Why HBD

1. The logic of evolution would suggest it

2. The failure of environmental explanations

A) no positive claim, just trying to muddy the waters of hereditarian evidence

B) lotsa money spent to relieve environmental factors with no gains aside from lead reduction. All we have bow are increasingly abstract and unfalsifible narratives for why this is (economc exploitatiob, whte privilege, racism) without anything concrete to tie them to

C) it is a 15 point gap, with the B-W gap. Few environments produce that (as Pinker said with he Jew-White gap)

3. persistence. While it isnt universal, the rank orderings, since there are exceptions it is notable the exceptions have a genetic explanation more readily than an environmental one due to selective migration rather than any environmental factor being identified as being why the situation is different. And some of the exceptions are exceptions, the aforementioned just prove the rule