It would seem, then, that kinship in such cases is really a kind of metaphor for social attachments, in much the same way we'd say 'all men are brothers' when trying to express internationalism (even if we can't stand our actual brother and haven't spoken to him for years). What's more, the shared metaphor often extended over very long distances, as we've seen with the way that Turtle or Bear clans once existed across North America, or moiety sys-tems across Australia.

— The Dawn of Everything by David Graeber, David Wengrow