The development of lexical biases in grammatical variation. Exemplar-driven and index-driven lectal contamination.

Mechanisms of language variation and change often take as starting point lexical biases in grammatical variation, i.e. the finding that particular words engender speakers to prefer one construction over another while forming utterances. For example, a frequent word that is biased towards a construction may attract similar words through analogy, creating a new conjugation class. What is unclear, however, is how such lexical biases develop in the first place.
To understand this, the project introduces two mechanisms that can create such lexical biases, viz. exemplar-driven and index-driven lectal contamination. Both mechanisms start from language contact between two varieties of the same language, but differ in how such contact leads to lexical biases within the varieties. Exemplar-driven contamination relies on the cognitive storage of exemplars, while index-driven contamination assumes that the words and constructions act as social indices.
A pilot study focusing on nominal morphological variation has already been completed, with positive results. The project will conduct four more corpus-based case studies that test the effect of both mechanisms among other types of variation. Next, I will build an agent-based simulation of each mechanism. This will allow me to validate both mechanisms in-silico and derive exact theoretical predictions for each mechanism. Finally, these predictions will be put to the test through corpus research and a forced-choice and receptive experiment.