There aren't that many sports that girls really like, so the level of competition in the handful that many little girls very much care about, such as gymnastics, is high, requiring years of dedication. 

A friend notes that two African American girls have a shot at making the U.S. Olympic tumbling squad.

They are Gabrielle Douglas and Elizabeth Price.  

Signaling theory: both have normal names, have parents with normal names, and sibs with normal names. 

Steven Levitt and Roland Fryer's study of a huge number of black first names in California concluded that black children who get saddled by their parents with oppositional ghetto names were probably doomed anyway by everything else they get (or don't get) from their parents.

I don't really buy that, however. I'm more of a believer in nurture than Levitt on this. I think nurture works most effectively through class and caste. Unfortunately, the challenges of coming up with a methodology to prove this are daunting.