Plurality inferences are scalar implicatures: evidence from acquisition

This paper provides novel experimental evidence for a scalar implicature approach to the plurality inferences that are associated with English plural morphology (Emily fed giraffes Emily fed more than one giraffe). Using a Truth Value Judgment Task, we show that both adults and 4–5-year-old children compute more plurality inferences in upward-entailing than downward-entailing environments, but children compute fewer plurality inferences overall than adults do. These findings are consistent with previous research demonstrating children’s relative insensitivity to scalar implicatures. We discuss the implications of these findings for theories of plurality inferences, and for the acquisition of scalar inferences more generally.