Why Chomsky Is Wrong About the Evolution of Language
Chomsky’s contention has little or no genetic support.
Posted Jan 27, 2015
Recently, Chomsky and colleagues (Bolhuis, Tattersal, Chomsky, & Berwick, 2014) published an article entitled How Could Language Have Evolved? The chief irony of the title is that its authors essentially argued that language did not evolve. According to their Strict Minimalist Thesis, language appeared suddenly about 70,000 to 100,000 years ago, and they claim it does not appear to have been modified since. In their minds, modern human language is so special and so unique that animal communication studies are useless in understanding the human faculty of language and also useless are studies of auditory and vocal learning. As they reason, auditory and vocal studies may be useful for understanding speech, but not language. Hauser, Chomsky, and Fitch (2002) define language in two ways: FLN = faculty of language in the narrow sense (only humans have it), and FLB = the faculty of language in the broadest sense. The latter may be used to refer to animal communication. Thus, FLN is a subset of FLB.
Chomsky and colleagues are clever and slippery, in my opinion. Chomsky’s colleagues rely on Chomsky’s absurd contention that language appeared “whole-cloth” in one human presumably by one gene (or genetic combination?) about 70,000 to 100,000 years ago. This resulting unique form of communication was so amazing and so wonderful that it swept through the extant human race, and voilà, here we are with a hierarchically structured, cognitive system that unites us all. First, Chomsky’s contention has little or no genetic support. One gene does not suddenly cause hierarchically structured language. But that is one of their clever and slippery arguments: It is possible that some genetic mutation altered FLB at that time, but these authors rarely, if ever, invoke anyone else’s cognitive theory (e.g., working memory, a predominant cognitive model for over the past 4 decades). Further, because Chomsky has pronounced that language did not evolve, then it logically follows that it could not have been subject to natural selection. Note well that Chomsky has not elaborated upon why language was not subject to natural selection, and further, he proffers the cryptic argument it did not evolve for communication purposes. Chomsky and his colleagues do propose that it might have developed for spatial navigation but with little or no elaboration (see Hauser, Chomsky, & Fitch, 2002, and Fitch, Chomsky, & Hauser, 2005).
Of course, another major irony of Chomsky’s reasoning is that part of his fame developed in the early 1970s for criticizing Skinner’s theory of behaviorism and for the latter’s reliance on empirical studies and observations. Meanwhile, Chomsky eschews empirical studies of childhood language acquisition and ignores virtually all neurophysiological studies of language’s foundations. Interestingly, at that time, he endorsed the use of neurophysiological evidence for which he said Skinner lacked while his current hypotheses lack such evidence. In fact, in the Bolhuis et al. article, Figure 2 (“A crude plot of average hominid brain sizes over time”) combines in a single form, Neandertal brain size with Homo sapiens. I suppose we must forgive such a superimposition because the figure is labeled “A crude plot….,” but nonetheless, it seems unforgivable since paleoneurologists have repeatedly shown not only about a 10% bigger brain in Neandertals than extant Homo sapiens but also parietal enlargement in the latter but not the former (e.g., Bruner, 2004, 2010). That there is empirical ‘neurophysiological’ evidence for the parietal lobe involvement in spatial working memory, number appreciation, sense of self, and many other higher cognitive functions seems to me very consequential.
Even the Bolhuis et al. evidence for symbolic behavior about 80,000 years ago is questionable. Beads and engraved ochre may indicate symbolic thinking but a simpler hypothesis is that they marked something. Whether they were used in a one-to-one correspondence to count something or the beads signified a group allegiance, they are provocative but to claim they are ‘indirect’ evidence for language’s sudden appearance is misleading and disingenuous. However, my arguments would be disingenuous if I simply criticized instead of offered alternatives. They are as follows:
There once was FLB. This broad form of communication probably evolved for social purposes, especially in primates about 80 million years ago. Their vocal communications probably helped them compete with other animals for nutritious fruits, which helped fuel bigger brains. When the australopithecines (“Lucy") made the transition to full terrestrial life about 2 million years ago (becoming Homo erectus), bigger brains were again naturally selected for their social uses in bigger groups (i.e., the social brain hypothesis) and for extracting more resources from the environment (i.e., the extractive foraging hypothesis). Then, a genetic event (epigenetic or otherwise) did occur in the recent ancestors of Homo sapiens such as Homo idaltu around 200,000 years ago. This genetic event was small but significant and may not have occurred directly in the faculty of language per se but in some important and related cognitive mechanism, such as working memory capacity (see Baddeley, 2002; Wynn & Coolidge, 2010). My colleague Thomas Wynn and I called the result of this genetically influenced event ‘enhanced working memory (EWM).’ However, admittedly here’s where we get slippery. We have proffered a number of possibilities about its nature. For example, did EWM occur because phonological storage became larger, i.e., we could hold more in our acoustic memory? What would be the latter’s advantage? For one, it might allow for recursion, that is, embedding a phrase within a phrase. Second, it might have occurred in the visual-spatial component of working memory. Given that there’s empirical evidence for recent parietal lobe expansion and the latter’s demonstrated role in visual spatial working memory, this hypothesis also makes sense. Or did this small but significant genetic event about 200,000 years ago affect general, non-domain specific working memory capacity? Unfortunately, it seems very difficult to measure working memory capacity outside a specific domain. But that’s another story….