This formula has been constructed after many years of experience. The words are chosen and partially arranged in such a manner as to strike easily almost all complexes which occur in practice. As shown above, there is a regulated mixing of the grammatical qualities of the words. For this there are definite reasons.^[1]

Before the experiment begins the test person receives the following instruction: “Answer as quickly as possible with the first word that occurs to your mind.” This instruction is so simple that it can easily be followed. The work itself, moreover, appears extremely easy, so that it might be expected any one could accomplish it with the greatest facility and promptitude. But, contrary to expectation, the behaviour is quite otherwise.