For example, if you look at a 30 year period in the second half of the 20th century, the standard primary and high school math programs probably didn't change dramatically during this time, and they certainly didn't become much harder.
I'm not so sure. Here's a 2005 paper ('Rising mean IQ: Cognitive demand of mathematics education for young children, population exposure to formal schooling, and the neurobiology of the prefrontal cortex') suggesting that 'cognitive demands of mathematical curricula' in the US increased from about 1950.
Anecdotally, I remember occasionally surprising my parents by telling them about what I was learning in math - my schools' math syllabuses apparently went faster than my parents'.
The question is if this effect (and/or effects like it in other school subjects) would be enough to mask the Flynn effect at younger ages; I guess it could be enough to partly mask it but not wholly mask it, in which case there are other explanations at work too. Maybe the Flynn effect is less in children than adults as well.
Unfortunately, I think we'll have to wait for further major advances in brain science to make any conclusions beyond speculation there. Psychometrics suffers from too many complications to be of much further use in answering such questions (and the politicization of the field doesn't help much either, of course).
Neuroscience could certainly help, but I would think one could make a good start just by repeatedly IQ-testing a huge number of kids through childhood, tracking them into middle age, plotting child IQ against adult achievement, and drawing a lowess regression line through it. If the line starts out relatively steep but flattens out with increasing IQ, you and me are right: IQ isn't that informative about high flyers. I wouldn't be that surprised if someone hadn't already done something like this with the Project Talent data or some other big database.
Sputnik was a huge shock to the U.S., causing fear that the Soviet Union would eventually overwhelm or eclipse the U.S. One of the results of that fear was the enrollment of math professors in the design of a new model math curriculum called the New Math, which was widely deployed and in most places where it was deployed represented a sharp break with past math curricula. Elementary-school children were taught things like how to do addition in bases other than ten. The "laws of algebra" (e.g., the commutativity property) were introduced much ...
Edit: Q&A is now closed. Thanks to everyone for participating, and thanks very much to Harpending and Cochran for their responses.
In response to Kaj's review, Henry Harpending and Gregory Cochran, the authors of the The 10,000 Year Explosion, have agreed to a Q&A session with the Less Wrong community.
If you have any questions for either Harpending or Cochran, please reply to this post with a question addressed to one or both of them. Material for questions might be derived from their blog for the book which includes stories about hunting animals in Africa with an eye towards evolutionary implications (which rose to Jennifer's attention based on Steve Sailer's prior attention).
Please do not kibitz in this Q&A... instead go to the kibitzing area to talk about the Q&A session itself. Eventually, this post will be edited to note that the process has been closed, at which time there should be no new questions.