I guess that by not falling in line I just disproved the story.
Oh, another of the things I find questionable about the story is the notion that somehow the monkeys are stupid sheep for keeping each other from climbing the stairs. Hey, if I see someone walk into a room and get his head lopped off, I sure am going to avoid walking in the room myself - and keep my friends from going in there. That’s just called “learning”. If later, someone is observed going in the room and NOT getting their head lopped off, the same learning will lead to me considering that maybe the danger has passed.
About the only significant example I can think of people continuing some antiquated behavior ad-infinitum despite longterm and overwhelming evidence to the contrary, is religion. But that’s a debate for another day. 😃