Language and Theory of Mind come together in communication, but their relationship has been intensely contested. I hypothesize that pragmatic markers connect language and Theory of Mind and enable their co-development and co-evolution through a positive feedback loop, whereby the development of one skill boosts the development of the other. I propose to test this hypothesis by investigating two types of pragmatic markers: demonstratives and articles. Pragmatic markers are closed-class words that encode non-representational information that is unavailable to consciousness, but (...) accessed automatically in processing. These markers have been associated with implicit Theory of Mind because they are used to establish joint attention and mark shared knowledge. Here I develop a theoretical account of how joint attention is the basis for children’s later tracking of common ground. The developmental path from joint attention to common ground parallels language change, with demonstrative forms giving rise to definite articles. This parallel opens the possibility of modelling the emergence of Theory of Mind in human development in tandem with its routinization across language communities and generations of speakers. I therefore propose that, in order to understand the relationship between language and Theory of Mind, we should study pragmatics at three parallel timescales: during language acquisition, language use, and language change. (shrink)

We evaluate the richness of the child’s input in semantics and its relation to the hypothesis space available to the child. Our case study is the acquisition of the universal quantifier every. We report two main findings regarding the acquisition of every on the basis of a corpus study of child-directed and child-ambient speech. Our first finding is that the input in semantics is rich enough to systematically eliminate instances of the subset problem of language acquisition: overly general hypotheses about (...) the meaning of every can violate pragmatic constraints, making such hypotheses incompatible with the child’s input. Our second finding is that the semantic input is too poor to eliminate instances of what we refer to as the superset problem, the mirror image of the subset problem. We argue that at least some overly specific hypotheses about the meaning of every are compatible with the child’s input, suggesting either that those hypotheses are not made available by UG or that non-trivial inductive biases are involved in children’s acquisition of every. (shrink)

Lidz also ponders the theory of syntactic bootstrapping by asking why it is that learners are considered to retain little of extralinguistic environments (i.e., their observations) during word learning, while being able to retain detailed representations of linguistic context, for example, the multiple syntactic frames in which a verb appears. Lidz argues that learners value syntactic information over extralinguistic context from the beginning of learning, consistent with syntactic bootstrapping as a key device for verb learning.

I argue that semantics is the study of the proprietary database of a centrally inaccessible and informationally encapsulated input–output system. This system’s role is to encode and decode partial and defeasible evidence of what speakers are saying. Since information about nonlinguistic context is therefore outside the purview of semantic processing, a sentence’s semantic value is not its content but a partial and defeasible constraint on what it can be used to say. I show how to translate this thesis into a (...) detailed compositional-semantic theory based on the influential framework of Heim and Kratzer. This approach situates semantics within an independently motivated account of human cognitive architecture and reveals the semantics–pragmatics interface to be grounded in the underlying interface between modular and central systems. (shrink)

A key factor that affects whether and at what age children can demonstrate an understanding of false belief and complement‐clause constructions is the type of task used (whether it is implicit/indirect or explicit/direct). In the current study, we investigate, in an implicit/indirect way, whether children understand that a story character's belief can be true or false, and whether this understanding affects children's choice of linguistic structure to describe the character's belief or to explain the character's belief‐based action. We also measured (...) children's understanding of false belief in explicit false‐belief tasks. English‐ and German‐speaking young 4‐ and 5‐year‐olds as well as English‐ and German‐speaking adult controls heard complement‐clause constructions in a story context where the belief mentioned in the complement clause (e.g., “He thinks thatshe's not feeling well”) turned out to be false, true, or was left open. After hearing the test question (“Why does he not play with her?”), all age groups were most likely to repeat the whole complement‐clause construction when the belief turned out to be false. That is, they tended to explicitly refer to the character's perspective and say “He thinks…” When the belief turned out to be true, participants often reverted to a simple clause (“She's not feeling well”). Furthermore, children with better short‐term memory were more likely to repeat the whole complement‐clause construction. However, children's performance in explicit false‐belief tasks showed no relation to their performance in our novel, more implicit/indirect, task. Whether or not the complement clause was introduced by athatcomplementizer only had a small effect on the German adults’ responses, where leaving out the complementizer also changes the word order of the complement clause. Overall, our results suggest that task characteristics and individual differences in short‐term memory affect children's ability to demonstrate false‐belief understanding and to express this understanding linguistically. (shrink)