“We hold these truths to be self-evident, that all men are created equal”, declared the signatories of the American Declaration of Independence, but the slave-owning Thomas Jefferson did not seem to think they need stay that way. Indeed, if there’s one characteristic shared by almost every human society, it is inequality: the existence of a social hierarchy.
Humans aren’t alone in that. But in an ant society, at least you know where you stand: you’re either a queen, a worker, or a male, fit for nothing but reproducing. Humans, in contrast, have complex, many-tiered and overlapping hierarchical structures: only we seem to have developed the exquisitely nuanced caste of the local government officer. And though some might dream of utopias in which no one has any more power or importance than another, these social hierarchies always rear their head eventually.
Is this, in fact, a law of nature? A paper in the Journal of Theoretical Biology by economist Tamas David-Barrett of Birkbeck College in London and anthropologist Robin Dunbar of Oxford University seems to say so. It shows that the existence of a social hierarchy in a community can be adaptive, in the sense that it helps the community to function more efficiently.