Reviewed by Julie B. Lake, Georgetown University
and Sonja A. Kotz, Max Planck Institute for Human Cognitive and Brain Sciences, Germany
Toward an evolutionary biology of language is an impressive book that synthesizes an enormous amount of information. Lieberman addresses ‘the nature and evolution of the biologic bases of human language’ (1), drawing on a wide array of information from human and animal studies, including linguistic, neuronal, anatomical, and philological. The book is structured to be accessible to novices or experts, as it straddles two areas of research that are integrally linked without successful communication between their practitioners, linguistics and neuroscience.
Each topic is introduced with a toolbox, giving the ‘nuts and bolts’ terms needed to understand the following chapter and describing important aspects and assumptions of the area. Each of the eight chapters ends with a series of ‘take-home messages’ that order and highlight information. The book weaves together many themes, but L’s main goal is to counter a location-based model of brain functioning, emphasizing instead the role of the neural networks of the basal ganglia and other structures.
How language works is quite complex; this book offers the first steps toward a falsifiable evolutionary biology of language. L describes the ‘primitive’ and ‘derived’ features of human language through a review of comparative studies with present-day apes (Ch. 2); begins to tease apart exactly how speech is ‘singular’ (Ch. 3); identifies biological, cognitive, and perceptual elements of speech (Ch. 4); covers the role of different neural correlates in language and details how ‘the evolution of the neural mechanisms initially adapted for motor control appears to be the key to the evolutionary process that yields our ability to create a potentially infinite number of actions or thought processes from a finite number of stereotyped motor sequences, words, or thoughts’ (12, describing Ch. 5); looks at the anatomical aspects of speech (Ch. 6); and attempts to integrate the findings of neuroscience and evolutionary biology into linguistic research (Ch. 7). Ch. 8 suggests future directions for research towards a more falsifiable evolutionary biology of language.
In summary, L proposes that the Broca-Wernicke language organ theory current among theoretical linguists is incorrect, as subcortical structures such as the basal ganglia have been implicated in language as well as motor control and creative/flexible intelligence. He further discusses possible neural networks underlying language processing, and argues that the neural structures used in speech production, in both its voluntary aspects and the syntactic ability to produce unlimited words and sentences, have been adapted from those involved in motor control (e.g. walking).
Overall this is an impressive, challenging, and commendable book on the neuroscience of language. For linguists in general L offers a fair but well-needed critique of theoretical linguistic claims about ‘the way language works’. Furthermore, many sections of the book offer comprehensive overviews of linguistic topics (e.g. articulatory phonetics/phonology) that should be helpful to a novice. Some sections are more philosophical (e.g. reflections on cognitive flexibility and reiterative syntactic mechanisms) and invite the interested reader to think further about the evolutionary biology of language.