Perry is trying to solve the following riddle: "What creature walks first on four legs, then two, then three?" He repeatedly tries to think of an animal that might walk on three legs, but he can only think of animals that walk on either two or four legs. Finally, he is told the correct answer: a human being, who crawls, then walks, then walks with a cane. Which one of the following is the most likely explanation of Perry's difficulty?
A) He has encoded the problem with too narrow a definition of "legs."
B) He doesn't have enough working memory capacity.
C) He doesn't have a sufficient knowledge base.
D) He is suffering from functional fixedness.

Question

Quizplus · Accepted Answer

Perry's difficulty is that he has encoded the problem with too narrow a definition of "legs," limiting himself to animals that walk only on two or four of them. He does not consider the fact that a person who requires a cane to walk may be considered to be walking on three "legs."

Perry Is Trying to Solve the Following Riddle: "What Creature