Even that wouldn't work. Here's why:

Read about Jane Elliot's brown eyes, blue eyes experiment. Cliff notes version: A school teacher tells her class that the brown eyed kids are better than the blue eyed kids, puts collars on the blue eyed kids, and sees what happens. Very, very quickly, they take on these oppressor vs. victim roles. Suddenly, she's noticing things like the blue-eyed children who used to be smart couldn't perform well. Brown-eyed kids were spelling words she knew they couldn't spell.

Simply being a black child in a white-dominant classroom is enough to potentially throw those kids off on the tests. Could this be a problem for a predominantly black school in a white-dominant country? Or a predominantly black country in a white-dominant world? It is argued that America is not a white-dominant country and that's true if you look at the population statistics. But that doesn't mean everyone's updated their attitudes or that the social structures have really changed. :/

One interesting thing I want to note here is that I have read that Chinese people feel a sense of pride about being "the first people." I don't know whether that is a common attitude in China, but IF it is, and IF these IQ tests are actually accurate (which I have already stated some serious criticisms about) perhaps the difference is the way that the races perceive their lot in the world.

Also, I hate to do this to you because if I were on the receiving end I would feel really bad, but I can't not say it now that I've seen it:

Why do we have to stick to comparing black foster kids with white foster kids, as if there are no black children in middle class families to research? Michael Jordan, for instance, made it well beyond the middle class. I've seen black people working middle class jobs, and met a black guy recently who makes a lot of money working in IT. It's not like they aren't out there.

I hope you don't take it too badly... we all come here because we want to remove our bias. That's a respectable goal. If you see any of mine let me know. (: