Record the response, and, showing another box, say: "_This box has two smaller boxes inside, and each of the smaller boxes contains two tiny boxes. How many altogether? Remember, first the large box, then two smaller ones, and each smaller one contains two tiny boxes._"
The third problem, which is given in the same way, states that there are _three_ smaller boxes, each of which contains _three_ tiny boxes.
In the fourth problem there are _four_ smaller boxes, each containing _four_ tiny boxes.
The problem must be given orally, and the solution must be found without the aid of pencil or paper. Only one half-minute is allowed for each problem. Note that each problem is stated twice.
A correction is permitted, provided it is offered spontaneously and does not seem to be the result of guessing. Guessing can be checked up by asking the subject to explain the solution.
SCORING. _Three of the four_ problems must be solved correctly within the half-minute allotted to each.
REMARKS. Success depends, in the first place, upon ability to comprehend the statement of the problem and to hold its conditions in mind.
Subjects much below the 12-year level of intelligence are often unable to do this.
Granting that the problem has been comprehended, success seems to depend chiefly upon the facility with which the constructive imagination manipulates concrete visual imagery. In this respect it resembles the problem of reversing the hands of a clock. With some subjects, however, verbal imagery alone is operative. Tactual imagery would, of course, serve the purpose as well.
This is as good a place as any to emphasize the fact that the introspective study of mental imagery has little to contribute to the measurement of intelligence. Intelligence tests are concerned with the total result of a thought process, rather than with the imagery supports of that process. Thought may be carried on almost equally well by various kinds of imagery. As Galton showed, a person can be taught to carry on arithmetical processes by the use of smell imagery. The kind of imagery employed is the product of slight, innate preferences complicated by the more or less accidental effects of habit.
We may say that imagery is to thinking what scaffolding is to architecture. The important thing is the completed building rather than the nature of the scaffolding employed in erecting it. No one thinks of blaming the ill construction of a building upon the kind of scaffolding used, for if the architect and builder are competent satisfactory scaffolding will be found. Just as little are deficiencies or peculiarities of imagery the real cause of low-order intelligence. We cannot increase intelligence by formal drill in the use of supposedly important kinds of mental imagery, any more than we can transform a plain carpenter into a Michael Angelo by instructing him in the use of scaffolding materials such as were employed in the construction of St.
Peter"s Cathedral.
This test is of our own invention and has been brought to its present form only after a good deal of preliminary experimentation. It correlates fairly well with mental age as determined by the scale as a whole. It was pa.s.sed by 55 per cent of high-school pupils and by 65 per cent of unschooled business men. Success in it is thus seen not to depend upon schooling.
AVERAGE ADULT, 5: REPEATING SIX DIGITS REVERSED
The series used are: 4-7-1-9-5-2; 5-8-3-2-9-4; and 7-5-2-6-3-8.
PROCEDURE and SCORING, as in year VII, alternative 2.
REMARKS. The test is pa.s.sed by approximately half of "average adults"
and by three fourths of "superior adults." It shows no effect of schooling, the uneducated business men even surpa.s.sing our high-school students.
For the higher levels of intelligence, especially, the test is superior to that of repeating digits in the direct order. It is less mechanical and makes heavier demands upon higher intelligence.
AVERAGE ADULT, 6: USING A CODE
PROCEDURE. Show the subject the code given on the accompanying form.
Say: "_See these diagrams here. Look and you will see that they contain all the letters of the alphabet. Now, examine the arrangement of the letters. They go_ (pointing) _a b c, d e f, g h i, j k l, m n o, p q r, s t u v, w x y z. You see the letters in the first two diagrams are arranged in the up-and-down order_ (pointing again), _and the letters in the other two diagrams run in just the opposite way from the hands of a clock_ (pointing). _Look again and you will see that the second diagram is drawn just like the first, except that each letter has a dot with it, and that the last diagram is like the third except that here, also, each letter has a dot. Now, all of this represents a code; that is, a secret language. It is a real code, one that was used in the Civil War for sending secret messages. This is the way it works: we draw the lines which hold a letter, but leave out the letter. Here, for example, is the way we would write "spy?"_" Then write the word _spy_, pointing out carefully where each letter comes from, and emphasizing the fact that the dot must be used in addition to the lines in writing any letter in the second or the fourth diagram. Ill.u.s.trate also with _war_.
Then add: "_I am going to have you write something for me; remember now, how the letters go, first_ (pointing, as before) _a b c, d e f, g h i, then j k l, m n o, p q r, then s t u v, then w x y z. And don"t forget the dots for the letters in this diagram and this one_" (pointing). At this point, take away the diagrams and tell the subject to write the words _come quickly_. Say nothing about hurrying.
The subject is given a pencil, but is allowed to draw only the symbols for the words _come quickly_. He is not permitted to reproduce the entire code and then to copy the code letters from his reproduction.
SCORING. The test is pa.s.sed if the words are written in _six minutes and without more than two errors_. Omission of a dot counts as only a half error.
REMARKS. It is not easy to a.n.a.lyze the mental functions which contribute to success in the code test. Contrary to what might be supposed, success does not necessarily depend upon getting and retaining a visual picture of the diagrams. Kinaesthetic imagery will answer the purpose just as well, or the original visual impression may even be translated at once into auditory-verbal imagery and remembered as such. The significance of the test must be expressed in other terms than the kind of imagery it may happen to bring into play.
Healy and Fernald describe the task of writing a code sentence without copy as one which requires "close attention and steadiness of purpose."
They also emphasize the fact that the attention must be directed inward, since there is no object of interest before the senses and since no special stimulus to attention is offered by the experimenter.
