Linguists usually discuss language or dialects in terms of groups of speakers. Believing that patterns can be seen more clearly in the group than the individual, researchers often present group scores with no indication of the variation within the group. Even though they all acknowledge that no two individuals speak alike, few study individual variation and voice. The individual has always been thought to be outside the purview of linguistic theory.

Johnstone makes the case for the importance of the role of the individual, and the individual's idiosyncrasies, in language and linguistics. Using theoretical arguments and discourse analysis, along with linguistic examples from a wide variety of speakers and settings, Johnstone illustrates how speakers draw on linguistic models associated with class, ethnicity, gender, region, among others, to construct individual ways of sounding. In doing so,she shows that certain important questions in sociolinguistics and pragmatics can only be fully answered with reference to individual speakers. Her study is important not only for the understanding of speech as expressive of self,but for the study of of variation and the mechanisms of linguistic choice and change.