Did prehistoric conflict hastened human brain's capacity for collaboration?Sure. Experienced rugby players would tell you that, and chimpanzees too, if they were interested in talking more. :)
As you might guess, the distributed return-on-coordination tracks both pattern-recognition skills AND group practice.
If specific neural organs like the cerebellum help mediate smooth coordination among all the muscles & countless muscle fibers of the human body ...
... then what specific CULTURAL ORGANS might - with enough aggregate practice - continuously mediate more return-on-coordination across entire markets, economies, cultures and nations?
You name it. The future's the limit.