From the waist down:Caucasian women vs Black/African women

[KALABASH]

I have taken sufficient time to make visual survey of the skeletal arrangement around the hips and thighs of both caucasian and black women. I have noted with interest that the hips and thighs of a majority of caucasian women tend to spread sideways whereas those of most black women tend to converge as you move from the waist down. Assuming my observation is correct is there a scientific explanation to this phenomena? And are there positives and negatives associated with either..