16 March 2006

Beyond belief

Six Impossible Things Before Breakfast: The Evolutionary Origins of Belief, by Lewis Wolpert (Faber)

Let’s say I have a theory about how language evolved in humans. It’s all to do with fruit, you see. Early members of homo sapiens needed to warn each other about what berries were poisonous. Since a grunt and a look of alarm could be misinterpreted as indicating the presence of a tiger, or as a mere ruse to distract the finder and steal his fruit, grunts became semantically differentiated and turned into a handful of words. Then songs could be sung in praise of the banana, and words turned out to be useful for lots of other things too, for example whispering about what Ig and Ug got up to in the cave last night. From there it is but a short hop to Shakespeare.

Such a theory might be more or less plausible, depending on how it brushes up against our prejudices about fruit. But how will we ever know whether it is true? Maybe one day we will make contact with a far older and more advanced alien civilization. They will say to us: “Oh yeah, we checked up on you guys a few hundred thousand years ago. You had only just started talking about fruit, so we thought we’d come back later.” Bingo. But until that happens, our little theory is merely a guess, a just-so story. In particular, there is no reliable way to decide between it and other, perhaps even more compelling explanations. So it goes with Professor Wolpert’s theory, explained in this book, that language, and “belief” in general, evolved because of tool use.

The book is crisply written, and offers a constantly stimulating tour through paleoanthropology, psychology, zoology and human biology. The central idea goes something like this. Though other primates and birds use tools in sometimes quite sophisticated ways, humans are the only animals to fashion their own tools out of separate bits. This must have required the appearance of “circuits” in the brain dedicated to thinking about causality, so that we could hold in our heads the image of the desired tool while making it, and so that we could understand why we wanted the completed tool in the first place. Language popped up to enable us to talk about the merits of different tools, and to make plans for the future. Once we got into the habit of thinking causally, it became natural to want to apply a cause to every phenomenon. If no cause was visible close at hand, particularly for illness and death, we naturally proposed invisible causes, such as omnipotent beings living in the sky.

It sounds plausible, but should we, er, believe it? “The evidence is fragmentary,” Wolpert admits, with charming understatement. There is also counter-evidence, as when Wolpert explains that people in an experiment who were shown non-verbally how to make tools did just as well as those who were talked through the job. More critically, there is a worrying vagueness throughout about the meaning of the central term, “belief”, a concept that has puzzled generations of philosophers but gives Wolpert no pause. Can we really agree that an infant human who pushes blocks around is thereby demonstrating that it has “beliefs” about cause and effect, even though Wolpert denies such beliefs to the cognitively superior adult gorilla? Is a “belief” in God really the same kind of thing, psychologically speaking, as the “belief” that if I drop my cup of coffee it will fall and spill all over the floor?

There seems to be a melancholy hope at large that to explain religion in evolutionary terms will be to explain it away: to show that it is merely a useful illusion. But of course the only people who will be convinced by such an argument are the non-religious. It also invites the riposte, which you don’t have to be a thoroughgoing postmodernist to make, that the edifice of modern physics, too, is a useful illusion: fantastically successful and functional though its theories are, the universe probably isn’t really like that – indeed, an increasingly popular current guess is that it is made of string, which is good news for cats but hard to visualize.

Wolpert’s and other recent books, moreover, show that people are remarkably resilient in holding on to beliefs even when they have been shown to be false or poorly grounded. And it is anyway a central claim of Christianity, for instance, that it is not “grounded” in scientific terms at all – that it depends on faith, not evidence. Moreover, an argument that the brain evolved structures of belief for survival purposes does not stop the Christian from responding that her metaphysical beliefs are a natural fit for those structures, because they are the truth. Wolpert accepts that religion offers “comfort” and foresees its continued existence; yet he ends on a note that combines conciliation with a kind of epistemological threat: “We have to respect, if we can, the beliefs of others, as well as the responsibility to try and change them if the evidence for them is weak or scientifically improbable.”

Six Impossible Things Before Breakfast is essentially made up out of fascinating facts glued together with insistence. There is the occasional brilliantly arresting formulation, such as: “What is amazing is that a mere 20,000 years separate the first bow and arrow from the International Space Station.” On the other hand, countless paragraphs slide cunningly from maybes, possiblys and perhapses to “must have”s. There are some curious blips, as when Wolpert claims that “Dogs […] do not appear in myths” (tell that to Argos and Cerberus), or lumps osteopathy together with chiropractic as examples of dodgy “alternative” medicine.

As for competing theories, Wolpert does at one point mention the popular rival idea that language evolved out of grooming rituals, as argued in Robin Dunbar’s Grooming, Gossip and the Evolution of Language; but he gives us no compelling reasons to reject it. He just prefers his own theory. Maybe you will too. After all, as Wolpert says: “our brain has a natural tendency to find consistent and reasonable explanations for important events”. Hence books such as this one. The aliens will tell us one day.