Some unrefined thoughts on why rationalists don't win + a good story.

Why don't rationalists win?

1) As far as being happy goes, the determinants of that are things like optimism, genetics, good relationships, sense of fulfillment etc. All things you could easily get without being rational, and that rationality doesn't seem too correlated with (there's probably even a weak-moderate negative correlation).

2) As far as being right goes (epistemic rationality), well people usually are wrong a lot. But people have an incredible ability to compartmentalize, and people often exhibit a surprising degree of rationality in their domain of expertise. And also, you could often do a solid job of being right without much rationality - heuristics go a long way.

Story:

• There's a pool of water around the base of my toilet, and I'm sitting there like an idiot trying to use the scientific method to deduce the cause.
• I figured out that it only shows up when I turn the shower on. Not when I flush the toilet, and not when it's idle.
• I closed my shower curtains as best I could, and didn't observe any water coming from the shower head and landing near the toilet. Additionally, the pool of water around the toilet was only around the toilet base. The area between the shower and the pool of water was dry. So it didn't seem that it was dripping down the bath tub and drifting to the shower base (especially because the floor is flat).
• So, I was pretty confident that there was some sort of damage to the pipes that caused water to come out from under the toilet when I turned the shower on.
• I called the repair guy. He did his thing, and concluded that the pipes were fine, and that the water must have been coming from the shower head. I told him my theories, and he smiled and didn't change his conclusion. It turns out he was right. There's this really thin stream of water that is coming out from the shower head, splashing, and causing the problem. I had previously considered this (briefly), but thought that my shower curtains were sealed enough to prevent this. But it turns out that there's this little crease that it's getting through.
• Final score: Repair Guy - 1. Rationalist - 0.

So then - why rationality?

• Simple: it drastically raises the ceiling of how much we could accomplish in each of these fields (instrumental and epistemic).
• Also, in theory, it shouldn't have any costs associated with it. You should still be able to benefit from the same heuristics and the same happiness indicators as an irrational person (actually, there's probably some that you have to sacrifice by being a rationalist).