In other words, it’s nuture and not nature
The idea that variation in intelligence between individuals is more to do with parental environment rather than genetics is a historical curiosity.
The debate is whether intelligence is 50% or 70% inheritable. All attempts to account for environmental factors can get it down a few points but not by much.
Identical twins raised apart are highly similar; identical twins raised together are more similar than fraternal twins raised together; biological siblings are far more similar than adoptive siblings raised together who are no more similar than two individuals chosen at random.
The heritability of intelligence increases with age typically rising to about 80% - Yes you do turn into your parents!
It would be strange if average IQ didn't vary between different ethnic groups but so what? We need to accept the science and find other reasons to treat everybody with dignity and respect.