Strong extended kinship ties are associated with less economic prosperity all over the world, it just in Africa but Pakistan, the Middle East, etc.
There is a plausible argument that it’s causal. Europe had weaker kinship ties—for various reasons, including the Catholic church’s ban on cousin marriage—back in the middle ages, before Europe began pulling away from the rest of the world in terms of GDP per capita. Even within the U.S., communities with weak kinship ties (e.g. Northeastern Anglo-Protestants) are more economically successful than communities with stronger kinship ties and clan structures (e.g. Appalachians).
Arguably, more atomized societies with weak kinship ties foster the development of civil institutions and governments to compensate for the social structural functions that would otherwise be performed by kinship networks.
> There is a plausible argument that it’s causal. Europe had weaker kinship ties—for various reason
Explain China[1] and its steep ascent, blowing past all European countries, and soon - the USA.
1. Or India, to a lesser extent. There's a lot of recency bias when it comes to economic outcomes, as if we're at the end of history. I'm guessing at least one 19th century British industrialist/gentleman probably praised their Anglo-Saxon heritage and the Protestant (Anglican) faith as necessary ingredients to national wealth, as opposed to the fallen Catholic empires of Spain and Portugal, or the heathens in Africa, the Indo-Pacific, the Middle and far East.