I’ve just finished reading a book entitled “Grooming, gossip and the evolution of language“ (Amazon link – but no pages to view) by Robin Dunbar a 1996 book written in a highly entertaining style for a lay audience. In my ignorance of the field, I found the book highly entertaining, fascinating and persuasive.
Why might I be interested in it?
Well I heard about it from Anna Gunnthorsdottir’s nomination of it in a popular article entitled “five books that can explain the games people play”. Anna is a behavioral economist who’s website describes her as interested in
- Determinants of cooperation, defection, and reciprocity
- Strategic deception, trust and cheating
- Incentives that increase cooperation
That sounds interesting enough. But I’d like to add that the idea of feedback is of considerable interest to me. For me the subject of human consciousness as interactivity (rather than pure intellection) is a very interesting one. It ramifies through economics particularly Austrian economics though it has not been brought to the fore in the way information and incentives have. Thus neoclassical economists explain markets as dominated by trades of interest between the players. Austrian economists (or at least Hayek) add that trading of information is at least as important.
I think that interactivity the scope for agents in a market to influence each other is just as important. Smith is onto this which was part of my point in naming some previous posts on him Homo Dialecticus. So that’s what got me in. As I read the book I got quite excited. I don’t know how new Dunbar’s theory is, or how well regarded it is in its field. I’ve already found the odd counter-example to his evidence in some book reviews. But given how tenuously our picture of the evolution of language can be anchored to the evidence it seems to me that Dunbar’s approach is very persuasive.
Some readers will have already guessed from my title that there are some obvious parallels here with the Scottish Enlightenment thinkers, not least our friend Adam Smith. The Scotts were into what’s been termed ‘conjectural history’ where they speculated on the rise of civilisation and in particular offered scenarios of the history of humanity driven by particular universal principles. Robin Dunbar’s history of language is pretty conjectural too, though he’s got a lot more evidence to go on that the eighteenth century Scotts.
In any event, the story Dunbar tells rejects the idea that language evolved from warning cries regarding predators. (Some monkeys have ‘words’ in their calls for leopard, eagle etc a fact discovered not that long ago by playing the sounds back to the monkeys and noting that when one call was played [the call for a leopard], they run up trees, and when another call is played [the call for eagle}, they run down them!). Dunbar also rejects the idea that language evolved from the co-ordination of the hunt. Wolves and lions do a pretty good job of coordinating a hunt and they do it without language or particularly big brains.
Rather he argues that language evolved as a means of ‘leveraging’ the work in building primate social relations that was previously achieved by grooming. Grooming evolved he argues from its capacity to build social relationships. Grooming is time consuming and so, like the peacock’s tail, is in the first instance a disadvantage for species that practice it. But it is selected out because species that groom find ways to co-operate that are denied species that don’t groom. Grooming is typically done within close knit groups. Monkeys are not promiscuous with their grooming. To the contrary their grooming is a big investment in each other. So it is used to develop relationships in which each party has a sunk cost which protects against free riding, cheating and capriciousness. If you’ve built up a relationship with someone, you don’t want to trash the relationship and blow all that time you’ve invested.
An important part of Dunbar’s theory came into focus when he was participating in a debate about brain size, social development and the intelligence of different species. The problem was that large brain size doesn’t correlate all that well with intelligence and the size of social groups something that Dunbar sees as key.
Then he mapped the relative size of the neo-cortex in primates and bingo got the graph at the top of this post which shows a clear relationship between this the size of social groups.
. . . BE AMAZED AND LEARN in the next exciting episode . . . how, according to Dunbar’s theory, what made us human is the exact same thing that our trusty guide to life Adam Smith thought was the the thing that makes us human. There’s even a part three!