JM: Still in the vein we've been talking about, I'd like to ask about linguistic development (language growth) in the individual. You've employed the concept of – or at least alluded to the concept of – canalization, C. H. Waddington's term from about fifty or sixty years ago, and suggested that the linguistic development of the child is like canalization. Can parameters be understood as a way of capturing canalization?

NC: Canalization sounds like the right idea, but as far as I know, there are not a lot of empirical applications for it in biology.

With regard to parameters, there are some basic questions that have to be answered. One question is: why isn't there only a single language? Why do languages vary at all? So suppose this mutation – the great leap forward – took place; why didn't it fix the language exactly? We don't know what the parameters are, but whatever they are, why is it these, and not those? So those questions have got to come up, but they are really at the edge of research. There's a conceivable answer in terms of optimal efficiency – efficiency of computation. That answer could be something like this, although no one's proposed it; it's really speculation. To the extent that biology yields a single language, that increases the genetic load: you have to have more genetic information to determine a single language than you do to allow for a variety of languages. So there's kind of a saving in having languages not be too minimal. On the other hand, it makes acquisition much harder: it's easier to acquire a minimal language. And it could be that there's a mathematical solution to this problem of simultaneous maximization: how can you optimize these two conflicting factors? It would be a nice problem; but you can't formulate it.

And there are other speculations around; you've read Mark Baker's book (Atoms of Language), haven't you?