I apologize, I thought you were referring to non-whites all over the world when you talked about distinct populations being grouped by skin color.

"Black" has been used to refer to indigenous peoples of Subsaharan Africa, many parts of Asia, and Australia. Even some South American groups were once classed as "black."

Well what is the criteria for deciding if a group of people form a "natural group"?

Genetic relatedness, which I hope you'll agree is kind of relevant when discussing genetics.

For example, I could divide the world into 3 races as follows:

Irrelevant; I'm talking about how different groups were actually defined in history, not about the many arbitrary ways which one could choose to split up the world's human population.

Now one could observe that members of Race 1 are more likely to have blue eyes than members of Race > 2 and ask whether the difference is genetic. The answer would be yes even though the races have been defined in a completely arbitrary manner.

One could also observe that members of Race 2 in your scheme are more likely to eat a lot of rice than members of Race 1, and ask whether the difference is genetic. The answer would be no, even if the answer to some other possible question might be yes. People in Sri Lanka plus ethnically Japanese people tend to eat more rice due to history and local circumstances (the agricultural civilizations that most influenced them were rice-farming ones), not innate characteristics that predispose them to a diet high in rice.

I disagree

You disagree that we disagree? I'm afraid I have to disagree with that.

I think it's pretty clear that IQ tests measure intelligence.

Right, as I said: we disagree on that point; if you continue to assume it in your arguments with me you will not be inherently more-convincing because I believe your argument rests on flawed premises. I might be wrong about that, but my own priors do not concur with yours, and you won't get me to update mine by merely reasserting yours.