Overcomingbias and Lesswrong have seen considerable discussion of several key aspects of the world that do not directly bear on rationality (listed as question-headings, below). These discussions are interesting in two lights. First, they are interesting as data about important aspects of how our world works -- analysis you might want to know as you figure out how to acheive your goals. Second, they are interesting as case studies in how groups of aspiring rationalists can go about figuring things out, and whether careful thinkers do, in practice, end up agreeing [1] on a common set of probability estimates. We can examine these discussions to gather evidence about whether we can or can't think more productively than communities that don't spend time honing their "rationality".
Robin Hanson has argued strongly that it does not, and that a vast chunk of America's national economy is doing nobody any good. Many commenters have disagreed, agreed, or cited research in support of more nuanced positions. You can read the details in Robin Hanson's posts, and the ensuing comments threads:
Should you go to an elite college?
Both Eliezer Yudkowsky and Robin Hanson
What impacts
Are we living in a simulation, or are we otherwise basically confused about what the world is?