evolutionary psychologist Robin Dunbar is right that evolution equipped human brains to cope with groups of no more than 150 individuals, it follows that communities much larger than this would need new social technologies to hold them together. During the first half of the agrarian era of human history, most farming villages were independent communities with limited ties to neighboring villages and small enough to be held together through traditional kinship rules. Though exchanges of people, goods, and ideas between villages were increasingly important, there were not yet any states,
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