These predominantly black cities in the US are actually quite fascinating. They show us what happens when a population is forced to live in a society and civilisation far beyond its evolutionary capacity and treated as equals. These cities are a kind of mid-way point between civilisation and what we see in much of Africa. Once segregation was done away with it was only a matter of time before blacks descended bit by bit into the state they're in now.

That's despite the fact that American blacks have a notable percentage of white blood in them helping prop them up a bit. An enterprising WN type with money and an education behind them could actually go to one of these cities for a year and write a book from an evolutionary/sociobiological perspective about this. Interviewing teachers, police etc.