It seems obvious that Tunnel in the Sky is a direct response to William Golding's Lord of the Flies. Indeed, I imagine Heinlein putting down Golding's book and heading straight for the typewriter grinding his teeth and muttering "Revert to savagery my ass!"Heinlein and I would've agreed on a lot of basic issues just like this one. Granted, we wouldn't have agreed on everything, but nobody's perfect. Poor guy.