Monday, 5 March 2001

The symbolic species

Listening to:

Chopin, 24 preludes.

Just read:

Terrence Deacon, The symbolic species.

This is a very thorough, and thus rather slow-going, science book about our ability to think symbolically. A consequence of this is that we use language, while no other species does. Symbolic species looks at why and how this might be from a number of different angles.

The book is divided into three parts. The first includes a discussion of what symbolic thought is, and how it can be distinguished from iconic and indexical knowledge which seem to be as much as other species ever seem to use. In this first part, the way in which children learn languages so quickly is also discussed. Noam Chomsky’s theory is that children are imbued with some sort of Universal Grammar that they can easily specialise to the actual grammar that they are exposed to as they grow up. In this way, children make just the right guesses when it comes to language acquisition. Deacon suggests that it’s more reasonable to suppose that languages, which evolve much faster than people do, have evolved to make themselves easier to learn. This was wow moment #1, and the neat thing about this book was that there were quite a few more still to come.

The first part also includes commentary on recent experiments with chimpanzees demonstrating that it is possible to get them to learn symbolic knowledge.

Part 2 was the hardest part of the book to read, because so much of it was about brain anatomy. The pages are overflowing with pre-frontal cortexes (cortices?), cerebellums (cerebella?) and ventricles. Nonetheless it too had its share of wow moments, including a neat discussion of the way in which brain development in primates can be distinguished from development in other mammals, and then how human brain development is different again. This naturally led into a discussion of the Darwinian way in which neurons compete for connections to potential targets when they grow. Because the human pre-frontal cortex is so much bigger (proportionally, and absolutely) than in other apes, it has correspondingly more fingers in all of the brain's various pies. For example, it has control over speech organs (tongue and larynx) in a way not duplicated in other animals.

Part 2 also mentions evidence that basically demolishes the idea that a Universal Grammar might be genetically encoded in our brains. Brain imaging and brain dysfunctions (such as Broca’s aphasia) reveal that language processing of semantically similar tasks (inflecting to past tense, etc) happens in different places in the brain depending on which language is being worked on. In other words, our internal processing depends on the surface syntax of the language, not some deep, universal grammar.

In part 3, there is a great bit of speculative writing about what might have prompted our ancestors to evolve in the direction they did, acquiring symbolic thinking, language and bigger brains. I can’t do the argument justice here, but I will sum it up as “We have language so that we can marry”. Definitely a wow moment. Deacon puts his case against Universal Grammar idea once again, and then finishes by making sensible comments about the “problem” of consciousness.

An excellent, thought-provoking book, though very dense and a slow read.

To read next:

Charles Dickens, Martin Chuzzlewit.