Language, evolution, and the brain (review)

In recent years it has become increasingly evident that linguistic structure can never be fully understood without some appreciation of how it relates to brain structure. As one who has been convinced of that fact for a long time, I was immediately attracted by the title of this book—a collection of papers resulting from a seminar hosted by the International Institute for Advanced Studies in Kyoto in 2007. Actually, this book can be seen as a companion to the editors’ first volume, Minett & Wang 2005, which weighs in at 538 pages and includes contributions by, among others, Murray Gell-Mann on language and complexity, John Holland on genetic algorithms, and Bernard Comrie on creoles. Together these two volumes make an impressive statement.

The title of this collection activated an assumption in my mind that the papers would be concerned with the evolution of language in relation to the recent evolution of the human brain: for example, how it is that developments in cortical structure led to development of linguistic complexity, and how development of linguistic complexity over the period of some hundreds of thousands of years led to structural changes in the brain. As it turns out, only one of the eleven papers in the volume actually treats this topic directly: Ch. 8, ‘Brain evolution relevant to language’, by P. Thomas Schoenemann. It is a fine paper that more than makes up for my disappointment that some of the papers did not fit the expectations I had based on the title of the volume. This is not to belittle those papers. On the contrary, some of them are not only very interesting and informative, but they in fact turn out to fit the title if we interpret it more loosely.

In Ch. 2, ‘Sounds like teen spirit: Computational insights into the grounding of everyday musical terms’, Jean-Julien Acouturier makes the point, in the context of music perception, that what we perceive depends to a great extent on what is already in our minds. The point is well illustrated by my perception of the title of this volume and the resulting expectation. It may be that some others will find the title not so inappropriate. After all, the term ‘evolution’ has a range of meanings. For example, it can include the process of grammaticalization, as in Shibatani’s fine paper (Ch. 3). One might suppose that the context provided by the presence of ‘brain’ in the title would tend to activate the more prototypical interpretation of ‘evolution’ that registered in my mind, but that effect seems not to have occurred in the thinking of some of the contributors as they prepared their contributions. No matter—they are interesting and valuable papers anyway, so I shall not quibble.

Only four of the eleven contributions bring the brain directly into their discussions: Ch. 4, on the organization of the lexicon, by Ogura, notable in its application of network theory to lexical structure; Ch. 8 by Schoenemann; Ch. 9, by Oztop, on mirror neurons; and Ch. 11, by Kay and colleagues, on the influence of language on color perception. Also, Mufwene’s contribution, while not going into details about the brain, does have it in the background of his treatment of the evolution of language.

As mentioned above, Schoenemann’s paper, ‘Brain evolution relevant to language’ (191–223), is the one that exactly fits the title of the volume, linking significantly to all three of its topics. This paper alone is worth the price of the whole volume. The theme he elaborates is that ‘The evolution of language obviously presupposes a brain that made language possible’ (191) and that ‘a critical force of the evolution of the human brain must have been language’ (191). We thus have ‘a coevolutionary process in which both language and brain evolved to suit each other’ (191). It follows that the evolution of language must have been a very long process occurring in...