So, is slavery responsible for the athletic performance of African Americans?

[Nikia]

52. I think a lot of it is cultural

At integrated high schools, black students seem to be encouraged to sprint while white students are encouraged to do distance. In schools where that has been a longstanding tradition, it may become part of a social role discouraging many students from crossing the color line. I lived in semi rural Northern Ohio where whites were a large majority at most schools. One of the interesting things was that when one area black or Hispanic student ran and excelled at cross country or distance that several others followed rather than staying in the sprinting ghetto. It seemed that happened in other areas of the state with sprinting for whites also.
I don't think that we should discount the fact that there have been some geographical areas of good competition. Once you get more than a few athletes excelling at a high level that are competing against each other all the time, it brings the level of competition up in general. There are very few young athletes that can reach a high level of performance without close competition. Excelling at the high school level, enables them to get Division I scholarships at colleges and/or conferences where they will compete against world class competition. In other countries, there might be alternative racing circuits that also compete at a high level of competition, but if there aren't it is hard to reach a world class level while everyone else is way behind.