[PapaBear3625]

I suppose its possible that some racial groups tend to be drawn more towards sports than others. It could be a cultural or genetic difference.

The differences in bone density between blacks and whites has something to do with ease of floating.

[Monorprise]

Very interesting, I’ve always known that women could float better i assumed it was just because of their distribution of fat. But it seems bone density also has something to do with it.

[AnAmericanMother]

It's true that higher bone density makes you a "sinker", and that probably discourages some blacks from learning to swim.

BUT - I think it's primarily cultural, not bone density. Most guys tend to sink, as do women who are thin or have fairly heavy frames.

I was a champion sinker as a VERY skinny youngster and teenager, in fact I preferred to swim underwater because it was easier. I'm short with very broad shoulders and a lot of bone, sort of like a mountain pony. Even with the middle-aged spread of a 50ish matron, I still don't float well enough to keep my face free, unless I cram my lungs full of air and adopt the "drownproofing" posture.

But I had my Red Cross Lifeguard cert. by age 15, WSI by 18, just got my BSA cert a few years ago along with my daughter (who is also a natural sinker). It's because our family were always swimmers, boaters, water skiers, etc. and grew up on the water. I don't remember when I first learned to swim.

My daughter's roommate in college was a Latina from San Antonio. There was no culture of swimming where she grew up. She couldn't swim, had never swum, only learned because the college required it for graduation (a good idea in my opinion - GA Tech has had that requirement for years and so did my undergraduate college).