Situations of multilingualism and language contact in which language varieties are small in scale and relatively equal in social status are important phenomena affecting processes of language change throughout human history. Despite this, our knowledge about the outcomes of multilingualism and language contact in this kind of setting remains limited. The current thesis provides insight into the linguistic consequences of interaction between closely-related, recently-described, small-scale language varieties in the community and in the minds of bilinguals, and works to overcome some of the methodological challenges associated with the study of language contact and multilingualism in this type of setting. The studies of the thesis investigate...