In MOTHER TONGUE: HOW HUMANS CREATE LANGUAGE, Davis brings together information from the fields of biology, linguistics, psychology, and child development in order to consider the nature of human language, its creation by the human species, and its re-creation in individual members of the species.
The general reader is led from broad linguistic definitions of language to an overview of the human family of languages. Davis surveys the link between human anatomy and human speech as well as the ambiguous relationship between sound and meaning. He also traces the history of the sciences of linguistics from its origins in the time of Plato to the twentieth century theories of Noam Chomsky.
The central role of the human brain in speech development receives particular attention, as Davis describes various parts of the brain and the pioneering work of nineteenth and twentieth century scientists who have studied the consequences of brain trauma on human speech and memory. Davis suggests that the brain functions much like a computer HyperCard in its storage and retrieval of information.
Finally Davis moves from phylogeny to ontogeny and considers how the human child learns to speak. He follows the infant from its first meaningless babble to more coherent stages of language and the acquisition of refined linguistic forms like the English past tense suffix “-ed.” Deafness and bilingualism have their own effects on language development, which may or may not be replicated in the sounds of the animal world, especially among chimpanzees, or even, Davis hypothesizes, among extraterrestrial creatures.
MOTHER TONGUE is richly illustrated with diagrams of human anatomy and linguistic charts. Appendices include lists of the languages of the world and of the Indo-European language family, phonetic symbols, pronunciation guides for some linguistic symbols, and a chronology of the English language.