Human Language and Our Reptilian Brain: the Subcortical Bases of Speech, Syntax, and Thought

By Philip Lieberman

Harvard University Press, 221 pp., £26.50

ISBN 0-674-00226-1

Published August 2000

This review published in Times Higher Education Supplement, 12 Oct 2001.
 
 

Lieberman's central message is that "the theory that Charles Darwin proposed can account for the evolution of [human language]". Language is not biologically special, and it is not based on some single, biologically recent development which defines a Universal Grammar and differentiates Man from all other species. Lieberman marshals a diverse range of neurophysiological, palaeontological, and other evidence to argue that language exploits neural mechanisms which evolved to serve other functions (e.g. manual motor control), and some of which reside in the most ancient structures of the brain ó the subcortical basal ganglia, the "reptilian brain" of Lieberman's title.

Lieberman urges that language must be predominantly a learned rather than innate ability. Indeed, even such abilities as walking upright, shared by all adult humans and which one might have supposed to be uncontroversially innate, should according to Lieberman be seen as learned skills.

All this contradicts the fundamental assumptions of the Chomskyan brand of linguistics which held many academics in thrall during the closing decades of the 20th century. Lieberman strongly criticises not only Noam Chomsky himself but, more particularly, his biologically-oriented followers Derek Bickerton and Steven Pinker. Their claims that language behaviour is governed by special-purpose modules of brain structure are demonstrably false, according to research cited by Lieberman, and owe more to misleading analogies with computer science than to empirical evidence. Lieberman sees Chomskyan linguistics as a "worldwide religion" rather than a scientific enterprise; it protects its standing by rigidly isolating itself from contacts with neighbouring disciplines that might come up with counter-evidence.

The irony here is that Lieberman used to be a leading advocate of the unscientific ideology which he now condemns. In a 1975 book, for instance, he argued that the Levallois tool-making culture showed that early Man had acquired the neural basis of transformational grammar, because the two-stage Levallois "core and flake" flint-working technique resembled the two-stage process of creating a deep sentence structure and transforming it into a surface structure. Lieberman now says that "The analogy, in retrospect, was forced" ó surely an understatement.

At the turn of the century, the trickle of apostates from the Chomskyan church is turning into a stampede for the exit, as people who managed to live with the logical flaws of nativist linguistics are coming to realise that techniques such as corpus research and PET and MRI scanning are delivering hard data about language usage and neural processing which render redundant, and often contradict, the purely intuitive and speculative premisses on which that style of linguistics rested. It is understandable that Lieberman wants to get his recantation on record before he occupies the undignified position of a priest without a congregation.

One consequence, though, is that long passages are devoted to unconvincing defences of the precise line taken by Lieberman in earlier writings. Lieberman was best known for arguing from fossil evidence that Neanderthalers lacked human-type language. He now describes this as a misunderstanding, saying that he made only the much more limited claim that Neanderthalers could not produce the full human range of vowel sounds. Yet he still wants to treat this as explaining the Neanderthal extinction. Lieberman cites recent findings that gene-pool boundaries tend to correlate with boundaries between languages, and argues that a distinctive Neanderthal accent would have made them an isolated population, vulnerable to extinction. But the explanation for the gene-pool/language correlation is a fact well known to any red-blooded young man: girls expect some talking first. Contrary to the suggestion of a thousand cartoons depicting club-wielding cavemen dragging women off by the hair, it seems that in the Stone Age as now, a man who could not communicate verbally with a woman was unlikely to mate with her. Lieberman's current claim about Neanderthal vowels, though, does not require dialect differences between Neanderthalers and anatomically-modern Man to have been much greater than those between northern and southern England nowadays, which are no bar to amorous relationships.

Other passages offer an idiosyncratic view of the history of phonetic science. Is it really true that 19th-century research on laws of sound change related to choice between articulatory and acoustic descriptions? Lieberman apparently believes that before Alexander Melville Bell's Visible Speech of 1867, nobody knew how to classify consonants by place of articulation ó though he wrongly attributes that book to Alexander Melville's son Alexander Graham, inventor of the telephone. Lieberman's book is full of errors which a publisher's editor could not be expected to catch, relating for instance to proper names and technical terms.

Despite its shortcomings, though, Lieberman's book serves a useful purpose in drawing together references to recent biological research having implications for linguistics. He rightly urges that linguists ought to be paying more attention to this work than some of them are currently disposed to do.
 
 

Geoffrey Sampson is Professor of Natural Language Computing at the University of Sussex.