I don't know that this is a particularly surprising outcome. Cognitive ability does require some contextual knowledge of the questions asked still. Also, in addition to motivation score can change based on the individual's condition (rest/sickness/medical conditions). No tool is perfect, but this one still has pretty good predictive value.
Should it? Broadly speaking, are countries with lower average IQ doing better or worse than countries with higher average IQs?
We know correlation doesn't meant causality. We also know that even in terms of IQ tests, you have at least some contextual knowledge requirement...without which your reasoning is impaired relative to competition. You can safely predict a low score implies at least in the short term that a person will struggle. Knowing scores can be improved (to a degree), this directly implies so can people to an extent, including reasoning around contextual knowledge that is learned later and improved health/conditions.
First of all, hi! I remember some of your Civ IV AAR's and they were awesome! I have no idea if you still play at all. I never got into Civ V or Civ VI and I'm finding it harder to play later in life.
Starting with your question about countries with lower than average IQ, the best explanation I can think of in Civ IV terms, is they are behind in tech and their cities need more Libraries, Universities, and Research Labs. The surround land needs some work, too. Then the research rate will increase, along with the average IQ.
It is noted that you used "contextual knowledge" three times.
Just in case you never read anything on the Flynn Effect, here is the Wikipedia article.
https://en.wikipedia.org/wiki/Flynn_effect
Here is a world map of estimated IQ by country, but I know little of the source. At least the source says to interpret the results with extreme caution.
https://iq-research.info/en/average-iq-by-country
Being perfectly honest, I'm still trying to put the pieces together. The factors I see in play are widespread education, many more people with high school diplomas and university degrees. We are also further removed from the farms, handling less equipment and more smart phones. Also, board games have become much more sophisticated! I saw a video where Flynn explains his theory, saying that today's people are much more open to the hypothetical than people from 100 years ago, and therefore perform better on IQ tests.
Regarding your comment that it is safe to predict that a low score implies that a person will struggle, JP is more blunt about it. He was listing common occupations by IQ range. When he got to less than 85, he said the problem is there is not much we can do with them, as far as finding an occupation goes. I just question if an average person from a country with an average IQ less than 85 will have the same kind of struggle upon moving to the USA. I have the same kind of question if you grab a normal kid from 1932, where the average IQ is 80 based on the 1997 scale. I wonder if IQ scales should be relative to country and time period.
Meanwhile, the Wikipedia article says the gains seem to be slowing down and most of the gains were in the lower end - and that would suggest improvements in basic needs and education and infrastructure.
Thanks for the response!