Semantics

This article presents two experiments testing English children’s understanding of the “force” of modals, asking whether they understand that can expresses possibility and have_to expresses necessity. Prior studies show that children tend to over-accept necessity modals in possibility situations and argue this behavior stems from conceptual difficulties reasoning about open possibilities. However, these studies typically test modal force using epistemic modality (knowledge-based), which is less input-frequent than nonepistemic modalities (actual-world priorities or goals) and involves speaker perspective-taking. Our results with more familiar teleological (goal-oriented) modality show that preschoolers have an adult-like understanding of possibility can, but they seem to treat necessity have_to as a possibility modal, in affirmative (Experiment 1) and arguably in negative sentences (Experiment 2). We take these systematic errors to call into question conceptual accounts. We argue that younger preschoolers’ difficulties with modal force are due to word-learning challenges: They treat necessity modals as possibility modals.

Children use correlations between the syntax of a clause and the meaning of its predicate to draw inferences about word meanings. On one proposal, these inferences are underwritten by a structural similarity between syntactic and semantic representations: learners expect that the number of clause arguments exactly matches the number of participant roles in the event concept under which its referent is viewed. We argue against this proposal, and in favor of a theory rooted in syntactic and semantic contents – in mappings from syntactic positions to thematic relations. We (i) provide evidence that infants view certain scenes under a concept with three participant relations (a girl taking a truck from a boy), and (ii) show that toddlers do not expect these representations to align numerically with clauses used to describe those scenes: they readily accept two-argument descriptions (“she pimmed the truck!”). This argues against syntactic bootstrapping theories underwritten by mappings between structural features of syntactic and semantic representations. Instead, our findings support bootstrapping based on grammatical and thematic content. Children’s earliest inferences may rely on the assumption that the syntactic asymmetry between subject and object correlates with a difference in how their referents relate to the event described by the sentence.

Events of social exchange, such as givings and tradings, are uniquely prevalent in human societies and cognitively privileged even at early stages of development. Such events may be represented as having 3 or even 4 participants. To do so in visual working memory would be at the limit of the system, which throughout development can track only 3 to 4 items. Using a case study of trading, we ask (i) whether adults can track all four participants in a trading scene, and (ii) whether they do so by chunking the scene into two giving events, each with 3 participants, to avoid placing the visual working memory system at its limit. We find that adults represent this scene under a 4-participant concept, and do not view the trade as two sequential giving events. We discuss further implications for event perception and verb learning in development.