People tell stories to impose coherence on the continuous stream of everyday experience. But there are countless ways of narrativizing the same situation. How do we decide which features to gloss over, which features to elaborate on, and what order to recount them in? Here, we explore the hypothesis that people systematically adapt narratives with respect to their communicative goals. In one experiment (N=273), participants watched Heider-Simmel style animations and were asked to tell a story about what is happening in each video. They were randomly assigned to one of three goals: to tell a generic story, to chronicle the events like a reporter, or to share a juicy piece of gossip. We present a series of exploratory natural language analyses examining how these goals shape stories. Chronicles are more detailed relative to gossip, but gossip references more high-level social features. These findings underscore how Gricean principles of relevance drive storytelling.

Context-sensitive communication not only requires speakers to choose relevant utterances from alternatives, but also to retrieve and evaluate the relevant utterances from memory in the first place. In this work, we compared different proposals about how underlying semantic representations work together with higher-level selection processes to enable individuals to flexibly utilize context to guide their language use. We examined speaker and guesser performance in a two-player iterative language game based on Codenames, which asks speakers to choose a single `clue' word that allows their partner to select a pair of target words from a context of distractors. The descriptive analyses indicated that speakers were sensitive to the shared semantic neighborhood of the target word pair and were able to use guesser feedback to shift their clues closer to the unguessed word. We also formulated a series of computational models combining different semantic representations with different selection processes. Model comparisons suggested that a model which integrated contextualized lexical representations based on association networks with a contextualized model of pragmatic reasoning was better able to predict behavior in the game compared to models that lacked context at either the representational or process level. Our findings suggest that flexibility in communication is driven by context-sensitivity at at the level of both representations and processes.

Toddlers are sensitive to the reliability of speakers in their environment \cite{koenig2010}. While previous work suggests that children prefer labels from reliable speakers, it remains unclear how these social representations guide lower-level information-seeking processes that affect speaker preferences. The current study introduces a gaze-contingent eye-tracking paradigm to investigate how children engage in sampling during word learning. Toddlers (22-24m) view videos of two speakers labeling familiar objects; one speaker provides reliable labels and the other speaker provides unreliable labels. Toddlers then sample novel labels from the speakers using a gaze-contingent interface: only the speaker they are fixating on provides a novel label. Preliminary data (N = 18) suggests that participants prefer to sample first from the reliable speaker over the unreliable speaker. However, there is little difference in overall sampling preferences. Our findings suggest that toddlers can assess speaker reliability, but remain open to exploring information from unreliable speakers.

Adults readily form pacts, or temporary agreements about ref-erent names, over the course of conversation. Young childrenfail to do so with peers, but recent evidence suggests that ex-plicit feedback from adults may improve their performance(Matthews, Lieven, & Tomasello, 2007). Do parents natu-rally provide such structure in their conversations with chil-dren? Using a director-matcher paradigm, we first show thatparents and children (ages 4, 6, 8) converge on increasinglyaccurate and efficient conversational pacts. Further, parents ofyounger children provide more interactive feedback. Finally,we analyze asymmetries in parents’ and children’s contribu-tions, finding that pacts tend to originate with the parent, butare simplified by younger children. Together, these resultssupport the idea that parents sensitively adapt their languageto their children’s developmental level to scaffold successfulcommunication.

Theory of mind is a powerful cognitive ability: by the ageof six, people are capable of accurately reasoning about oth-ers’ beliefs and desires. An influential series of language un-derstanding experiments by Keysar and colleagues, however,showed that adults systematically failed to take a speaker’sbeliefs into account, revealing limitations on theory of mind.In this paper we argue that these apparent failures are in factsuccesses. Through a minimal pair of replications comparingscripted vs. unscripted speakers, we show that critical utter-ances used by Keysar and colleagues are uncooperative: theyare less informative than what a speaker would actually pro-duce in that situation. When we allow participants to naturallyinteract, we find that listener expectations are justified and er-rors are reduced. This ironically shows that apparent failuresof theory of mind are in fact attributable to sophisticated ex-pectations about speaker behavior—that is, to theory of mind.

