The Measurement of Intelligence Part 41

(c) _Difficulty of hitting a distant mark_

PROCEDURE. Say to the subject: "_You know, do you not, what it means when they say a gun 'carries 100 yards'? It means that the bullet goes that far before it drops to amount to anything._" All boys and most girls more than a dozen years old understand this readily. If the subject does not understand, we explain again what it means for a gun "to carry" a given distance. When this part is clear, we proceed as follows: "_Now, suppose a man is shooting at a mark about the size of a quart can. His rifle carries perfectly more than 100 yards. With such a gun is it any harder to hit the mark at 100 yards than it is at 50 yards?_" After the response is given, we ask the subject to explain.

SCORING. Simply to say that it would be easier at 50 yards is not sufficient, nor can we pa.s.s the response which merely states that it is "easier to aim" at 50 yards. The correct principle must be given, one which shows the subject has appreciated the fact that a small deviation from the "bull's-eye" at 50 yards, due to incorrect aim, becomes a larger deviation at 100 yards. However, the subject is not required to know that the deviation at 100 yards is exactly twice as great as at 50 yards. A certain amount of questioning is often necessary before we can decide whether the subject has the correct principle in mind.

SCORING THE ENTIRE TEST. _Two of the three problems_ must be solved in such a way as to satisfy the requirements above set forth.

REMARKS. These problems were devised by the writer. They yield interesting results, when properly given, but are not without their faults. Sometimes a very superior subject fails, while occasionally an inferior subject unexpectedly succeeds. On the whole, however the test correlates fairly well with mental age. At the 14-year level less than 50 per cent pa.s.s; of "average adults," from 60 to 75 per cent are successful. Few "superior adults" fail.

The test as here given is little influenced by the formal instruction given in the grades or the high school. In fact, 80 per cent of our uneducated business men, as contrasted with 65 per cent of high-school juniors and seniors, pa.s.sed the test. Success probably depends in the main upon previous interest in physical relationships and upon the ability to understand phenomena of this kind which the subject has had opportunity to observe.

It would be interesting to standardize a longer series of problems designed to test a subject's comprehension of common physical relationships. In the first few months of life a normal child learns that objects unsupported fall to the ground. Later he learns that fire burns; that birds fly in the air; that fish do not sink in the water; that water does not run uphill; that it is easy to lift a leg or arm as one lies p.r.o.ne in the water; that mud is thrown from a rotating wheel (and always in the same direction); that a stone which is flying through the air swiftly is more dangerous than one which is moving slowly; that it is more dangerous to be run over by a train than by a buggy; that it is hard to run against a strong wind; that cyclones blow down trees and houses; that a rapidly moving train creates a stronger wind than a slower train; that a feather falls through the air with less speed than a stone; that a falling object gains momentum; that a heavy moving object is harder to stop than a light object moving at the same rate; that freezing water bursts pipes; that sounds sometimes give echoes; that rainbows cannot be approached; that a lamp seems dim by daylight; that by day the stars are not visible and the moon only barely visible; that the headlights of an approaching automobile or train are blinding; that if the room in which we are reading is badly lighted we must hold the book nearer to the eyes; that running makes the heart beat faster and increases the rate of breathing; that if we are cold we can get warm by running; that whirling rapidly makes us dizzy; that heat or exercise will cause perspiration, etc.

Although the causes of some of these phenomena are not understood even by intelligent adults without some instruction, the facts themselves are learned by the normal individual from his own experience. The higher the mental level and the greater the curiosity, the more observant one is about such matters and the more one learns. Many items of knowledge such as we have mentioned could and should be standardized for various mental levels. In devising tests of this kind we should, of course, have to look out for the influences of formal instruction.

CHAPTER XX

INSTRUCTIONS FOR "SUPERIOR ADULT"

SUPERIOR ADULT, 1: VOCABULARY (SEVENTY-FIVE DEFINITIONS, 13,500 WORDS)

PROCEDURE and SCORING, as in previous vocabulary tests. At the "superior adult" level seventy-five words should be known.

The test is pa.s.sed by only one third of those at the "average adult"

level, but by about 90 per cent of "superior adults." Ability to pa.s.s the test is relatively independent of the number of years the subject has attended school, our business men showing even a higher percentage of pa.s.ses than high-school pupils.

SUPERIOR ADULT, 2: BINET'S PAPER-CUTTING TEST

PROCEDURE. Take a piece of paper about six inches square and say: "_Watch carefully what I do. See, I fold the paper this way_ (folding it once over in the middle), _then I fold it this way_ (folding it again in the middle, but at right angles to the first fold). _Now, I will cut out a notch right here_" (indicating). At this point take scissors and cut out a small notch from the middle of the side which presents but one edge. Throw the fragment which has been cut out into the waste-basket or under the table. Leave the folded paper exposed to view, but pressed flat against the table. Then give the subject a pencil and a second sheet of paper like the one already used and say: "_Take this piece of paper and make a drawing to show how the other sheet of paper would look if it were unfolded. Draw lines to show the creases in the paper and show what results from the cutting._"

The subject is not permitted to fold the second sheet, but must solve the problem by the imagination unaided.

Note that we do not say, "_Draw the holes_," as this would inform the subject that more than one hole is expected.

