Tuesday, October 09, 2007

Learning about metaphysics from baboons

Do baboons think and what can we learn from understanding their thought process? There is an excellent article by Nicholas Wade in today's New York Times: How Baboons think (Yes, Think).
Reading a baboon’s mind affords an excellent grasp of the dynamics of baboon society. But more than that, it bears on the evolution of the human mind and the nature of human existence. As Darwin jotted down in a notebook of 1838, “He who understands baboon would do more towards metaphysics than Locke.”
The article mainly talks about research conducted by Dorothy Cheney & Robert Seyfarth. Here is an example of their experiment and what we can learn from it:
In some of their playback experiments, Dr. Cheney and Dr. Seyfarth have tested baboons’ knowledge of where everyone stands in the hierarchy. In a typical interaction, a dominant baboon gives a threat grunt, and its inferior screams. From their library of recorded baboon sounds, the researchers can fabricate a sequence in which an inferior baboon’s threat grunt is followed by a superior’s scream.

Baboons pay little attention when a normal interaction is played to them but show surprise when they hear the fabricated sequence implying their social world has been turned upside down.

This simple reaction says a lot about what is going in the baboon’s mind. That the animal can construe “A dominates B,” and distinguish it from “B dominates A,” means it must be able to break a stream of sounds down into separate elements, recognize the meaning of each, and combine the meanings into a sentence-like thought.

“That’s what we do when we parse a sentence,” Dr. Seyfarth said. Human language seems unique because no other species is capable of anything like speech. But when it comes to perceiving and deconstructing sounds, as opposed to making them, baboons’ ability seems much more language-like.

Assuming that early humans inherited the same ability from their joint ancestor with baboons, then when humans first started to combine sounds in the beginning of spoken language, “their listeners were all ready to perceive them,” Dr. Seyfarth said.

Baboons may be good at perceiving and thinking in a combinative way, but their vocal output consists of single sounds that are never combined, like greeting grunts, the females’ sexual whoop and the males’ competitive “wahoo!” cry. Why did language, expressed in combinations of sounds, evolve in humans but not in baboons?

And a possible answer to this may also have consequences for theories of origin of religion (more on it below):

A possible key to the puzzle lies in what animal psychologists call theory of mind, the ability to infer what another animal does or does not know. Baboons seem to have a very feeble theory of mind. When they cross from one island to another, ever fearful of crocodiles, the adults will often go first, leaving the juveniles fretting at the water’s edge. However much the young baboons call, their mothers never come back to help, as if unable to divine their children’s predicament.

But people have a very strong ability to recognize the mental states of others, and this could have prompted a desire to communicate that drove the evolution of language. “If I know you don’t know something, I am highly motivated to communicate it,” Dr. Seyfarth said.

It is far from clear why humans acquired a strong theory of mind faculty and baboons did not. Another difference between the two species is brain size. Some biologists have suggested that the demands of social living were the evolutionary pressure that enhanced the size of the brain. But the largest brains occur in chimpanzees and humans, who live in smaller groups than baboons.

This theory of mind may also be responsible for our thoughts regarding the supernatural and beginning of religion. A few months back New York Times Magazine had a fantastic article on the science of religion, tiled Darwin's God. Here is a brief discussion on theory of mind in relation to religion from that article:

It’s an odd phrase for something so automatic, since the word “theory” suggests formality and self-consciousness. Other terms have been used for the same concept, like intentional stance and social cognition. One good alternative is the term Atran uses: folkpsychology.

Folkpsychology, as Atran and his colleagues see it, is essential to getting along in the contemporary world, just as it has been since prehistoric times. It allows us to anticipate the actions of others and to lead others to believe what we want them to believe; it is at the heart of everything from marriage to office politics to poker. People without this trait, like those with severe autism, are impaired, unable to imagine themselves in other people’s heads.

The process begins with positing the existence of minds, our own and others’, that we cannot see or feel. This leaves us open, almost instinctively, to belief in the separation of the body (the visible) and the mind (the invisible). If you can posit minds in other people that you cannot verify empirically, suggests Paul Bloom, a psychologist and the author of “Descartes’ Baby,” published in 2004, it is a short step to positing minds that do not have to be anchored to a body. And from there, he said, it is another short step to positing an immaterial soul and a transcendent God.

More on this on another post. In the mean time, read the Baboon article here (also check out the video on the article website of baboons crossing a ford), and read Darwin's God here.