For anosognosia to be a common failure mode, and for the split brain patient's peculiar left side's behaviour, the rationalization got to be a common mode of thought. Perhaps there's a module in the brain that prepares speech but has very little impact on the beliefs and decisions; I ask you why your hand is not scratching your back, and it says, because my back is not itching, and that happens to be correct, but it would say same if the arm was paralysed and back was itching and it wasn't 'told' (by the part doing actual thinking) that arm was paralysed.
When you say you aren't rationalizing, perhaps that module still works by rationalization, it just happens to be quite plausible. Maybe that's how construction of sentences works in the first place when talking about nearly anything.
Upvoted for mentioning split brain patients. It made me think of a test of the question "does everyone rationalize"? See whether split brain patients (e.g., ask someone who ask worked with them, or read their writings) vary greatly in the confidence that they assign to their rationalizations of their behavior. All I remember reading of is patients who assign very high confidence to these rationalizations, but that could just be publication bias. If there is large variance and especially if some patients don't do it much at all (i.e., when their n...
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.