IQ is largely genetic. I know one black guy that is extremely intelligent. He has a Ph.D. in physics / engineering. He designs medical lasers. He was highly intelligent even as a child.

His dad was an engineer (he ran CAD on a 386 when I was a kid). His mom was a biologist. The brother isn't nearly as intelligent, and in fact, used to literally drool on himself.

Some people win the genetic lottery, some don't, and on average, race is a factor in determining the odds.