The Trouble With Quantifiers: Exploring Children's Deficits in Scalar Implicature.

Adults routinely use the context of utterances to infer a meaning beyond the literal semantics of their words (e.g., inferring from "She ate some of the cookies" that she ate some, but not all). Contrasting children's (N = 209) comprehension of scalar implicatures using quantifiers with contextually derived ad hoc implicatures revealed that 4- to 5-year-olds reliably computed ad hoc, but not scalar, implicatures (Experiment 1). Unexpectedly, performance with "some" and "none" was correlated (Experiments 1 and 2). An individual differences study revealed a correlation between quantifier knowledge and implicature success (Experiment 3); a control study ruled out other factors (Experiment 4). These findings suggest that some failures with scalar implicatures may be rooted in a lack of semantic knowledge rather than general pragmatic or processing demands.