Why was Africa so underdeveloped before colonization?

Jun 2013
This is a very interesting thread. I think, and this is my opinion, the answers to the OP could be found in the following posts:
#8 - @Tuthmosis III
#37 - @KurwaGoy
#38 - @JeanDukeofAlecon

IMO these are the best "general" answers to such a "general" OP.

Generally it's the diffusion of technology, agriculture, culture, innovation, etc. due to the geographic orientation of Europe - Asia - North Africa. Notice it's East-West within a few latitudes. This E-W axis shared similar day lengths, seasons, climates, rainfalls or lack of and biomes. As drastic as they might be they didn't compare to the North-South longitudenal axis.

Plants/animals in the E-W axis became domesticated. More food led to more people - running into each other - no isolation.

The E-W axis is a landmass from China to Gibralter. Peoples were migrating east to Asia; west to Europe in waves. With larger populations comes immunity to diseases, more need for communication, innovation speads rapidly.

The size of the population determines the complexity. The complexity produces the culture. This culture - like a petrie dish - morphs and grows things like governments, religions and constant wars that lead to unending co-operation or conquest.