1.1.3 The intersection of linguistics with other disciplines

Language is used within all human communities, many of which have no regular written form for their language, or did not until the twentieth century. Although it is now fairly common for linguists to enter a pre-literate community and attempt to describe their language, for most of the twentieth century it was anthropologists who undertook fi eld work in such communities with the primary aim of describing their social structures and customs; to accomplish those goals most effectively, they needed to learn the people’s language. Field linguistics applies the methods of data elicitation and data collection in order to document, describe and analyse languages and language practices in their natural habitat – within the community of native speakers under investigation. The primary mission of anthropological linguistics is to tie forms of language to the social structures and customs of a people. There is a slight overlap here with the work of sociolinguists. A principal difference is that sociolinguistics focuses on the varieties of language used among different groups within a particular language community. Sociolinguists also investigate language change through time by plotting the spreading adoption of new forms and the decay of old ones, which is often accelerated during periods of social stress and change. Concepts of politeness and offensiveness differ among different social groups, and such social conventions and their correlation with social relations are also topics relevant to sociolinguistics.

Psycholinguistics draws from linguistics, psychology, cognitive science and the study of language pathology. Psycholinguists research cognitive and psychological aspects of the perception of categorical similarities and differences among phenomena. They investigate language production on the one hand and language processing and comprehension on the other. Developmental psycholinguistics examines first language acquisition and psycholinguists also study the acquisition of second languages. Knowing what is normal for human language use enables dysfunction to be recognized and potentially treated. Because linguistic dysfunction usually correlates with other mental dysfunction, language offers a path into (ab)normal cognitive behaviour. Whereas psycholinguistics focuses on the human mind, neurolinguistics focuses on the allied physiological matter of the human brain: the organ that enables the cognitive abilities we associate with the mind. Since the mid-nineteenth century it has been known that trauma to certain parts of the brain causes fairly predictable linguistic defi ciencies. Since the development of neural imaging techniques, knowledge of brain function has blossomed; as a result there has been progressive refi nement in mapping the functions of different areas of the brain which has revealed the great extent to which different areas of the brain operate together to, among other things, facilitate language use.