Ok, I have to weigh in here. First, I am a white South African. I lived there for 25 years and the last 18 lived in Germany, in a mid-sized university town.
My mother-in-law here lives in (and the wife grew up in) a small rural little town and I lived there for about 3 years too, because a) I got the house for free and b) I was stupid.
I can ensure you, the educational level of Germans who grew up in a small agricultural town after WW2 is astoundingly, ridiculously low. It is very frustrating what a total, utter, complete lack of intelligence you get when grandma has her birthday and her old friends (who are now in the 60s) sit around the table and talk. I always tell my wife that dropping a thermonuclear warhead on her hometown would raise Germany's average IQ by 2 points. They are simple not capable of having ANY form of intelligent conversation whatsoever.
To give an example, Germany has the best passenger train system in the world (with the possible exception of Switzerland). My mother-in-law has a small train line running RIGHT IN FRONT OF THE HOUSE. Until she was 60 years old she was simply not capable of riding the thing because she was too primitive/stupid/illiterate to figure out the time tables (you actually have to change trains once to get into the city, which is a 22 minute trip). This was in the year 2005 AD. The 21st century. And she is by no means an exception, she had some friends with her on her first trip and they could not quite figure out how to get home with the train.
The problem goes further with her children. She never stimulated them. There were no books in the house, no encyclopedia, no anything. My wife did get out, she has advanced medical degree and but she has little knowledge of the world and not much common sense at times. Got it from mom, who got it from her mom, who got it from hers. SImply no interest in the outside world because it was never an issue at home.
The comparison to my house (in South Africa) where my father had a degree, owned a business, did a lot of electronics at home (I first played with computers at 8 in 1978) and my mother had a high-school diploma and training as a bookkeeper is like the difference between night and day. I can actually have an intelligent conversation with my parents.
I know quite a few blacks in SA who can outthink, out-talk and outgun anyone in the rural classes of one of the world's most advanced industrial states.
The problem is not race. Blacks in SA and peasants in Germany (who live 15 km from a thriving city with an old university!) have the same problem. Complete lack of stimulation during childhood and no interest in education because it simply was not something that came to mind. Remember, in Germany free education to tertiary level was available many years ago, so it was not really for a lack of opportunity. The people simply are not educated enough, and do not get enough stimulation from their parents, to even think about the idea that an education is something worth having. It is like some kind of inter-generational momentum. Children often do what their parents do and what their parents did and a few top-achievers escape the place but living in a rural place, sweet and romantic as it may be, simply dooms you to semi-illiteracy.
And there lies the rub with Africa. Most of the people have never lived in a modern culture and it will take years and years for this to percolate through the system. Apartheid was a bunch of people who were educated who were transplanted and realized that is will take a long time to spread basic education, and simply did not have the resources to realistically do so.
I would like to add that the people from the old white industrial class in South Africa were not much better either, high-school or not.
This has little to do with race, and all to do with culture, which in turns is very much influenced by the environment in which the people of that culture lives.