Thursday, October 11, 2007

The Thinking Baboon's Baboon

There's really no valid reason, other than religion-guided education, why most people today don't already know that man's closest relatives think and feel many of the same basic thoughts and emotions as we do.

Science, however, is still filling in those reality gaps, and bringing us closer to the truth about what really separates man from the apes - not much at all.

From the New York Times :

...baboons’ minds are specialized for social interaction, for understanding the structure of their complex society and for navigating their way within it.

The shaper of a baboon’s mind is natural selection. Those with the best social skills leave the most offspring.

“Monkey society is governed by the same two general rules that governed the behavior of women in so many 19th-century novels,” Dr. Cheney and Dr. Seyfarth write. “Stay loyal to your relatives (though perhaps at a distance, if they are an impediment), but also try to ingratiate yourself with the members of high-ranking families.”

Baboon society revolves around mother-daughter lines of descent. Eight or nine matrilines are in a troop, each with a rank order. This hierarchy can remain stable for generations.

By contrast, the male hierarchy, which consists mostly of baboons born in other troops, is always changing as males fight among themselves and with new arrivals.

Rank among female baboons is hereditary, with a daughter assuming her mother’s rank.

Baboons live with danger on every side. Many fall prey to lions, leopards, pythons and the crocodiles that in the wet season stalk the fords where baboons cross from one island to another. Baboon watchers are subject to the same hazards. Dr. Cheney and Dr. Seyfarth say their rules are not to work alone or to wade into water deeper than knee high. They often find themselves sitting in a tree with baboons waiting out a lion below. But going into New York is more petrifying, they contend, than dodging Botswana’s predators.

The baboons will bark to warn of lions and leopards, but pay no attention to some other species dangerous to humans like buffalo and elephant. On two occasions, baboons have attacked animals, a leopard and a honey badger, that threatened their human companions. “We haven’t lost any post-docs,” Dr. Seyfarth said.

For female baboons, another constant worry besides predation is infanticide. Their babies are put in peril at each of the frequent upheavals in the male hierarchy. The reason is that new alpha males enjoy brief reigns, seven to eight months on average, and find at first that the droits de seigneur they had anticipated are distinctly unpromising. Most of the females are not sexually receptive because they are pregnant or nurturing unweaned children.

An unpleasant fact of baboon life is that the alpha male can make mothers re-enter their reproductive cycles, and boost his prospects of fatherhood, by killing their infants. The mothers can secure some protection for their babies by forming close bonds with other females and with male friends, particularly those who were alpha when their children were conceived and who may be the father. Still, more than half of all deaths among baby baboons are from infanticide.

So important are these social skills that it is females with the best social networks, not those most senior in the hierarchy, who leave the most offspring.

Although the baboon and human lines of descent split apart some 30 million years ago, the species have much in common. Both are primates whose ancestors came down from the trees and learned to survive on the ground in large social groups. The baboon mind may therefore shed considerable light on the early stages of the evolution of the human mind.

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?

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.

But both chimps and humans use tools. Possibly social life drove the evolution of the primate brain to a certain point, and the stimulus of tool use then took over. Use of tools would have spurred communication, as the owner of a tool explained to others how to use it. But that requires a theory of mind, and Dr. Cheney and Dr. Seyfarth are skeptical of claims that chimpanzees have a theory of mind, in part because the experiments supporting that position have been conducted on captive chimps. “It’s bewildering to us that none of the people who study ape cognition have been motivated to study wild chimpanzees,” Dr. Cheney said.

“Baboons provide you with an example of what sort of social and cognitive complexity is possible in the absence of language and a theory of mind,” she said. “The selective forces that gave rise to our large brains and our full-blown theory of mind remain mysterious, at least to us.”

One interesting thought spawned of reading this story is this : why do we immediately assume that our evolutionary track was for the better of our species? Baboons may be perfectly happy where they are on the evolutionary ladder.

Humans evolved fast, compared to the slow progress of many other species. Some species have barely evolved at all for tens of millions of years.

Maybe we should not be asking what makes baboons similar to humans, but what it is that makes humans similar to baboons.

Perhaps baboons don't have this 'theory of mind' because they don't need it. Maybe they began to develop it, before we built cities, and decided it was more trouble than it was worth.

But the story raises another interesting question : why are we so fascinated by our hairy relatives, but they pay no more than the scantest interest in us?

1 comment:

Anonymous said...

We are mutant chimps who display endless wonder when faced with the fact that other animals have feelings and emotions. We've been conditioned to believe that we are the only sentient beings on the planet, while everything else is animated meat.
The arrogance of the human species never ceases to amaze me. The obvious is only obvious when science recognizes it.