Sure, it sounds counter-intuitive that humans' genetic adaptation to different environments would stop above the neck, and not impact cognitive processes at all. But consider the following: something something Thomas Sowell something something I Knew A Good One Once.
Guess I should just start walking into large groups of blacks past dark then, since noticing patterns among groups of people is wrong and stupid.
Have you ever lived or worked around nonwhites? Correct me if I'm wrong here, but it sounds like you haven't.
I know that you are not addressing me, but I think that I can lend some insight. I grew up in St. Louis and attended Midwestern colleges. I have lived in the Souh and in Europe (wont get into specifics). I live in Los Angeles, now. I have pretty much dealt with every kind of person there is, except for aboriginals of exotic islands etc.
I am not going to be a

and say that we are all intelligent in our own way ...because it is not true. We are also not the same. Yes we all have human DNA but there are physiological reasons for why Alaskan natives are prone to diabetes, Japanese don't process alcohol very well, and Blacks basically kick everybody's asses in every sport on the planet, except syncronized swimming, shotput and gymnastics.
Believe me, I have encountered more than enough stupid and belligerent Whites and Blacks and Hispanics. I have also met very dumb and ignorant people of all colors, with advanced degrees, working in fields like health care admin, social work, criminal justice, education ... etc.
Basically, it is important to acknowledge that criminality and poverty are not symptoms of racial inferiority any more than high achievements in athletics are symptoms of racial superiority. You could say the same thing about diabetes or skin cancer. Are races that are prone to diabetes inferior? How about whites, who get skin cancer in droves? Are we inferior?
People are individuals. It is foolish to say that the statistical probability of inheriting one particular strength or weakness defines a person as racially inferior or superior.
I think that behind a lot of an individual's or a "race's" strengths and weaknesses have to do with the interplay between the environment and what s/he inherited as in DNA, and the lifestyle and rung on the social ladder they were born into. And a lot of it has to to with attitude, the types of role models they had and access to resources.
So IQ meh - life is so much more complicated than that, sorry.