Observations we have made on subjects during the test confirm this view as to the factors involved.
That inability to remember the code as a whole is not a common cause of failure is shown by the fact that subjects above 12-year intelligence who have failed on the test are nearly always able to reproduce the diagrams and insert the letters in their proper places. To give the code form of a given letter without copy, however, makes a much heavier demand on attention. Nearly all subjects find it necessary to trace the code form, in imagination, from the beginning up to each letter whose code form is sought. Subjects of superior intelligence, however, sometimes. .h.i.t upon the device of remembering the position of the individual key letters e.g. (the first letter of each figure) from which, as a base, any desired letter form may be quickly sought out.
The test correlates well with mental age, but for some reason not apparent it is pa.s.sed by a larger percentage of high-school pupils than unschooled adults of the same mental level.
The code test was first described by Healy and Fernald in their "Tests for Practical Mental Cla.s.sification."[77] The authors gave no data, however, which would indicate the mental level to which the test belongs. Dr. G.o.ddard incorporated it in year XV of his revision of the Binet scale, but also fails to give statistics. The location given the test in the Stanford revision is based on tests of nearly 500 individuals ranging from a mental level of 12 years to that of "superior adult." It appears that the test is considerably more difficult than most had thought it to be.
[77] _Psychological Review Monographs_ (1911), vol. XIII, no. 2, p. 51.
AVERAGE ADULT, ALTERNATIVE TEST 1: REPEATING TWENTY-EIGHT SYLLABLES
The sentences for this test are:--
(a) _Walter likes very much to go on visits to his grandmother, because she always tells him many funny stories._ (b) _Yesterday I saw a pretty little dog in the street. It had curly brown hair, short legs, and a long tail._
PROCEDURE. Exactly as in VI, 6. Emphasize that the sentence must be repeated without a single change of any sort. Get attention before giving each sentence.
SCORING. Pa.s.sed _if one sentence is repeated without a single error_. In VI and X we scored the response as satisfactory if one sentence was repeated without error, or if two were repeated with not more than one error each.
REMARKS. The test of repeating sentences is not as satisfactory in the higher intelligence levels as in the lower. It is too mechanical to tax very heavily the higher thought processes. It does, however, have a certain correlation with intelligence. Contrary to what one would have expected, uneducated adults of "average adult" intelligence surpa.s.sed our high-school students of the same mental level.
Binet located this test in year XII of the 1908 series, but shifted it to year XV in 1911. The American versions of the Binet scale have usually retained it in year XII, though G.o.ddard admits that the sentences are somewhat too difficult for that year. Kuhlmann puts the test in year XII, but reduces the sentences to twenty-four syllables and permits one re-reading. We give only two trials and our sentences are considerably more difficult. With the procedure and scoring we have used, the test is rather easy for the "average adult" group, but a little too hard for year XIV.
AVERAGE ADULT, ALTERNATIVE TEST 2: COMPREHENSION OF PHYSICAL RELATIONS
(a) _Problem regarding the path of a cannon ball_
PROCEDURE. Draw on a piece of paper a horizontal line six or eight inches long. Above it, an inch or two, draw a short horizontal line about an inch long and parallel to the first. Tell the subject that the long line represents the perfectly level ground of a field, and that the short line represents a cannon. Explain that the cannon is "_pointed horizontally (on a level) and is fired across this perfectly level field_." After it is clear that these conditions of the problem are comprehended, we add: "_Now, suppose that this cannon is fired off and that the ball comes to the ground at this point here_ (pointing to the farther end of the line which represents the field). _Take this pencil and draw a line which will show what path the cannon ball will take from the time it leaves the mouth of the cannon till it strikes the ground._"
SCORING. There are four types of response: (1) A straight diagonal line is drawn from the cannon"s mouth to the point where the ball strikes.
(2) A straight line is drawn from the cannon"s mouth running horizontally until almost directly over the goal, at which point the line drops almost or quite vertically. (3) The path from the cannon"s mouth first rises considerably from the horizontal, at an angle perhaps of between ten to forty-five degrees, and finally describes a gradual curve downward to the goal. (4) The line begins almost on a level and drops more rapidly toward the end of its course.
Only the last is satisfactory. Of course, nothing like a mathematically accurate solution of the problem is expected. It is sufficient if the response belongs to the fourth type above instead of being absurd, as the other types described are. Any one who has ever thrown stones should have the data for such an approximate solution. Not a day of schooling is necessary.
(b) _Problem as to the weight of a fish in water_
PROCEDURE. Say to the subject: "_You know, of course, that water holds up a fish that is placed in it. Well, here is a problem. Suppose we have a bucket which is partly full of water. We place the bucket on the scales and find that with the water in it it weighs exactly 45 pounds.
Then we put a 5-pound fish into the bucket of water. Now, what will the whole thing weigh?_"
SCORING. Many subjects even as low as 9- or 10-year intelligence will answer promptly, "Why, 45 pounds and 5 pounds makes 50 pounds, of course." But this is not sufficient. We proceed to ask, with serious demeanor: "_How can this be correct, since the water itself holds up the fish?_" The young subject who has answered so glibly now laughs sheepishly and apologizes for his error, saying that he answered without thinking, etc. This response is scored failure without further questioning.
Other subjects, mostly above the 14-year level, adhere to the answer "50 pounds," however strongly we urge the argument about the water holding up the fish. In response to our question, "_How can that be the case?_" it is sufficient if the subject replies that "The weight is there just the same; the scales have to hold up the bucket and the bucket has to hold up the water," or words to that effect. Only some such response as this is satisfactory. If the subject keeps changing his answer or says that he _thinks_ the weight would be 50 pounds, but is not certain, the score is failure.