Research suggests social hierarchies could be a law of nature and bring big
benefits to communities.
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. That s because
the hierarchy can make it easier for any individual to get hold of useful,
reliable information where to find food, say, or how to get a plumber
without having to ask everyone.
One can say that the social hierarchy of ants is rather flat every worker ant
is like any other in social rank, amount of knowledge and so forth while that
of humans is generally both steep (with a strong differentiation of
individuals) and many-layered. We re not unique in having several embedded
layers of structure other primates, elephants and orcas do too. Like us, they
split up into subgroups but like us, these aren t simply little communities
isolated from one another, but are interwoven networks in which individuals
form and maintain social links.
It s within this network that the hierarchy is expressed. That needs little
explanation: we re all familiar with, and probably guilty of, the impulse to
derive status from proximity to power or these days, to celebrity. I went to
school with Bill Gates , or My cousin married a baron , or I once played in a
band that supported U2. Considered as an aspect of biological or cultural
evolution, however, the network should serve a rather more well defined and
valuable function if it is to develop and survive. After all, elephants, so far
as we know, don t have a celebrity culture.
Big man
David-Barrett and Dunbar propose that these hierarchical social networks
facilitate the dispersal of useful information in communities that need to
coordinate their behaviour all looking for food in the same place, say but
which are too big for everyone to consult everyone else. They have devised a
mathematical description of that task in which a community of agents is
interconnected by social links between individuals, each of whom consults its
own personal network in one-to-one interactions to make a decision. It doesn t
matter what exactly the decision is; in the model it s represented simply as a
choice of which direction to face. The question is how long it takes the whole
community to coordinate their individual choices this way.
If everyone in the network is equivalent there is no social hierarchy then
there s an optimal size both of the whole community and of one s personal
network that allows group coordination to be reached most quickly.
If, however, there is one agent in the network who is at the top of the social
hierarchy, who the two researchers call the Big Man , then the status of other
agents depends on how closely connected they are to him.
How does this affect the group s ability to coordinate its members choices?
This depends on what the Big Man knows, since his choice is afforded more
weight than others . The Big Man s closest contacts are also proportionately
more influential, and so on down the social hierarchy. That helps the group to
reach the right collective decision if the Big Man knows best. But if he s
wrong if he s deluded about where the food is, say then coordination can be
very slow. The more likely the Big Man is to be correct, the steeper the
optimal social hierarchy.
This situation isn t just restricted to cases where a Big Man is right or
wrong it could apply to coordination on some arbitrary issue, the existence
of God say. The more the Big Man is regarded as authoritative, the more steeply
hierarchical the society is. Conversely, the more scepticism there is about the
Big Man s opinion, the more egalitarian the society. Is this sounding familiar
yet?
David-Barrett and Dunbar discover a particularly intriguing implication for our
information age. One of the important factors in their model is the cost of
communication: how hard it is to exchange information. It s often suggested
that by lowering the cost of communication, electronic networking will make it
easier for everyone to access information and so will flatten the social
hierarchy. The researchers find that, if there is an initial inequality in how
information is distributed, lowering communication costs counter-intuitively
sustains this steep hierarchy and promotes inequality. There s less incentive
to spread information around: you can just keep on looking until you find it.
If we want to avoid this effect of cheaper communication, they say, then we ll
need ways of compensating for it for example, by greater social investment in
education to disseminate knowledge. The web won t do it for us.