I don't really have anything like this developed right now, since all the cultures in mine trace their roots to one larger culture that split after a devastating war that shattered a part of the main continent and flooded the giant central lowlands. So, their base cultural assumptions and the like are all the same.

This concept is a very interesting one.... I love creating disconnects between various cultures in this way. I think the most obvious ones are the antipathies felt by the various tribes in my world to the habitats of the other tribes. The Ttekarx, for instance, who inhabit the marshy regions, cannot bear the plains, and have dozens of reasons for it. The Haharu, plains folk, are the opposite. And so it goes throughout all the tribes. And all of them have extremely different ideas and impressions about the various aspects of nature. The Ttekarx tell stories about the stars being lamps of the gods. The Ssexane know what the stars really are, to as great a degree as they can, and use them for navigation. The Rwemun attach religious and superstitious meanings to them. And this goes on for all of the tribes, over everything, practically. It's great fun. Especially when people from different cultures get into miscommunications because of it – insulting each other without meaning to, etc.

The only thing that I can think of where two of my built cultures have a different perspective on something is learning. The Nalycian nobles prize learning and knowledge, while the Athulian nobles consider learning other than that necessary for warfare to be a waste of time. I should probably do some more thinking on this, since my novel contrasts the two cultures extensively.

*Nods* I'm guessing that after a long period of time things might start to develop in different directions if the cultures are cut off from each other, but if they are still somewhat connected, then maybe not so much.