The custom of sharing is very common in aboriginal societies. One of my professors in university lived up in the Arctic with the Inuit. He noticed that if they saw something they liked (eg a nice pair of gloves they asked and expected to be able to use them). This is probably a very useful custom in nomadic lifestyle. Which reinforces some of the comments made above.

The second and more subtle point though is that this thread and many others for instance the "coon songs" discussion tend to involve us as a society (with our own present values) looking back and making value judgements on previous generations. Historians refer to this as "presentism". In the current climate we make value judgements about Europeans and their treatment and misunderstanding of the natives. The fact is that people have migrated for thousands of years and displaced other people. We can look back and make judgements about (slavery for example) when it was very common for native tribes to raid each other and capture slaves. In the same way our values when applied to the practice of human sacrifice in south and meso american cultures is is just as irrelevant as it is to look back on what Europeans did.

Some more terms which have entered the lexicon. White man speak with forked tongue. Let us bury the hatchet. And skunk and chipmunk are all words that come from native or first nations north american