In one of his most-quoted journal jottings, Charles Darwin suggested that "he who understands baboon would do more towards metaphysics than Locke". By "metaphysics", he probably meant by something slightly different from the way we would use the term today, namely the fundamental architecture of our processes of knowing and thinking about the world. In other words, given that our mind is of natural origins, one could contribute more to understanding it by comparative, scientific study of the minds of related species than by pure speculation and debate. This is a bold and controversial thought today, let alone in 1838. One suspects that the "baboon" in the sentence is rhetorical; Darwin probably meant creatures related to humans more generally rather than one group of African terrestrial monkeys in particular. Nonetheless, as Dorothy Cheney and Robert Seyfarth, who are famous for their earlier work on vervet monkeys, have spent many years studying baboons in Botswana's Okavango delta, they are uniquely qualified to take up Darwin's challenge in a literal manner.
The content of the book can be roughly divided into three areas. First, it gives us an insight into the world of the baboon, drawing on decades of careful observational and hormonal research. This part is a kind of anthropology of the baboon world. The world that emerges is that of Shakespeare's history plays; feuding clans (though for baboons, clans are matrilineal, whereas the Yorks and Lancasters are patrilines); males rising often violently up the status hierarchy, only to be displaced in their turn; females attempting to protect their interests and their offspring from the threat of infanticide and loss of status. The primacy of the matriline aside, this is a deeply familiar matrix to anyone who reads human history.
This material would justify the title "Baboon Life" or perhaps even "Baboon Politics", but scarcely "Baboon Metaphysics". The metaphysical content comes in the second and third planks of the book. The second plank is an attempt to understand what it is that baboons know and think about the social world in which they live. The authors report on years of ingenious experiments they and their collaborators have carried out exploiting baboon vocal communication. Baboons reliably recognise individuals from their calls, and also recognise the types of interaction that the call represents (submission, domination, reconciliation and so on). By using recordings of calls harvested from natural interactions and then played back under novel circumstances or in novel combinations, and measuring the listeners' responses, the researchers can probe what the animals expect and infer about the dynamics of the social drama going on around them. The results show that baboons are aware not just of their own status in the group, but of the relative statuses of everyone else, and can track changes in status and in friendships, understand kinship relations of others, and predict what positions third parties will take in disputes involving their families and allies.
In this respect, the book can be seen as a detailed fleshing-out of what is known as the "social intelligence hypothesis", the idea that the reason that primates have such large brains is the need for computing power to deal with the complexity of the social aspects of their world. Clearly, the social cognition of baboons is impressive; there are charming stories of tame baboon goatherds who can reliably place 20 different lambs with the right mothers. On the other hand, there are limitations, with diverse evidence suggesting that baboons are not fully capable of adopting the perspective of another individual.
The third thrust of the book concerns the similarities and differences between baboons and humans. Although human social cognition is clearly much more sophisticated than that of baboons, this sophistication is a continuance of the trend within the primates, not a qualitatively different direction. There is a convincing discussion of how the need to represent social information internally to the mind might provide the prerequisite representational system for human language to develop.
Cheney and Seyfarth have developed a deep understanding and ingenious methodology that they have brought to bear in their work with baboons, which in turn highlights the lacunae in our knowledge about the minds of other species. They detail memorable stories of baboons working as signalmen and mechanics' assistants that remind us of their kinship to us. Above all, their book gives us a tantalising picture of how a close relative is so like us in its concerns, and so unlike us in its desire to talk about them.
Daniel Nettle is reader in psychology at Newcastle University.
Baboon Metaphysics: The Evolution of a Social Mind
Author - Dorothy L. Cheney and Robert M. Seyfarth
Publisher - University of Chicago Press
Pages - 358
Price - £16.00
ISBN - 9780226102436