Graeber and Wengrow are interested in the question of "what is it that causes human beings to spend so much effort trying to demonstrate that they are different from their neighbors" (166)
"the broad tendency has been for human beings to further subdivide [and] it is curious how little anthropologists speculate about why this whole process of subdivision ever happened"
"If any explanation is offered, it's assumed to be an effect of language. Tribes and nations are regularly referred to as 'ethno-linguistic' groups; that is, what is really important about them is the fact that they share the same language. Those who share the same language are presumed, all other things being equal, also to share the same customs, sensibilities and traditions of family life." (167)
and yet "Art and technology from different Eastern Woodland tribes [appear] to have much more in common than material from, say, all speakers of Athabascan languages" (171)
this puts pressure on the idea that "primitive" people are "tiny, isolated communities, cut off from each other and the larger world" (170)