a positive coefficient of correlation amounting to about .40 is ordinarily obtained. This relationship is obviously not close. Ability to put mechanisms together is not reliably predictable from status in general intelligence. The chances are, however, that a pupil who is superior in general intelligence will score higher in mechanical ability, than a generally stupid pupil will score. There is no negative or compensatory relation between the two functions, as is sometimes assumed.

Wider studies, including tests of learning mechanical processes, will give further light upon the extent to which ability to deal with concrete mechanisms coheres with general intelligence, and to what extent comprehension of mechanical principles is so correlated. It may be that the correlation between performances in Stenquist’s tests and in tests like those used to measure general intelligence is reduced through factors like selective attention operating over a period of years. It may be that the relatively unintelligent become relatively more proficient in concrete acts, like assembling a bicycle bell or putting a lock together, because they have not the degree of intelligence that would enable them to prefer reading as an activity. Thus when 40 fifteen-year-old boys, 20 of whom have IQ’s (Stanford-Binet) from 150 to 170, and 20 of whom have IQ’s from 90 to 100, are faced with a series of tasks similar to those mentioned above, those of lower IQ might conceivably produce a record equal to or surpassing that of the first group, because their ability had enabled them to practice only tasks at a comparatively low level of general capacity. With an equal amount of attention to these matters, not previously of much interest to them, the boys of 150 to 170 IQ might surpass their competitors greatly. In a test of cake-baking, a hundred housewives, selected at random on a given date, will surpass the hundred most eminent men of science; but not after both groups have attended to the matter for an equal length of time.

The tests of mechanical ability do not as yet eliminate the influence of mechanical interest upon the outcome of the test. Extremely high intelligence may well be relatively little interested in concrete materials and processes, preferring to manipulate ideas. Thus on a given date lower intelligence, long acting on that level, may surpass. Yet the higher IQ may really be capable under incentive, of surpassing in work with things as well as in work with ideas. Tests of learning mechanical processes would, therefore, be a most valuable supplement to what has already been done in this field.

Great inventors of mechanical devices are probably, as a group, very far above the average in general intelligence. This statement cannot be made with positive certainty, as the general intelligence of a large number of inventors has never been measured. It rests only on deduction from the fact that invention evidently calls for a high degree of selective thinking, and of interest in problem situations. Even “invention by accident” which may occasionally occur, calls for a high degree of ability to “notice” a new element in the familiar situation, in relation to other elements.

V. ABILITY TO LEAD AND HANDLE PEOPLE

It has been suggested that executive ability, in the sense of ability to deal effectively with human relationships, is specialized; that it is not closely correlated with IQ. Very few quantitative studies of the matter have been undertaken, largely because of the lack of means to gauge objectively “ability to handle people.” It is true that there exist persons whose ability to deal effectively with human relationships has stood the test of life—executives in professional bodies, in business, and in government. These persons have not, however, been subjected to mental examination. Their time is so valuable that investigators perhaps hesitate to encroach upon it. Even if this could be done, we should nevertheless lack proper data for correlational study. We should also need to know how many persons of an equal degree of intelligence had failed to succeed as executives. This would be difficult to discover.

Terman has given us a few facts, from his studies of superior children, which tend to indicate the relation between leadership and intelligence, in childhood. According to teachers’ judgments of leadership, children of over 120 IQ are much oftener leaders than children of less intelligence are, and they are usually well liked by other children, even when not designated as leaders. Very few children over 120 IQ are judged by teachers to be “unpopular.”

From observations of the frequency with which children of high IQ are leaders of other children, the present writer suspects that there is an optimum range of IQ, within which popular leadership is extremely frequent, but above which it is very improbable. The optimum range for leadership appears to fall between 110 and 130, when the total group has a median IQ of 100. Children of IQ over 160 seem to have little chance of leading their fellow children, when the median IQ of the group is 100. Children of IQ over 180 have almost no chance, in the observations of the present writer, to be popular leaders. Of the four New York children, previously mentioned in other chapters, measuring over 180 IQ (Stanford-Binet), only one is an organizer of fellow children, being designated by her teachers as “the most popular child in the school.” This child functions as leader of a group of highly selected children, with a median IQ of near 120. In a group of unselected children she probably could not achieve leadership, although highly endowed with physical and temperamental traits which favor leadership.

Why should too much intelligence militate against the achievement of popular leadership? It is clear that in order to organize and lead others, the individual must comprehend and share the interests of those led, and must in turn be understood by them. He must not consider their pursuits to be fatuous and without substance. They must not regard his interests as eccentric and unfathomable. Also, he must not experience too keenly the impact of the conflicting conations of those about him. To perceive and to experience too sharply the disappointments, misdeeds, punishments, and aspirations of others tend to disqualify for executive leadership.

The child of IQ over 160 tends to fall above the optimum range for leadership, for all of these reasons, in groups of unselected children. He is not interested in mumble-the-peg. They are not interested in the solar system. His interests are those of persons far beyond his age and size. But they will not accept his leadership because he does not “look like” a fitting captain for them. Thus only in very highly selected groups can such a child achieve leadership, that is, in groups which approximate his own IQ.

Too much intelligence thus tends to disqualify for executive leadership. The most intelligent persons born will usually be found leading only highly selected groups. Too little intelligence also undoubtedly tends to disqualify. It will be a nice problem to determine experimentally just what may be the optimum range of IQ for leadership of typical persons. Correlation is, of course, reduced by the various influences which we have been discussing. “Social intelligence” is in all probability not a specialized capacity, but merely an optimum section of the general intelligence curve (determined by ratio to the median intelligence of the led), combined with certain amounts of physical and temperamental traits.

These temperamental and physical traits are extremely important. The flighty, the unenthusiastic, the shy, the overbearing, the ungenerous, the irritable are not well fitted to organize and lead, even when their intelligence is optimum. Likewise, the small, the commonplace in coloring, the undistinguished in features, the ill-kempt, the shrill of voice, are handicapped by their physical characteristics. The executive leader is he who combines optimum intelligence with enthusiasm, generosity, cheerfulness, and other favorable temperamental traits in the optimum degree, and who is large, forceful in manner and voice, and distinguished in contour and coloring. Facility in handling people and getting their allegiance, is due, therefore, to total personality, mental and physical, of which intellect is but one determinant. Correlations between executive ability and general intelligence will thus be greatly reduced from unity, because temperament and physique are far from perfectly correlated with general intelligence.

REFERENCES

Beeley, A. L.—An Experimental Study of Left-Handedness; University of Chicago Press, 1918.

Downey, J. E.—“On the Reading and Writing of Mirror Script”; Psychological Review, 1914.

Gordon, H.—“Left-Handedness and Mirror Writing, Especially among Defective Children”; Brain, 1921.

Gowin, E. B.—The Executive and His Control of Men; The Macmillan Co., New York, 1915.

Stenquist, J. L.—Stenquist Assembling Tests of General Mechanical Ability; Board of Education, New York, 1921.

Taussig, F. W.—Inventors and Money Makers; The Macmillan Co., New York, 1895.

Thorndike, E. L.—“Intelligence and Its Uses”; Harper’s Magazine, 1920.