To prove my point, here is a mystery from Listverse that tells of deadly attack from 1,500 years ago. I guess the hunter/gatherers in this case didn't fair that well.
In 1964, a farmer discovered the remains of three men in a pit grave on the flood pain of Sacramento River. They had died about 1,500 years ago, and all showed signs of extreme physical trauma. One victim had seven arrows embedded in his ribs. Obsidian blades were still lodged in the spines of the other two. This was not a proper burial. Their bodies were splayed out chaotically. There were no grave goods. Experts believe that 560 years ago, central California was a war zone marked by violent territorial battles. Fractured skulls, broken bones, and trophies made of human remains fill the archaeological record from this period.
Isotope analysis of their teeth revealed that the prodigal sons were born and raised locally, but had spent most of their adult life elsewhere—north of the Sacramento River, suggesting that hunter-gatherers had been even more mobile than previously thought. Why had the prodigal sons returned home? And who was waiting for them?
Appears to me that war is just part of the human make-up...and that's pretty sad.
Coffee out on the patio this morning. I have to tell ya, however, it's likely to start getting hot earlier and earlier.