Carl Gustav Jung, Collected Papers on Analytical Psychology… (1916)
“ It often happens that the test-person actually does not know what to answer to the stimulus word. He waives any reaction, and for the moment he totally fails to obey the original instructions, and shows himself incapable of adapting himself to the experimenter. If this phenomenon occurs frequently in an experiment, it signifies a high degree of disturbance in adjustment. I would call attention to the fact that it is quite indifferent what reason the test-person gives for the refusal. Some find that too many ideas suddenly occur to them; others, that they suffer from a deficiency of ideas. ”
