I've become good at resolving fights in my family - people don't understand why the other person's angry, and I can explain the mistakes they're making in terms of probability, or in biases, cognitive science or often status-seeking behaviour, and they understand.
Also, I've become a lot better at managing my life romantically. I kept changing my mind about whether someone had feelings for me - she did, she didn't, she did, she didn't - and I could never be sure if I was re-interpreting evidence to suit my preferred hypothesis. So I decided upon a test, decided ahead of time how I should update my beliefs based on how she'd react, and did it. Saved myself a lot of heartache.
Learning about priming, consistency effects and cached thoughts has also helped me steer my future self towards what I'd like to be.
So I decided upon a test, decided ahead of time how I should update my beliefs based on how she'd react, and did it.
This sounds virtuous in terms of empiricism, but testing someone to see if she has feelings for you is kind of a nasty thing to do in general... what was your test?
Related to: Tsuyoku Naritai! (I Want To Become Stronger), Test Your Rationality, 3 Levels of Rationality Verification.
Robin and Eliezer ask about the ways to test rationality skills, for each of the many important purposes such testing might have. Depending on what's possible, you may want to test yourself to learn how well you are doing at your studies, at least to some extent check the sanity of the teaching that you follow, estimate the effectiveness of specific techniques, or even force a rationality test on a person whose position depends on the outcome.
Verification procedures have various weaknesses, making them admissible for one purpose and not for another. But however rigorous the verification methods are, one must first find the specific properties to test for. These properties or skills may come naturally with the art, or they may be cultivated specifically for the testing, in which case they need to be good signals, hard to demonstrate without also becoming more rational.
So, my question is this - what have you become reliably stronger at, after you walked the path of an aspiring rationalist for considerable time? Maybe you have noticeably improved at something, or maybe you haven't learned a certain skill yet, but you are reasonably sure that because of your study of rationality you'll be able to do that considerably better than other people.
This is a significantly different question from the ones Eliezer and Robin ask. Some of the skills you obtained may be virtually unverifiable, some of them may be easy to fake, some of them may be easy to learn without becoming sufficiently rational, and some of them may be standard in other disciplines. But I think it's useful to step back, and write a list of skills before selecting ones more suitable for the testing.