We think that we know a little bit about how to raise intelligence. Just turn down the suppression of early CNS growth. If you do that in one way the eyeball grows too big and you are nearsighted, which is highly correlated with intelligence.
There is now substantial evidence that there is a causal link between prolonged focusing on close objects—of which probably the most common case is reading books (it appears that monitors are not close enough to have a substantial effect) - and nearsightedness/myopia, though this is still somewhat controversial. This is the typical explanation for the correlation between myopia and IQ and academic achievement.
A genetic explanation is possible, and would be fascinating, but I wouldn’t want to accept that without further evidence. If the genetic explanation is true and environment makes no contribution, then I think one should find that IQ is more highly correlated with myopia than academic achievement—I don’t know if this has been found or not.
Why is LessWrong not an Amazon affiliate? I recall buying at least one book due to it being mentioned on LessWrong, and I haven’t been around here long. I can’t find any reliable data on the number of active LessWrong users, but I’d guess it would number in the 1000s. Even if only 500 are active, and assuming only 1⁄4 buy at least one book mentioned on LessWrong, assuming a mean purchase value of $20 (books mentioned on LessWrong probably tend towards the academic, expensive side), that would work out at $375/year.
IIRC, it only took me a few minutes to sign up as an Amazon affiliate. They (stupidly) require a different account for each Amazon website, so 5*4 minutes (.com, .co.uk, .de, .fr), +20 for GeoIP database, +3-90 (wide range since coding often takes far longer than anticipated) to set up URL rewriting (and I’d be happy to code this) would give a ‘worst case’ scenario of $173 annualized returns per hour of work.
Now, the math is somewhat questionable, but the idea seems like a low-risk, low-investment and potentially high-return one, and I note that Metafilter and StackOverflow do this, though sadly I could not find any information on the returns they see from this. So, is there any reason why nobody has done this, or did nobody just think of it/get around to it?