I actually wrote a paper on a similar topic for a sociology class I suffered through back in college. While nothing I read pointed to a direct correlation between race and bass guitar, I did see some interesting stuff about genres specific instruments and their correlation to the race of the musician. If you think about certain instruments that are found in only one or two genres, if those genres are closely related to a specific culture then you see some correlation. I talked about the guitarron, accordion and bazuki in particular.
But bass? Fortuneteller for us all as players, there's not a genre in the universe that doesn't need a good bass line