As I noted in the previous thread, I can tell (sometimes) that I'm rationalising, even if my conclusion does turn out to be correct - it's a matter of arriving at a belief by a bad process. (In my case I get my polemicist on even though there's a little voice in my head noticing that my epistemology isn't quite justified. This is harder to notice because my output looks much the same those times I consider that I really do have my epistemological ducks in a row - I have to notice it while I'm doing it.)
Anna Salamon and I are confused. Both of us notice ourselves rationalizing on pretty much a daily basis and have to apply techniques like the Litany of Tarski pretty regularly. But in several of our test sessions for teaching rationality, a handful of people report never rationalizing and seem to have little clue what Tarski is for. They don't relate to any examples we give, whether fictitious or actual personal examples from our lives. Some of these people show signs of being rather high-level rationalists overall, although some don't.