The gene in question seems to provide for much finer control over the mouth and the throat, something essential for articulating the sound differences exploited by natural language. It has long been known that teaching chimpanzees to speak is a hopeless task for the simple reason that their anatomy is such that they can't make the sounds used by human speech. The genetic discovery bolsters this very clearly.
However, as is sadly a very common circumstance in science reporting, the significance of findings tends to be sensationalistically overblown, way beyond the significance that the researchers understand the study has.
Case in point: the gene is being touted as a gene for
language. On the basis of a congenital language impairment that has been recently studied, we can at least be sure that the gene is a precondition for human speech. But, a key point is overlooked: speech is only a medium for language, and not equivalent to language. Sure, speech is the primary language medium for most human beings, but the existence of Sign Languages in Deaf communities shows that speech is not a precondition for language. The dateline for the differentiation of FOXP2 puts an upper bound on the emergence of spoken language, but language still could have existed before that in a different medium. Not that I personally have any reason to believe in that, but holes in arguments are, well, holes. To know for sure that this gene is for language in general, we'd have to know whether it also affects sign language. So, until somebody can present us with a deaf person lacking
one of the normal two copies of FOXP2, the question remains open.
And this leads me to my main topic for today. I have a prediction to make: over the next few weeks (and years, for that matter), we're going to see this study cited as supporting all sorts of theories it just doesn't. In particular, the supposed "innateness of human language", which according to its proponents, is supposed to somehow mean something more than the trivial, uncontroversial observation that human children learn to speak in their normal environment, while other species don't, because of genetic and enviromental differences between us and the rest
of the animal kingdom. The currently most famous exponents of these theories in the US currently are Noam Chomsky and Steven Pinker. So, we're going to start
hearing claims like the following: "Recent work in human genetics show that Chomsky's idea that human language is innate are right".
To which I offer two rebuttals. The first one, at which I already hinted above, is as follows: duh. It's hard to imagine even, say, B.F. Skinner thinking that the human capacity for language does not depend on the biological constitution of homo sapiens, which is regulated
by the genetic code. Thus, expect that this utterly uncontroversial idea (that human language depends on the genetics of homo sapiens) will in the nearby future be cited to support a very controversial body of work.
But this the least important of my rebuttals. The more important one is as follows: given the specific claims of Chomskian linguistics, this gene can't be a language gene at all. It fails completely to support the notion that language is innate. If this sounds funny, it is for a reason: in Chomskian linguistics, words like "language faculty" don't quite mean what you might think they do.
Chomsky divides the study of language (in the most general sense) into two theories: the theory of competence (or language faculty, Language Acquisition Device, Universal
Grammar) and performance. The proper object of study for linguistics, according to Chomsky, is competence, which we may define as the system of innate, universal formal properties of languages, which,
crucially, exists autonomously of its actual usage. The theory of competence is about abstract ideas of language present in our minds previous to any experience, and it certainly doesn't concern itself with such mundane matters such as moving muscles in order to articulate speech. That's performance, and to quote one of Chomsky's favorite phrases, "that is not interesting". (If I had a penny for each time I've heard the guy say that...) So, since Chomsky's claims about innateness are about linguistic competence, and the gene FOXP2 crucially
has to do with speech articulation, something's got to give. Either the gene is not about the language faculty, or the competence/performance separation is artificial. (If you ask me, I'd go for the second.)
One further argument of the same point. I mention above sign languages. These are potentially somewhat of an embarrassment to Chomskian linguistics; the theory would look way flimsy if, to account for the fact that there are two primary modalities of language that everybody is capable of learning, there were two separate language
faculties, one for spoken language and one for sign language. The way this is usually turned around is to use the fact in the opposite way: the fact that language exists in more than one primary modality shows that linguistic competence is indeed separate from performance
and medium (speech/signs); the cognitive structures behind linguistic competence is abstract and autonomous relative to those of speech and signing. But this only further shows that the FOXP2 gene then can't be a gene for the human language faculty in Chomsky's sense if it is really
a gene about speech.
Chomsky is certainly no fool, and is very well aware of difficulties of this sort. It is no accident that his favorite language for talking about linguistic competence is in terms of "innate ideas", and not in terms of "genes"; and that he has in the past shown himself unsympathetic to those who would biologize his notion of competence, even to the point where he has said that (a) language is not an evolutionary adaptation, and (b) the properties of competence might be
best explained by physics than by biology. However, more biologically kosher Chomsky popularizers like Pinker fall hard into this sort of problem when they try to find "language genes".
In short, try not to make too much of this finding. And next time you think of repeating the common claim that "Chomsky has shown that human language is innate", stop and think about it for a second. You may be saying something either utterly trivial, or largely preposterous, depending on whether you know what the claim means.