The Rats That Could Hear the Floor
Richard Feynman's 1974 Caltech story about maze rats and a noisy floor, and what it says about trusting your own account of your mornings.
In his 1974 Caltech commencement address, Richard Feynman described an experimenter named Young, working in 1937, who wanted to know whether rats could learn to run to the third door down a corridor instead of the door where food had appeared before. The rats kept going to the food door. Young painted the doors identically, changed the food’s smell between runs, and covered the corridor to hide the lab’s layout. The rats still found it. Finally he discovered they could tell “by the way the floor sounded when they ran over it.” Only a corridor built on sand ended the shortcut.
The rats were not clever about doors. They used the cheapest cue available, and it had nothing to do with the question being asked.
Self-reports have a floor sound. Ask yourself whether you got up on time this week and you answer from whatever is easiest to recall: the intention, the one good Wednesday, the general feel of the week. None of that is what time your feet hit the floor on each of seven days.
Feynman’s line from the same talk: “The first principle is that you must not fool yourself — and you are the easiest person to fool.” Young’s rats show how little effort that takes. Nobody has to want to be fooled; a subject will find the shortcut unaided.
The remedy came from Young: sand. Remove the cue the subject would have leaned on, and keep a record made at the moment by something other than memory. Video proof beats self-report for the same reason, and the same quotation anchors a piece on why excuses are data.
The floor never lied about being a floor. It just answered a different question than the one the experiment was asking.