Procedure and Scoring, the same as in previous tests of this kind. The series are: 4–1–6–2–5–9–3; 3–8–2–6–4–7–5; and 9–4–5–2–8–3–7.
We have collected fewer data on this test than on any of the others, as it was added later to the test series. As far as we have used it we have found few “average adults” who pass, while about half the “superior adults” do so.
Superior adult, 6: ingenuity test
Procedure. Problem a is stated as follows:—
A mother sent her boy to the river and told him to bring back exactly 7 pints of water. She gave him a 3-pint vessel and a 5-pint vessel. Show me how the boy can measure out exactly 7 pints of water, using nothing but these two vessels and not guessing at the amount. You should begin by filling the 5-pint vessel first. Remember, you have a 3-pint vessel and a 5-pint vessel and you must bring back exactly 7 pints.
The problem is given orally, but may be repeated if necessary.
The subject is not allowed pencil or paper and is requested to give his solution orally as he works it out. It is then possible to make a complete record of the method employed.
The subject is likely to resort to some such method as to “fill the 3-pint vessel two thirds full,” or, “I would mark the inside of the 5-pint vessel so as to show where 4 pints come to,” etc. We inform the subject that such a method is not allowable; that this would be guessing, since he could not be sure when the 3-pint vessel was two thirds full (or whether he had marked off his 5-pint vessel accurately). Tell him he must measure out the water without any guesswork. Explain also, that it is a fair problem, not a “catch.”
Say nothing about pouring from one vessel to another, but if the subject asks whether this is permissible the answer is “yes.”
The time limit for each problem is 5 minutes. If the subject fails on the first problem, we explain the solution in full and then proceed to the next.