How can one measure this? My main impression from ES Yudkowsky and his compatriots are they are overly insular and suffer tremendously from the DKE. I've already been banned on Lesswrong for some reason, they are over controlling and neurotic. How can one possibly "measure" "rationality"? How right you are? How accurate your beliefs are? How do we even know any of our beliefs are accurate if no one has solved epistemology?
With your aggressive tone, it's perhaps understandable why you've run into mod trouble on LessWrong. But as a simple existence proof, the forecasting techniques and training materials described by Phillip Tetlock in books like "Superforcasting" have been repeatedly shown to somewhat improve people's skill at making all kinds of predictions across varied subject areas. Forecasting isn't the same thing as LessWrong-style "rationality", but it's close -- both are general reasoning skills that focus on avoiding bias and understanding probability, rather than domain-specific expertise.