SCORING. The test is pa.s.sed _if the creases in the paper are properly represented, if the holes are drawn in the correct number, and if they are located correctly_, that is, both on the same crease and each about halfway between the center of the paper and the side. The shape of the holes is disregarded.

Failure may be due to error as regards the creases or the number and location of the holes, or it may involve any combination of the above errors.

REMARKS. Success seems to depend upon constructive visual imagination.

The subject must first be able to construct in imagination the creases which result from the folding, and secondly, to picture the effects of the cutting as regards number of holes and their location. It appears that a solution is seldom arrived at, even in the case of college students, by logical mathematical thinking. Our unschooled subjects even succeeded somewhat better than high-school and college students of the same mental level.

Binet placed this test in year XIII of the 1908 scale, but shifted it to the adult group in the 1911 revision. G.o.ddard retains it in the adult group, while Kuhlmann places it in year XV. There have also been certain variations in the procedure employed. As given in the Stanford revision the test is pa.s.sed by hardly any subjects below the 14-year level, but by about one third of "average adults" and by the large majority of "superior adults."

SUPERIOR ADULT, 3: REPEATING EIGHT DIGITS

PROCEDURE and SCORING, the same as in previous tests with digits reversed. The series used are: 7-2-5-3-4-8-9-6; 4-9-8-5-3-7-6-2; and 8-3-7-9-5-4-8-2.

Guard against rhythm and grouping in reading the digits and do not give warning as to the number to be given.

The test is pa.s.sed by about one third of "average adults" and by over two thirds of "superior adults." The test shows no marked difference between educated and uneducated subjects of the same mental level.

SUPERIOR ADULT, 4: REPEATING THOUGHT OF Pa.s.sAGE

PROCEDURE. Say: "_I am going to read a little selection of about six or eight lines. When I am through I will ask you to repeat as much of it as you can. It doesn't make any difference whether you remember the exact words or not, but you must listen carefully so that you can tell me everything it says._" Then read the following selections, pausing after each for the subject's report, which should be recorded _verbatim_:--

(a) "_Tests such as we are now making are of value both for the advancement of science and for the information of the person who is tested. It is important for science to learn how people differ and on what factors these differences depend. If we can separate the influence of heredity from the influence of environment, we may be able to apply our knowledge so as to guide human development. We may thus in some cases correct defects and develop abilities which we might otherwise neglect._"

(b) "_Many opinions have been given on the value of life. Some call it good, others call it bad. It would be nearer correct to say that it is mediocre; for on the one hand, our happiness is never as great as we should like, and on the other hand, our misfortunes are never as great as our enemies would wish for us. It is this mediocrity of life which prevents it from being radically unjust._"

Sometimes the subject hesitates to begin, thinking, in spite of our wording of the instructions, that a perfect reproduction is expected.

Others fall into the opposite misunderstanding and think that they are prohibited from using the words of the text and must give the thought entirely in their own language. In cases of hesitation we should urge the subject a little and remind him that he is to express the thought of the selection in whatever way he prefers; that the main thing is to tell what the selection says.

SCORING. The test is pa.s.sed if the subject is able to repeat in reasonably consecutive order the main thoughts of at least one of the selections. Neither elegance of expression nor _verbatim_ repet.i.tion is expected. We merely want to know whether the leading thoughts in the selection have been grasped and remembered.

All grades of accuracy are found, both in the comprehension of the selection and in the recall, and it is not always easy to draw the line between satisfactory and unsatisfactory responses. The following sample performances will serve as a guide:--

_Selection (a)_

_Satisfactory._ "The tests which we are making are given for the advancement of science and for the information of the person tested. By scientific means we will be able to separate characteristics derived from heredity and environment and to treat each cla.s.s separately. By doing so we can more accurately correct defects."

"Tests like these are for two purposes. First to develop a science, and second to apply it to the person to help him. The tests are to find out how you differ from another and to measure the difference between your heredity and environment."

"These tests are given to see if we can separate heredity and environment and to see if we can find out how one person differs from another. We can then correct these differences and teach people more effectively."

"The tests that we are now making are valuable along both scientific and personal lines. By using them it can be found out where a person is weak and where he is strong. We can then strengthen his weak points and remedy some things that would otherwise be neglected. They are of great benefit to science and to the person concerned."

"Tests such as we are now making are of great importance because they aim to show in what respects we differ from others and why, and if they do this they will be able to guide us into the right channel and bring success instead of failure."

_Unsatisfactory._ "Tests such as we are now making are of value both for the advancement of science and for the information of the person interested. It is necessary to know this."

"Such tests as we are now making show about the human mind and show in what channels we are fitted. It is the testing of each individual between his effects of inheritancy and environment."

"It is very interesting for us to study science for two reasons; first, to test our mental ability, and second for the further development of science."

"Tests such as we are now making help in two ways; it helps the scientists and it gives information to the people."

"Tests are being given to pupils to-day to better them and to aid science for generations to come. If each person knows exactly his own beliefs and ideas and faults he can find out exactly what kind of work he is fitted for by heredity. The tests show that environment doesn't count, for if you are all right you will get along anyway." (Note invention.)

_Selection (b)_

_Satisfactory._ "There are different opinions about life. Some call it good and some bad. It would be more correct to say that it is middling, because we are never as happy as we would like to be and we are never as sad as our enemies want us to be."