Ok. Interesting point, but did this group of Asians take English language courses at school? Do they have knowledge of American culture via entertainment channels? Perhaps the Africans who allegedly got low scores were people who grew up living in tribes in the wild, and only came into the city where they ended up getting tested recently. I met a person whose mother fell in love with an African tribesman and I read her memoir on the experience - it wasn't long ago that she met him, a decade or two maybe. There may be a large proportion of people in Africa who literally grew up in a jungle.

In addition to straight up single-culture cultural differences, there are also variations from one culture to the next between which foreign cultures they've been exposed to (if any) and enjoy. Some cultures seek to limit their exposure to the outside (North Korea) while in others, the ideal is to embrace them (USA). For instance, here, there are many fans of Asian culture - think anime, Japanese video games and lovers of Thai food. Do they have a multicultural atmosphere like that in Africa? Sure there are American missionaries around who probably bring teacups and the like, but there's a giant difference between occasionally seeing some white people with some cups they didn't tell you anything about because they were too busy feeding starving children versus being taught their language in a class and spending time absorbing culture from their entertainment products.

Not only that, but differences between one IQ test and another could be gigantic when it comes to how many culture-dependent questions are in them. If you haven't specifically controlled for that during test design, that would be completely random. Maybe the Asians just so happened to get the test that had fewer cultural questions on it, and the Africans got one that was thoroughly based on many obscure pieces of cultural knowledge.

What we really need to be asking here is this:

Has anyone done a culture fair test for multiple different countries, using the exact same test with each one, and controlled for factors like whether the people being tested were schooled as children, whether they ever experienced starvation (that can cause brain damage) and any other important things?

Only if all the factors are controlled for would we have relevant data.