It is surprising that it is so hard for so many to see the reality of race/intelligence, etc. Time, place and circumstances are major contributors. A very few of the very above average of any/all races/cultures escape that. The rest are pretty well chained to it. And the largest links in the chains are forged by fear of an "uknown other." As for mixes and cross-cultural "pollenation" ~~~ in nature, all humans have no problem, and the progeny procreate just fine. Among other animals, as in mules and ligers, for example, nature prevents. In humans the genetics and "parts" are actually quite standardised. Culture and race wars are politics, pure and simple.
BTW, thanks for the reply.