Originally Posted by Phage

First, if the inter-societal deviation was strong enough (like with other tribes) to merit conflict then I am sure that such actions would be delt with when discovered. While there might be individuals that behaved differently anything "over the line" would have consequences.

Of course not every society will have regular contact with each other. However, unless we are to assume that humans sprung up fully formed from the ground every society had contact with at least one other before they broke away. I am just saying that foundational beliefs tend to preserve themselves even in an isolated society over time. After all a society is made up of individuals which tend to police themselves.

I don't mean to prove anything here, just to point out that it is likely that clothing, social rankings, and other things are probably much easier to change than certain major moral foundations. Don't be too quick to infer universal constants from something that is probably simply preserved from earlier contact.