Intelligence has a genetic component. Every single test we have that attempts to measure intelligence that we've checked for heritability shows that intelligence likely has a generic component. Furthermore, we know that some species are more intelligent than others. Given the demonstrable existence of Darwinian evolution, this implies that some populations of a species are more or less intelligent than another because that's a requirement for a speciation event that results in a species that's more intelligent than its cousin species.

Anyone who says otherwise is likely allowing their ideology to cloud their judgement.