In response to the folk suggesting that our questions were just unclear, etc.:

I notice rationalization all the time too (in myself and in others); but there totally seem to be people who don't ever notice it in themselves. Lots of them. Including both folks who seem never to have trained in rationality-type-stuff at all, and folks who have. I ignored my first counter-example, and my second, but not my third and forth; especially after the fourth counter-example kindly allowed us to cross-examine them for some hours, to go try accosting strangers with weird questions and see if they noticed themself rationalizing while approaching said strangers, etc.

Mercurial, and Eliezer, both suggested an analogy to the "thinking in words" vs "thinking in images" thing; some do one and others do another, and many tend to assume that everyone must experience life that way. We all updated toward thinking that there is some actual thing going on here -- something we were initially not modeling.

But, I'm still confused about:

1. Whether we're just still missing something obvious anyhow. Maybe our fourth counter-example, who consented to answering gobs of questions and trying experiments for us, was a fluke? (Try asking people yourself, please; don't just say that it must be experimental error because you don't work that way)
2. Whether they don't rationalize, or just don't notice themselves rationalizing. (Fourth datapoint seemed to maybe actually never make up reasons for choices; don't have data on the others really).
3. What exactly the boundaries are on "rationalizing" -- what exactly it is, that a sizable portion of the folks we've talked to never notices themselves doing.