This site often speaks of rationality and intelligence as though they were the same thing, and that someone, by becoming more rational, becomes more intelligent for practical purposes.
Certainly it seems to me that this must be to some extent the case, but what is the exchange rate? If a person has an IQ of 100, and then they spend a year on lesswrong, reading all the sequences and taking the advice to heart, training their skills and identifying their biases and all that, at the end of it, presumably their raw IQ score is still 100, but if we measure how they do on correlated indicators regarding their lifestyle or something, should we expect to see them, in some way, living the life of a smarter person? How much smarter?
How many points of IQ would you be willing to give up to retain what you have learned from this site?
Personally I would answer "less than one". It seems like it SHOULD be useful, but it doesn't really feel like it is.
Edit: This comment was written in response to why, if rationality is supposedly so helpful, it isn't commonplace by now.
A lot of the information that makes LW's brand of rationality more distinct (cognitive biases, various systematic bayesian statistical techniques, decision theory stuff, etc.) is really new.
Like, Heuristics and Biases came out in 1982 (though they did the research a decade or so before hand), Jaynes didn't describe/justify the maximum entropy distribution until 1957, the Solomonoff prior wasn't until 1960, and the AI research that gave people a concrete way to think about thinking didn't really start until the 1950s. Causality was published in 2000.
So it hasn't really had the time to become widely adopted, or fleshed out yet.
Before then though, less strict rationality has actually helped a lot of people. Europe took over the world because of the Renaissance, for instance. The Romans took over because of superior military organization (a particularly brutal form of instrumental rationality).
The Persians built and maintained (for a while, anyway) the Achaemenid Empire largely because of their superior logistical and diplomatic skill, backed up by the army that they built.
The Byzantines maintained the remnants of the Roman Empire for a few hundred years based mostly on their diplomacy.
Oops, edits crossed in midstream. This reply made a lot more sense in conjunction with the original post as it was originally written.
Edit: Haha, yes.