> .... is there a theory as to why aboriginal and african women don't seem
> to get nipple problems whilst breastfeeding?

To the contrary, it would seem that aboriginal and african women do get
sore nipples.  Whenever I get the chance I have been collecting theories
from different cultures about why women get sore nipples and what they
do about it. My favorite was from Swaziland, where the old belief is that
a snake comes into the bed while the woman is asleep and sucks on her
breast, making it sore.  Obviously snakes are poor at correct latch -
or is it the forked tongue that causes the problem?

It may be that in some traditional cultures the incidence of sore nipples
is lower because their breastfeeding skills are higher, or because there
is less pharmaceutical intervention in delivery.