Necessary to include "in Africa" in that sentence? Isn't it true of humans in general?

A lot of education isn't a very strong signal in places where education is trivial to access.

This is actually a very good point. I'm from Africa and currently living in North America. It is interesting to compare and contrast my views about the value / benefit of education vs my parent's. In a lot of countries in Africa, education is a privilege (I was VERY lucky). Few can access it so it is a rather strong signal.

I do agree with the spirit of the parent comment however, in that there are a lot of false and unconscious assumptions about "Africa" held by NAers that need to be rooted out and extinguished.

Not just education but also quality education is a priviledge.

People who don't manage to get a lot of education also turn out to be pretty smart at the same rate.