jobo
Grandmaster
these are all good points, some of which like progress through war I've made myself.Seeing as the thread has gone anthropological, I'm going to ponder... There'll probably be disagreement, and that's fine.
Advancement from stone to iron isn't/wasn't about collaboration with other peoples - it's about conflict and what that leads to.
To get to sufficient conflict requires a certain set of conditions, mainly land topography and population size (into density).
So, you have small (family) groups of people which tend to naturally grow in numbers until they become a tribe - hunting and gathering is sufficient, but there's going to be small scale conflict with neighbouring tribes over resources (food, women, etc.).
These small conflicts can be utterly devastating for the losing tribe, but the winning side isn't 'safe' because the tribes on their other 6 (say) sides are still going to be competing...
If the land available is restricted (an island, bordered by mountains, that sort of thing) then eventually you'll get one overriding winning tribe.
If there's enough land (Africa, the Americas, mid/west Asia, Australia) you won't. There'll always be another neighbour, or a nomadic tribe coming in.
In the restricted areas, you'll get relative peace. People will breed without constant invasion, population will grow. Tribal chiefs become kings. You'll then get the divergence of fighters and feeders. There's always a chance of an invasion force coming over the mountains, but because it's less likely you get people develop into being farmers and the technology in that area increases - but only if hunting and gathering can't sustain your population.
Once you get to a certain density you look to expand even more, so you send out scouting parties over the mountains or over the water to see what others have. If you want what they have you can trade, or invade.
With the Americas, the Europeans went to explore, then they traded for a while - once they decided that the indigenous peoples weren't much of a military threat (and they could ship sufficient numbers) they brought superior weaponry and tactics and invaded.
It's the expansion that drives weapon and tactic development, and the following peace that drives farming and cultural development.
but the technology first has to be feasible, that is you have,set up an infrastructure o support it, you can use bronze for war or farming, but you first have to set up a way to mine cooper and more importantly tin and then the process for making alloys and a way to work the mettle which is a lit more difficult that copper, there is a whole level of technological development that has to be reached before you can even use war as a driver to progress.
the ancient Egyptian, who were very advanced for their time, struggled to be come a bronze age people, as they had lots of copper but no tin. They did however have the,ability to buy tin, which requires a medium of exchange, ie money or gold and be ale to drag it thousand of miles, which required ships and wheels, they were shipping it in from England amongst other places, they also had a real problem if having no tree to make things like ships and wheels out of, so they shipped those in as well.
with out the ability to build an infra structure those pyramids should still be sand stone
the Inca's and the,aztecs had a real problem with trade, as they kept murdering every one, including millions of their own people. They quite likely murdered the mother of the guy who would invent Bronze