Book excerpt: The Onset of Language outlines an approach to the development of expressive and communicative behaviour from early infancy to the onset of single word utterances. Nobuo Masataka's research is rooted in ethology and dynamic action theory. He argues that expressive and communicative actions are organized as a complex and cooperative system with other elements of the infant's physiology, behaviour and the social environments. Overall, humans are provided with a finite set of specific behaviour patterns, each of which is phylogenetically inherited as a primate species. However, the patterns are uniquely organized during ontogeny and a coordinated structure emerges which eventually leads us to acquire language. This fascinating book offers exciting insights into the precursors of speech and will be of interest to researchers and students of psychology, linguistics and animal behaviour biology.