The way I test the rationality of the people around me is by lying to them, generally about irrelevant things, and seeing if they can unravel the lies.

In virtually all cases, what happens is that they simply learn not to believe anything I say, at which point I start telling the truth in a way that makes it seem like a lie. People dial their credulity up and down, and eventually just give up.

From the general attitude of the people here, I doubt most of them have gotten beyond the "calibration" mindset either, thinking of rationality like tuning a TV, just trying to correct for the biases. It isn't that simple.

If you want to test your rationality, you have to try and determine the truth about something difficult, and you have to be able to verify the results. This can be done by:

1. having someone around who knows the answer to begin with, and is putting the problem to you as a test

2. working on a problem where the correct answer can be verified because it allows you to make predictions of some kind

3. working on a problem so tricky that even coming up with an answer which is internally consistent is very difficult, i.e. the miracle of the sun