Simple in-group preference is the core of that. It is something we all have in common, no matter how much training it is buried under (which I say with white liberals in mind). Because different races are so very different, that common trait serves as the foundation for different systems from group to group.

Simple in-group preference is the core of that. It is something we all have in common, no matter how much training it is buried under (which I say with white liberals in mind), but because different races are so very different, that common trait serves as the foundation for wildly different system from group to group.