But there is no such "observation of lack of conflict in hunter-gatherer bands". At least if you use sensible units, like the proportion of deaths which are due

But there is no such "observation of lack of conflict in hunter-gatherer bands". At least if you use sensible units, like the proportion of deaths which are due to deliberate violence, on which such bands tend to score way above modern society. I think this myth comes from early studies, who wanted to see this, and observed no warfare during the 6 months they spent around 20 people. Later studies asked these 20 to reconstruct their family trees & tabulate how each great-uncle died, etc. (The other possibility is definitional. If we define war as involving thousands of soldiers, then obviously this never happened until societies which could co-ordinate thousands of people arose. May as well define it as involving uniforms & automatic rifles, too.)