Baboon Metaphysics: The Evolution of a Social Mind

  • Dorothy L. Cheney &
  • Robert M. Seyfarth
University of Chicago Press: 2007. 358 pp. $27.50 0226102432 | ISBN: 0-226-10243-2
Understanding how baboons interact could throw light on the origins of the human mind. Credit: M. BOTZEK/ZEFA/CORBIS

There are few guiltier pleasures than watching reality television such as Big Brother, in which young people interact with each other in confined spaces. Viewers relish seeing each individual trying to push forward their own agenda through alliances and disagreements, sex and friendships. How did we become both agents and voyeurs of such status-striving?

In Baboon Metaphysics, Dorothy Cheney and Robert Seyfarth explain that our social reflexes evolved from our group-living primate ancestors. They explore what sort of intelligence is required to navigate the intricate social landscape that baboons live in. Is it based on a complex calculation, a system of innate rules that are applied to specific contexts? Or is it based on simple, implicit rules governed solely by learned associations?

The book's title comes from a line that Charles Darwin jotted down in his 1838 Notebook M: “He who understands baboon would do more towards metaphysics than Locke.” The quotation reflects the tension between two philosophical schools of thought on the origins of knowledge. One, espoused by John Locke, suggests that the mind acts simply to associate events that have been joined together by proximity and repetition. The other, represented by Immanuel Kant, suggests that perceptions exist a priori — that is, the mind is not a blank slate — but require experience for their expression. Darwin, a witness to the stereotyped behaviours of numerous animals, could not abide Locke's view and sought an explanation of the mind that combined the roles of innate tendencies and experience. This tension pervades this wonderful book on the social intelligence of non-human primates and what they might tell us about the evolution of the human mind.

Few are in a better position to address the question than Cheney and Seyfarth. They have spent many years observing and conducting behavioural experiments on vervet monkeys in Amboseli National Park, Kenya — the subject of their earlier book, How Monkeys See the World (University of Chicago Press, 1990; see Nature 350, 565; 1991 for review), and now work on baboons in the Okavango Delta, Botswana. They share this experience with us in a lively and engaging manner.

First, they lure the reader in with wonderful anecdotes, such as Ahla, the goat-herding baboon, who spontaneously recognized the relationships among her goats, and compulsively reunited any lost baby goats with their mothers. Or there's the orphaned baboon who, when separated from his group, cleverly spent a few days under the protection of vigilant groups of impala, and later vervets, before a jubilant reunion with his fellow baboons.

Next they provide experimental evidence to tease apart what baboons really know about social relationships and how they use this information to get ahead in the world. For example, playing back a sequence of calls that mimics a dispute between individuals reveals that eavesdropping females are acutely aware of who is fighting and whether it involves their family. More transient social relationships, such as sexual dalliances, are also closely monitored. Playing back a recording of a male's grunts with a female's copulation call reveals that hopeful bachelors are acutely aware of another male's consortship, or when a female is making a cuckold of him or when a consortship has ended.

Cheney and Seyfarth argue that this complex social knowledge cannot be the result of simple associative learning alone, particularly because it does not necessarily result in immediate rewards or benefits. They posit, for example, that baboons learn about hierarchies through observing the close associations between certain individuals. The authors suggest that the number of dyads and triads to learn is too vast, and that putative metrics, such as rates of aggression, do not unambiguously specify the nature of a relationship because they occur with similar frequencies both within and between different family groups. Furthermore, baboons belong to many different social classes concurrently — for example, a female can be a member of matrilineal group, a friend of a high-ranking male, and/or a friend of other females outside her kin — and class membership is liable to change.

What, in addition to associative learning, is necessary to explain baboon behaviour? Cheney and Seyfarth suggest that evolution selected individuals who are predisposed to recognize other individuals' ranks and social relationships to form rule-governed classes. They propose that this predisposition is innate and similar to the human predisposition to learn language. Unfortunately, this is not a very satisfying argument as it leaves much of a baboon's behaviour to some mysterious innate mechanism. One possibility not mentioned by the authors is that the baboons' social knowledge is based on statistical learning, in which relationships can be implicitly learned through the increased probabilities that certain dyads or triads are seen together or that certain sequences of calls are heard with greater frequency than others. This mechanism is different from typical associative learning in that it is rapid, does not require reward and can be used to generate rules. Under this scheme, any explanation of baboon social intelligence would be completely interdependent with the structure of the current social group and the interactions therein.

We reflexively attribute minds like ours to non-human agents. Cheney and Seyfarth are acutely aware of this and, with their clever field experiments and careful observations, they address important questions regarding the evolution of social cognition without succumbing to the almost irresistible temptation of anthropomorphizing. Their enthusiasm is obvious, and their knowledge is vast and expressed with great clarity. All this makes Baboon Metaphysics a captivating read. It will get you thinking — and maybe spur you to travel to Africa to see it all for yourself.