.. My personal guess about Canon parsel-tongue is that it creates a mind in the snake you talk to based loosely on your own - Hence the python in the zoo just wanting to escape it's cramped living situation, and thus the Basilisk in hogwarts being all murdery - it's nothing more than a funhouse mirror of Voldemort.
This was never tested, because Canon Harry has brain damage from starvation and various other psychological trauma inhibiting his thinking, and never even tried asking the basilisk to back off.
The HPMOR basillisk cannot possibly bear any resemblance whatsoever to the canon one anyway, Because that thing couldn't teach anyone anything.
My personal guess about it is that it is that most people attribute to animals a lot more agency than they really have, and the story is written with an authorial worldview that assumes that most people's views on this matter are actually true. Given that worldview, no explanation is needed at all. Of course, that worldview is itself inconsistent, but the inconsistencies have relatively little relevance to talking to snakes.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 113.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
IMPORTANT -- From the end of chapter 113: