The one I have in mind is this. This post and its comment thread, combined with the final net results of voting, in my opinion decisively refute the idea of any universally applicable "sanity waterline" that is supposedly higher on LW than elsewhere. I don't think it's an exaggeration to say that the collective failure of rational thinking demonstrated there was so severe that it might as well have been a happy and approving discussion of horoscopes, healing crystals, or the Mayan 2012 doomsday.
It is the prospect of such things starting to re-emerge on a regular and frequent basis that has motivated my reactions in this thread.
Is the group reading and responding to these relationship posts representative of Less Wrong? I just skip over them.
.