It might be worth taking a look at Karen Horney's work. She was an early psychoanalyst who wrote that if a child is abused, neglected, or has normal developmental stages overly interfered with, they are at risk of concluding that just being a human being isn't good enough, and will invent inhuman standards for themselves.
I'm working on understanding the implications (how do you get living as a human being right? :-/ ), but I think she was on to something.
I wasn't abused or neglected. Did she check experimentally that abuse or neglect is more prevalent among rationalists than in the general population?
Of course that's not something a human would ordinarily do to check a plausible-sounding hypothesis, so I guess she probably didn't, unless something went horribly wrong in her childhood.
Here's the new thread for posting quotes, with the usual rules: