I dont think if the low IQ level that black Africans have is the reason. The economy of Africa consists of the trade, industry, and resources of the peoples of Africa. Increased corruption and despotism are the main reasons for Africa's poor economy. Some people add the transition from colonialism has been shaky and uncertain, and the Cold War, but I dont buy the last to items.
Corruption: All forms of government are susceptible to political corruption. Forms of corruption vary, but include bribery, extortion, cronyism, nepotism, patronage, graft, and embezzlement. While corruption may facilitate criminal enterprise such as drug trafficking, money laundering, and trafficking, it is not restricted to these organized crime activities. In some nations corruption is so common that it is expected when ordinary businesses or citizens interact with government officials. The end-point of political corruption is a kleptocracy, literally "rule by thieves". CCM is a classic example.
The effects are on politics, administration, institutions and economic, but we are interested in economic effects. Corruption undermines economic development by generating considerable distortions and inefficiency. In the private sector, corruption increases the cost of business through the price of illicit payments themselves, the management cost of negotiating with officials, and the risk of breached agreements or detection. Mikataba ya Madini ni mfano mmoja wapo.
Despotism: a system of government in which the ruler has unlimited power, Tanzania and Uganda, for example. These rulers are not genius, Kikwete and Lowassa are good examples, but they want to have control over everything.
These are the two main reasons why we are all messed up.