[exDemMom]

I think that civilization had to evolve in Northern and Western Europe because of scarcity. Due to scarcity brought by winter, Europeans had to plan to store food. That led to civilization advancing in Europe while in Africa, tribes were content to eat banana from the tree and hunt wildebeest for dinner.

That probably has something to do with it, but is not a complete explanation. For example, the early Native Americans in what is now Mexico and Central America built advanced civilizations in very lush jungles, where it is difficult to imagine that scarcity was an issue.

Another factor is that Africa seems to be a hotbed for various infectious diseases. When a child becomes deathly ill, the energy his or her body was using for growth (including brain development) is diverted towards trying to stay alive. Even if the kid survives, his brain development might be permanently impaired. Also, malnutrition has an adverse effect on brain development. Without addressing the issues of infectious disease and malnutrition, African children will always be less intelligent, less able to progress towards a more advanced civilization.

[Homer1]

Hence the need for progressives to ban ddt...

[palmer]

Another factor is that Africa seems to be a hotbed for various infectious diseases.

That's mostly an effect, not a cause. Unlike here, there is a primate reservoir for some of those diseases there. But the main cause of infectious disease is poverty and corrupt government.