Sources of developmental change in pragmatic inferences about scalar terms

Pragmatic implicatures—inferences that weak statements imply that stronger ones could not be used—are a popular case study of children’s pragmatic development. A growing literature suggests that children make implicatures under certain conditions, but their performance varies widely across tasks, and few datasets allow direct comparisons between implicature types. We designed a simple paradigm to address these issues. In Experiment 1, we included both ad-hoc (contextual) and scalar (quantifier) descriptions and found that 4-year-olds were at ceiling in ad-hoc trials but had difficulty with scalar implicatures. In Experiment 2, 4-year-olds’ performance increased when we included only scalar trials, but was still low. Across both datasets, performance for “some” and “none” quantifiers was positively correlated. Our work provides more precise developmental data on the emergence of different implicature computations and illustrates that preschoolers’ recognition of implicatures relates both to their comprehension of particular lexical items and also their recognition of relevant alternatives.