MISCELLANEOUS
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.
[Illustration:
FIG. 27.—Showing mirror writing by public school pupils. (From
Beeley’s _An Experimental Study of Left-Handedness_. Reproduced by
courtesy of the University of Chicago Press.)
]
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.