Shared syntax between comprehension and production: Multi-paradigm evidence that resumptive pronouns hinder comprehension.

Language comprehension and production are generally assumed to use the same representations, but resumption poses a problem for this view: This structure is regularly produced, but judged highly unacceptable. Production-based solutions to this paradox explain resumption in terms of processing pressures, whereas the Facilitation Hypothesis suggests resumption is produced to help listeners comprehend. Previous research purported to support the Facilitation Hypothesis did not test its keystone prediction: that resumption improves accuracy of interpretation. Here, we test this prediction directly, controlling for factors that previous work did not. Results show that resumption in fact hinders comprehension in the same sentences that native speakers produced, a finding which replicated across four high-powered experiments with varying paradigms: sentence-picture matching (N=300), self-paced reading (N=96), visual world eye-tracking (N=96), and multiple-choice comprehension question (N=150). These findings are consistent with production-based accounts, indicating that comprehension and production may indeed share representations, although our findings point toward a limit on the degree of overlap. Methodologically speaking, the findings highlight the importance of measuring interpretation when studying comprehension.