Pretty much everything in The Dawn of Everything tbh. The diversity of social organization going back thousands of years, regardless of means of subsistence. The range of conceptions of property, ethics, hierarchy, power, rights, etc.

Particularly interesting in American societies pre-colonization, since it seems the implicit image of them in the popular consciousness is a homogeneous series of small, isolated tribes, consisting of either noble savages or primitive barbarians, entirely ignorant of agriculture. When in reality a good many of them practiced agriculture in various ways, some of which colonizers simply didn't notice because they weren't as invasive as European methods.

Also that agriculture isn't necessary for the development of complex, large social structures, nor does the advent of agriculture necessitate the development of rigid hierarchies and exploitation.

Turns out the agricultural revolution and its consequences weren't a disaster for the human race. Sorry David Quinn.