I'm positive I have heard the story in the first completion before, just phrased differently. GPT-3 is perhaps not plagiarizing the exact phrasings here, but it is regurgitating someone else's explanation for how religion and society evolved.

"They also decided that this god must be interested in them, since they were the only beings in the world that they knew about. They decided that this god must have given them instructions on how to live their lives, since they didn't know any better."

I can't put my finger on it, but these sentences feel very familiar. They must come from somewhere.