I feel like I'm stating the obvious, here, but it's the nurture, not the nature.
For instance, it isn't that Europeans are genetically superior to Africans; Simply that they have had (on average) better access to education, funding etc.
As for the Jews, it's very much tradition for them to keep within certain (high-paying) trades and routes of education. Such an ethos lends itself to having more "successful" members of a race - but it does not necessarily deem them naturally intelligent.