There are lots of ‘cultures’ in Africa. Swimming is a higher priority in some nations on that continent, especially along the African coasts. South Africans/Zimbabweans might have a lot of swimmers, for instance.
I got called names the first time I mentioned that Asians tend to be lousy drivers, but I was basing that on empirical evidence (my own observations). The name-caller was my own mother, and I was a 16 year-old new driver who was fairly appalled at what I was witnessing out on the roads.
We all have our strengths and weaknesses.