“Why is it that blacks still lag far behind Asians, people from India, and pretty much everyone else?”
Could it be “The Bell Curve”?
If I can find the article I would post it. A few years ago I read a discussion of the effects of migration on several countries over the last several centuries. There was a brief discussion of the effects of imported slaves during the late 1600 - early 1700 into the USA. The bottom line was that when the slave traders were scouring the African west coast for blacks, it was not the smartest or the quickest blacks that were caught. The inference was that the bottom half of the gene pool was the initial seed for the black population in the USA.
Kind of a brutal assessment but IMO not without it’s merits.
Could it be The Bell Curve?”
No, it is called social and cultural evolution. We spend several thousand years slowly progressing into a modern advanced society by learning the lessons on how to adapt, and build a modern society. that is how long it took to go from an aboriginal society to what we have now(on your own). They only have a few hundred years. But,since they were taken into a modern society (regardless of the circumstances) they have had the ability to emulate and adopt and many of them have they have caught up completely. Others have not both circumstances are completely predictable.