It's a taboo subject for good reason.
Someone saying black guys are stronger than white guys isn't being controversial because we see lots of evidence pointing in that direction.
When it comes to intelligence, it's completely different:
The current measure of intelligence "IQ" was created by Nazis to prove they were a superior race. It's hard to take it serious given the obvious bias at its inception.
A black person that could read would be sentenced to death in the U.S. a hundred years ago.
Blacks in the U.S. are disenfranchised educationally. Some would say the mere facts whites have tried so much to keep blacks uneducated is a clear sign blacks are intellectually superior to whites. Why would a smart person try to keep a dunce from getting an education? That makes no sense.
West Africans have the highest test scores in the world, yes, that includes Asians. These are blacks who have been fortunate enough to have never been enslaved by whites.
Why are the historically free blacks much smarter than their American counterparts? Given white supremacist logic, american blacks should be better since they have a splash of white DNA, but they are significantly dumber than Africans.
I personally think black people are significantly smarter than whites. It's most evident in babies. Black infants do every single thing before white or Asians on average. They start talking sooner, start walking sooner, learn how to use a potty faster, anything you can think of.
Even black Americans are doing pretty well when you factor all that has been done to keep them at the bottom.
Like I said, white people are the ones who don't want to have this conversation. Cause it will force them to admit a truth that makes them very uncomfortable.
Whites might actually be the least intelligent race when you study the different races objectively.