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 nonverbal hemisphere is cued to do something, their verbal hemisphere says, I don't really know why I did that action), then that is a sign that some people really don't rationalize much.
Could be, but they have a lot of time for the other hemisphere to give up explaining, and they have a whole hemisphere there, some of which may not be rationalizing and may prod the rationalizing module with a clue that right side is now independent.
What I'm thinking of, is the possibility that speech works by rationalization-style process. If you consider speech from decision theory perspective - speech is just another instance of making moves that affect the future - in principle it is about as relevant to internal decision making as your spinal cord's c...
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.