I'd say it has more to do with the way the human brain processes skin color than poverty (blacks account for most of the prison population even accounting for socioeconomic status) or "race" (there really isn't such a thing--more genetic diversity in the human population of Africa than the rest of the world combined). Dark skinned (not just black Africans) people as a whole will, over the long term, always wind up making up the bulk of the population of the lowest tier of society, no matter which society they are in. Studies on young children show that the brain associates darker skin with masculinity, aggressiveness, and misbehavior, while white skin is associated with good behavior, trustworthiness, and femininity.
Following this line of thought leads to a societal setup that, when compared to history, has created the only successful black societies--segregation. Places like Harlem and Greentown were successful prior to integration (or their total destruction in the face of the prospect of integration), as were civilizations like Nubia, Mali, and Great Zimbabwe, which successfully traded with civilizations populated by lighter skinned peoples.
Many of the problems associated with dark skinned people around the world can thus likely be attributed to societal feedback loops (self-fulfilling prophesies) and brain drain, where the best and brightest "get out of the ghetto" rather than taking charge of the ghetto and making it a better place. Of course, many black societies also have their own cultural problems (corruption in Africa, anti-intellectualism in America, for example), but those don't explain the more widespread effect, and the fact that SKIN COLOR in and of itself is the most powerful predictor of IQ, no matter whether you are looking at America, India, Africa, Australia, or anywhere else.
If you think this post is racist, then you think reality is racist and there is nothing I can do for you.