The connection between language and identity is a fundamental element of our experience of being human. Language not only reflects who we are but in some sense it is who we are, and its use defines us both directly and indirectly. We use language in a direct way to denote and describe who a person is through use of naming and kinship terms, descriptions based on appearance, behaviour, background, and so on, and we use language to assign identities indirectly when we base our judgements of who people are on the way they speak. Language-mediated attribution of identity to individuals is so ingrained in human social affairs that we consider a person lacking a name to also lack an identity.
Neither our identities nor our language are static, however. Both are constantly shifting and being re-negotiated in response to the ever-changing contexts of our interactions. Yet for both our identity and our language there are elements which remain essences. Our DNA, our fingerprints, our unique facial characteristics and body markings remain constant, rare exceptions apart, and form the basis of our individual identities. Like fingerprints, human vocal tracts are to the best of our knowledge anatomically unique to each individual. The combination of features they produce in spoken language allows listeners to recognise a sample of speech as belonging to a particular talker, and prevents others from reproducing his or her speech patterns precisely. These fundamentals can be seen as marking us out as unique individuals. But in addition to personal identity, we are also social beings with social identities. The variations in our dress, appearance and behaviour, and the constant variability in our language use, mark us out as belonging to social groups. We can be members of a potentially infinite number of intersecting social groups, be they local (friends, family, colleagues, and so forth) or global (gender, class, ethnicity, nationality), whose membership is reflected in our shared linguistic behaviour. Any interaction we experience can be characterised and perceived along both intergroup and interindividual dimensions, a duality which accounts for some of the extraordinary complexity of language use. All sociolinguistically competent language users can draw upon an array of linguistic resources for foregrounding different aspects of their identities in particular contexts at particular times. Through the following chapters by leading researchers in the field, this volume investigates the connections and correlations between different levels of our linguistic behaviour and diverse facets of our identities.