It's stunning how many people seem to forget that there are other countries on the planet that use dollars and weren't involved in Vietnam. No, I'm not making an assumption. The person who posted this is Canadian.
Y'all really need to take a step back and reflect a little bit.
I've heard it claimed social stratification didn't really start happening until agriculture; that's when you see many small residential structures and a few large ones. On the other hand, it allowed for specialization and the pursuit of arts and sciences (at least for the elite).