* Once you know the mean IQ and standard deviation of a population and the # of members in each group, it’s a trivial mathematical exercise to determine the number that will exceed a certain threshold. If we call it say IQ145+ which is real genius territory, for an Ashkenazi Jewish population this is only maybe 2.x SDs out from the population mean so there is still a fair amount of daylight under the bell curve. Same for Asians except their 2.x is a little higher than the Jewish 2.x but there are a lot more of them. For a white population, it’s 3 SDs where the line is getting awfully close, but there are a whole lot of white people in the US in relation to the # of minorities (at least there used to be) so you still get a goodly amount of geniuses. For blacks, it’s 4 SDs where the line is fast approaching zero. The # of actual black geniuses that you see (very few) is neither more nor less than what the models would predict. If you drill down and look at the few blacks who score over 750 on the SAT (there are only a couple of hundred each year vs. tens of thousands of Asians) you’d find that they are mostly either African-Africans or half white or both (like Obama) and the number that are purebred American slave descendants like Moochelle is close to nil.
* If you want to know what cultures produce inventors, look at the ones that had high-craft cultures before the modern era. Japan was a high-craft culture. Europe was a collection of high-craft cultures.
You get a high-craft culture when you get X minimum percentage of its citizens who are usually gifted in visual-spacial and mechanical skills, and when that culture’s economy has progressed to the point where craftsmen are able to earn a good enough living that they can have more than 2 children per family, and thus begin to increase their descendants in a Malthusian manner. This increases the total amount of high-performing visual-spacial and mechanical genes in each generation, and therefore increases the potential numbers of craftsmen and inventors with every new generation. You can’t get a homegrown industrial revolution without this process happening. You won’t have enough talented people to create it otherwise.
Africa has never been a high craft culture, therefore it does not produce inventors. This is not a surprise.