Then it's NOT natural, it's cultural. As a great many reprehensible practices are also cultural, I don't think the fact that something is a cultural practice means that it's good, right, or not subject to question or challenge.
We're digressing... but it is
natural to have a culture. "Natural" does not equal "good". Not having any cultural patterns affecting our actions would be... impossible. Artificial.
I'm just saying it isn't strange that these things happen.