Yep, was also going to say Debt. The mUh HuMaN nAtuRe argument is just annihilated again and again and again in that book. There's also a talk on YouTube that Graeber did with an archaeologist and they touch on some more archaeological examples of societies that decimate our concepts of human society, including one group that lived in communistic, orgy-bands in the summer and regrouped into hierarchical society complete with a ruling family heredity and police functions in the winter. Crazy shit. Humans can make pretty much anything work as long as everyone can believe in it enough for it to have its own momentum, and if it doesn't have so many contradictions that it begins to literally rip apart the earth.