This. The following question is likely to fool a lot of people, too. "I have a rooster named Pat. (Lots of other details so you're likely to forget Pat is a rooster, not a hen). Pat flies to the top of the roof and lays an egg right on the ridge of the roof. Which way will the egg roll?"
But if you omit the details designed to confuse people, they're far less likely to get it wrong: "I have a rooster named Pat. Pat flies to the top of the roof and lays an egg right on the ridge of the roof. Which way will the egg roll?"
It's not about reasoning ability, it's about whether they were paying close attention to your question, or whether their minds were occupied by other concerns and didn't pay attention.
But if you omit the details designed to confuse people, they're far less likely to get it wrong: "I have a rooster named Pat. Pat flies to the top of the roof and lays an egg right on the ridge of the roof. Which way will the egg roll?"
It's not about reasoning ability, it's about whether they were paying close attention to your question, or whether their minds were occupied by other concerns and didn't pay attention.