LessWrong has been around for 10+ years, CFAR's been at work for around 6, and I think there have been at least a few other groups or individuals working on what I think of as the "Human Rationality Project."
I'm interested, especially from people who have invested significant time in attempting to push the rationality project forward, what they consider the major open questions facing the field. (More details in this comment)
"What is the Rationality Project?"
I'd prefer to leave "Rationality Project" somewhat vague, but I'd roughly summarize it as "the study of how to have optimal beliefs and make optimal decisions while running on human wetware."
If you have your own sense of what this means or should mean, feel free to use that in your answer. But some bits of context for a few possible avenues you could interpret this through:
Early LessWrong focused a lot of cognitive biases and how to account for them, as well as Bayesian epistemology.
CFAR (to my knowledge, roughly) started from a similar vantage point and eventually started moving in the direction of "how to do you figure out what you actually want and bring yourself into 'internal alignment' when you want multiple things, and/or different parts of you want different things and are working at cross purposes. It also looked a lot into Double Crux, as a tool to help people disagree more productively.
CFAR and Leverage both ended up exploring introspection as a tool.
Forecasting as a field has matured a bit. We have the Good Judgment project.
Behavioral Economics has begun to develop as a field.
I recently read "How to Measure Anything", and was somewhat struck at how it tackled prediction, calibration and determining key uncertainties in a fairly rigorous, professionalized fashion. I could imagine an alternate history of LessWrong that had emphasized this more strongly.
With this vague constellation of organizations and research areas, gesturing at an overall field...
...what are the big open questions the field of Human Rationality needs to answer, in order to help people have more accurate beliefs and/or make better decisions?