If you below 80 IQ I would say it's impossible to make it in IM field on your own. For instance people below 70 IQ piss in their own water supply, they can't understand simple cause of a problem.
I would also suggest to look at WORLD MAP by IQ interesting stuff.
Crystallized IQ is obviously always going to be worse in a place like Africa based on the quality of education there, but fluid IQ should technically be roughly the same globally if IQ has nothing to do with either a) biology or b) culture. (Which in fact are the two things it mainly depends on obviously)
A lot of people think that IQ is something solely based on what you're born with. It plays a huge part, but culture plays a bigger role.
ie. the tests for fluid intelligence are things like how fast you can identify geometric shapes and the way they would look if they were rotated 90 degrees and shit like that (amongst a lot of other things)... but if your culture doesn't even have books, then your ability to visualise geometric shapes at all will be slower than someone that has spent their whole life seeing those geometric shapes on TV, at school, everywhere really.
Your mind gets passive practice all the time and is much more familiar with the kinds of concepts in the test if you're from a country like South Korea or Germany than Nambia or DRC for example. So I think biology would play a big role (both cross-ethnically and inter-ethnically), but I think that culture plays the biggest role.
Proof of this is seeing people from traditionally "low IQ" places on that map go to do university in Europe or the US and then become engineers etc while others stay in their origin country and would get a result of 75 on an IQ test.
Also, a lot of people don't realise that IQ tests are about the speed of your thought processing. You don't get unlimited time to complete the test, and actually unless you were a bonafide genius there's no way to complete the whole test anyway. So if you're from NYC and your pace of life is super fast all the time, your mind will automatically perform better than someone who's used to an incredibly slow pace of life with no access to the internet even.
Hence there's an obvious correlation between IQ in that map and the level of development of each country. If it was a pure test of "biological intelligence" instead of IQ, the level of development shouldn't be a factor at all, but blatantly it is.
People from developed and less-developed places' brain wiring is going to be completely different after years of one person thinking rapidly constantly, rushing to work etc, and the other person not having anywhere near the same cognitive pressure every day. The test is as accurate as it can be, but the results don't tell you as much as they should and there's nothing really beneficial that comes out of it other than confirming that the resources and experiences you have throughout your early years (and beyond) play a huge role in your cognitive development.
Basically we all have our own individual limits on how "smart" we could each become, but smartness is way more about your surroundings (particularly during childhood) than your biology.