"Barring Pathology": Nature vs. Nurture just got personal!

Fruit tree in December: Are these lemons?

On my academic website, under Current Research projects, I've written the following:

No-one with young children, and an appreciation of human history, can reasonably prefer social over biological determinism, unless they are incredibly optimistic about society, and I'm not...

The line was written with regard to three closely-related 'big questions' that most of us professional linguists care about: (i) how much of Language is innate?; (ii) are there Language Universals, or can languages 'differ from each other without limit...and in unpredictable ways (Martin Joos)?'; (iii) does the language you speak materially affect the way you think? At first sight it might be thought that the first two questions are different ways of asking the same thing: if significant aspects of language are innate, then there must be Universals; conversely, if languages can vary without limit then it would seem that no aspects of Language can be innate. Now, I've argued elsewhere (in print, and in the blogosphere) that this is wrong, that one can well be a nativist about Language with a capital L, while arguing the toss about language universals. (I also believe—as a typical academic—that the answer to the third question is 'Yes and No', though more 'No' than 'Yes' (I hope!)). But none of that is greatly important.

The reason for bringing it up here, on this family site, is that what I research and teach just got personal. For I've realized that, like most nativists (see Steve Pinker's discussion of this in his Blank Slate book), I'm hopeful about biological determinism because I've only ever looked at typically developing children. Nativist introductions to language development argue for the innateness of language on the grounds that typically developing children acquire their native language perfectly, with astonishing speed and accuracy (compared, for example, to the usually abysmal performance of adult second language learners). And in almost all of these texts, there is some reference to atypical children: the phrase that one frequently reads is "barring pathology". The following quote from James Hurford is representative, and I've trotted it out myself in previous work (see directly below):

All human languages have these properties which must be mastered in a few years by the child; and, barring pathology, children achieve mastery spectacularly well (Hurford, 2008 BBS)

The goal of determining the precise nature of Universal Grammar is externally constrained in two ways. First, as we have mentioned, there is the fact that first language acquisition is uniformly successful (barring pathology) and that it is also astonishing rapid; by the age of four at the latest, children show clear evidence of having acquired all of the major grammatical properties of their particular language (Duffield, 1995).

Barring pathology. A simple dismissive adjunct clause, signifying "we've got those cases out of the way; now, we can get on with the main business". All very well until your own child belongs to that small minority: for Justin is a pathological case (as literally defined) but he is also our baby. So now I wonder: should I still prefer biological over social determinism?

The shrine near Julian's nursery: time for a quick prayer

The right answer to this is not yet clear: like the symptoms of Justin's condition, it is something that will emerge and evolve over time. One thing has changed, for certain: I'd better start becoming more optimistic about what the environment can do to improve his life quality; I'd better hope that social and educational services can be forces for good, and can help us to make a real difference to his life, because pessimism about these things will not help any of us. Yet, at the same time, my nativism is also a source of optimism: for though the general prognosis of (genetically determined) moderate mental retardation gives us sleepness nights, there is a small amount of research out there—some by my friend and colleague Helen Goodluck—that suggests that understanding of complex language is relatively spared in high-functioning DS (even if speech remains a great challenge). So, there is hope in this idea, after all.