One of my favorite academic papers of all time is Nisbett & Wilson’s classic, “Telling More Than We Can Know: Verbal Reports on Mental Processes” (Psychological Review, vol. 84, pp. 231-259, 1977). As the title suggests, it is about our error-prone and incomplete recollection of mental processes. I cite this paper often when rolling my eyes at tech company surveys and focus groups, or any time people try to explain why they think what they think.
Anyway, here is an anecdote from the paper that I used in a recent talk:
In Maier’s (1931) classic experiment, two cords were hung from the ceiling of a laboratory strewn with many objects such as poles, ringstands, clamps, pliers, and extension cords. The subject was told that his task was to tie the two ends of the cords together. The problem in doing so was that the cords were placed far enough apart that the subejct could not, while holding onto one cord, reach the other. Three of the possible solutions, such as tying an extension cord to one of the ceiling cords, came easily to Maier’s subjects. After each solution, Maier told his subjects, “Now do it a different way.” One of the solutions was much more difficult than the others, and most subjects could not discover it on their own. After the subject had been stumped for several minutes, Maier, who had been wandering around the room, casually put one of the cords in motion. Then, typically within 45 seconds of this cue, the subject picked up a weight, tied it to the end of one of the cords, set it to swinging like a pendulum, ran to the other cord, grabbed it, and waited for the first cord to swing close enough that it could be seized. Immediately therafter, Maier asked the subjecct to tell about this experience of getting the idea of a pendulum. This question elicited such answers as “It just dawned on me.” “It was the only thing left.” “I just realized the cord would swing if I attached a weight to it.”
All of the subjects reported that the useless cue had been helpful, meanwhile denying that the crucial one cue had helped at all. Remarkable.