Speakers use more redundant references with language learners: Evidence for communicatively-efficient referential choice

According to the communicative efficiency hypothesis, speakers should produce more linguistic material when comprehension difficulty increases. Here, we investigate a potential source of comprehension difficulty - listeners' language proficiency - on speakers' productions, using referential choice as a case study. Referential choice is influenced by communicative efficiency: pronouns are used less than full noun phrases (NPs) for less predictable referents (Tily & Piantadosi, 2009). However, the extent to which it is influenced by the listener is debated. Here, we compare participants' descriptions of the same picture book to children, adult L2 learners and adult native speakers. We find that speakers use more full NPs when their interlocutors are learners - child and adult learners alike, illustrating an effect of listeners' proficiency (regardless of age) on production choices. Importantly, the increased use of full NPs relative to pronouns is found controlling for discourse-related differences (e.g., previous mention), suggesting a direct relation between listeners' perceived language proficiency and referential choice.