Averages are problematic when you're in a "melting pot".
Example: the "average" pregnancy lasts 40 weeks. But for white women, it's 41.5 weeks.
So for my family, the average pregnancy is 41.5 weeks. THAT is the average, with 50% more, and 50% less.
Because my wife and I are both white. Why would we care what the average gestation is for a negro, or an asian, or an eskimo? It has zero bearing on us.
Might as well concern myself with the gestation period of an elephant.
Why is it problematic? Because the doctor will become "concerned" when your white wife is 41 weeks pregnant -- even though she's right on track for a white woman.
He might schedule an induction, which often leads to a C-section, and could ultimately affect how many children you can have! All because of PC nonsense about "ignoring race" and "we're all the same".