April 03, 2005

The sound of one hand waving*

On April Fool's Day, Terrence Deacon, Professor of Biological Anthropology and Linguistics at the University of California, Berkeley, gave a talk here at the University of Michigan on the evolution of language. If the talk was meant to be self-contained (as in, you needn't have read all his writings in order to follow the argument), it was remarkable for the complete lack of support offered for the main thesis.

Early in the talk, Deacon presented a handsome Power-Point slide with pictures of various plants that display Fibonacci spirals -- daisy petals, a pine-cone, things like that. He said that, although there's a genetic component underlying these structures, the spirals themselves come about through self-organization: they are not directly encoded in the plant genomes, but arise in each plant because they're useful (for instance for ensuring that the maximum amount of sunlight will hit each leaf) and because their shape is mathematically determined. I haven't studied botany since I was an undergraduate, eons ago, so I will assume that his story about the Fibonacci spirals is right. In most of the rest of the talk he discussed other non-humans, especially finches, and the complex relationships between genes and behavioral patterns (like finch songs).

Finally he returned to people and argued that, although human language has a stage-setting genetic component [I can't guarantee that that's a precisely accurate paraphrase, but it's not too far off], innate universal grammar is nowhere near as rich as it's often claimed to be. Instead, like the plants with their self-organizing Fibonacci spirals, many or most of the universals in human language are to be attributed to -- and here I quote -- "social-semiotic self-organization". In one short sentence he mentioned a couple of examples that, he said, support this claim, but in the talk itself he gave no shred of evidence to justify the analogy to the mathematically elegant Fibonacci spirals. It wasn't even hand-waving -- at most one hand waving, or maybe just one appropriate finger. I wanted to ask what could possibly constitute non-circular evidence for such a claim, but I couldn't, because he announced at the beginning of the question period that he would recognize only in-group members in the discussion period. Well, O.K., he didn't put it that way: he said he'd call on "you guys at the back because I know you have to leave soon". So did the rest of us, unfortunately (or anyway I did; possibly others stayed and even got to ask questions after the favored few were finished with theirs).

A not totally unrelated thought: I'm beginning to wonder about biological anthropologists who talk about language. A year or two ago the local set invited a speaker who proposed that the Ur-human language probably had clicks because (a) humans originated in Africa, and (b) clicks occur in a few African languages, and (c) there's a lot of genetic distance between some groups who speak click languages, and (d) clicks can't arise spontaneously, and (e) the chances for borrowing are vanishingly small because the groups aren't all that close geographically. (The huge problem here is with premises d and especially e.) Most linguists would hesitate to make pronouncements about biological anthropology; too bad the reverse doesn't also hold.

A final thought: maybe the late-19th-century members of the Société linguistique de Paris got it right when they banned research and publication on the evolution of language: the ban was meant to suppress wild unfounded speculation about language origins. Now that the topic is popular again, there still seems to be a lot more chaff than wheat.

A post-final thought: No, I don't think Deacon's talk was an elaborate April Fool's Joke. I did consider that hypothesis, but on the evidence it had to be rejected.

*Acknowledgment: The title of this post was suggested by fellow Language Logger Philip Resnik, who was visiting the Ann Arbor corner of Language Log Plaza on Friday, and whose fascinating demo and excellent talk entirely did away with the bad mood that Deacon's talk left me with.
Disclaimer: Philip's title suggestion does not, of course, mean that it'd be fair to blame him for any infelicities, a.k.a. stupid mistakes, in this post.

Posted by Sally Thomason at April 3, 2005 03:54 PM