Tolman's rats wandered a maze for ten days with no food at the end and showed no improvement. On day eleven food appeared, and their error rate dropped almost immediately to the level of rats rewarded from the start. Why was this a problem for a strictly behaviourist account?

A. Because the learning had happened but had nowhere to show itself.

The speed of the change is what does the damage: gradual improvement would mean learning began on day eleven, and dropping straight to the rewarded group's level means the layout was already known. Reinforcement gave them a reason to use knowledge they already had, and a theory built entirely on consequences has no account of what was accumulating meanwhile.