But obviously today first and second generation Africans as a group are not only more successful than black Americans as a group, they’re more successful than many white ethnicities.
My understanding is that First generation Africans have IQ’s of 108, the highest or one of the highest of any ethnic group in the US. Given that Africa’s IQ in Africa is much lower, possibly ~70 IQ, it makes no sense that Africans would have a 70 IQ in Africa and their IQ would automagically jump to 108 in the US. IQ doesn’t work that way. It doesn’t skyrocket in one lifetime like that. In other words, obviously African immigrants are being highly selected for intelligence otherwise that 108 IQ would not even exist; instead they might have a 76 IQ.
Furthermore, the children of African immigrants are indeed crashing back down towards the mean African IQ, but they are not crashing all the way because the group is so high IQ to start with (108 IQ). So they are crashing from 108 down to 89 IQ. The children of African immigrants are ~20 IQ points less intelligent than their parents. However, an 89 IQ mean is very good for Blacks anywhere, so if US Africans maintain that 89 IQ, they will become one the most intelligent group of Blacks on Earth. Presently ,the smartest Blacks are Bahamains at ~93 IQ (although that figure is controversial) and 100 IQ for mulattos in Bermuda.
I do not think that their IQ’s will keep crashing down to 70 though, because regression to the mean doesn’t work that way. My mother told me that IQ’s tend to regress towards the mean, but they do not necessarily go all the way to the mean. In other words, if the White IQ is 100, parents with IQ’s of 140 may have kids with IQ’s of ~120, not 100. It won’t crash all the way down since it was so high to start with.
IQ’s cannot keep crashing down to the mean forever otherwise no group in the history of mankind would have ever experienced rising IQ’s and many groups have done just that. Regression towards the mean is very poorly understood by HBD’ers. You descend towards the mean, but not necessarily to the mean.