Children rapidly learn to use language to effect a variety of communicative acts, such as proposing actions, asking questions, and making promises. While prior work has characterized this development in cross-sectional corpora, these analyses have been unable to comprehensively track individual differences in children's acquisition of communicative acts. We analyzed a longitudinal corpus of parent-child interactions from ages 14 to 58 months. We find that children's repertoires of communicative acts diversify over this period, with stable individual differences in the diversity of children's communicative act repertoires. Further, the diversities of parents' and children's communicative act repertoires are correlated. Children with more diverse communicative act repertoires also have larger vocabularies and use more diverse syntactic frames, suggesting links between discourse development and lexical and syntactic knowledge. Taken together, this work provides new insight into individual trajectories of communicative development and connections between communicative act use and other levels of language structure.

When faced with a polar question, speakers often provide overinformative answers going beyond a simple “yes” or “no”. But what principles guide the selection of additional information? In this paper, we provide experimental evidence from two studies suggesting that overinformativeness in human answering is driven by considerations of relevance to the questioner’s goals which they flexibly adjust given the functional context in which the question is uttered. We take these human results as a strong benchmark for investigating question-answering performance in state-of-the-art neural language models, conducting an extensive evaluation on items from human experiments. We find that most models fail to adjust their answering behavior in a human-like way and tend to include irrelevant information. We show that GPT-3 is highly sensitive to the form of the prompt and only achieves human-like answer patterns when guided by an example and cognitively-motivated explanation.

Inspired by inductive reasoning models, we test whether generalized shared reality (i.e., the sense of being on the same page) arises through probabilistic inference about latent commonalities. Using a naturalistic text-based chat paradigm, we manipulated whether conversation partners discussed a belief they shared, a belief on which their opinions differed, or a random prompt. Participants discussing shared opinions reported experiencing greater shared reality compared to those discussing differences or random topics. Moreover, participants who made broader inferences about additional beliefs they might share with their partners also reported greater shared reality. While discussing shared opinions can induce an overall greater sense of shared reality, participants discussing differences leveraged their conversation to establish shared realities about other topics. We demonstrate that shared reality can emerge in multiple ways during initial interactions, establishing a foundation for future mechanistic investigations within an inductive inference framework.

Speakers communicate to influence their partner's beliefs and shape their actions. Belief- and action-based objectives have been explored independently in recent computational models, but it has been challenging to explicitly compare or integrate them. Indeed, we find that they are conflated in standard referential communication tasks. To distinguish these accounts, we introduce a new paradigm called signaling bandits, generalizing classic Lewis signaling games to a multi-armed bandit setting where all targets in the context have some relative value. We develop three speaker models: a belief-oriented speaker with a purely informative objective; an action-oriented speaker with an instrumental objective; and a combined speaker which integrates the two by inducing listener beliefs that generally lead to desirable actions. We then present a series of simulations demonstrating that grounding production choices in future listener actions results in relevance effects and flexible uses of nonliteral language. More broadly, our findings suggest that language games based on richer decision problems are a promising avenue for insight into rational communication.

A long tradition of studies in psycholinguistics has examined the formation and generalization of ad hoc conventions in reference games, showing how newly acquired conventions for a given target transfer to new referential contexts. However, another axis of generalization remains understudied: how do conventions formed for one target transfer to completely distinct targets, when specific lexical choices are unlikely to repeat? This paper presents two dyadic studies (N=240) that address this axis of generalization, focusing on the role of nameability --- the a priori likelihood that two individuals will share the same label. We leverage the recently-released KiloGram dataset, a collection of abstract tangram images that is orders of magnitude larger than previously available, exhibiting high diversity of properties like nameability. Our first study asks how nameability shapes convention formation, while the second asks how new conventions generalize to entirely new targets of reference. Our results raise new questions about how ad hoc conventions extend beyond target-specific re-use of specific lexical choices.