When Naïve Pedagogy Breaks Down: Adults Rationally Decide How to Teach, but Misrepresent Learners' Beliefs.

From early in childhood, humans exhibit sophisticated intuitions about how to share knowledge efficiently in simple controlled studies. Yet, untrained adults often fail to teach effectively in real-world situations. Here, we explored what causes adults to struggle in informal pedagogical exchanges. In Experiment 1, we first showed evidence of this effect, finding that adult participants failed to communicate their knowledge to naïve learners in a simple teaching task, despite reporting high confidence that they taught effectively. Using a computational model of rational teaching, we found that adults assigned to our teaching condition provided highly informative examples but failed to teach effectively because their examples were tailored to learners who were only considering a small set of possible explanations. In Experiment 2, we then found experimental evidence for this possibility, showing that knowledgeable participants systematically misunderstand the beliefs of naïve participants. Specifically, knowledgeable participants assumed naïve agents would primarily consider hypotheses close to the correct one. Finally, in Experiment 3, we aligned learners' beliefs to knowledgeable agents' expectations and showed learners the same examples selected by participants assigned to teach in Experiment 1. We found that these same examples were significantly more informative once learners' hypothesis spaces were constrained to match teachers' expectations. Our findings show that, in informal settings, adult pedagogical failures result from an inaccurate representation of what naïve learners believe is plausible and not an inability to select informative data in a rational way.

People infer communicative action through an expectation for efficient communication.

Humans often communicate using body movements like winks, waves, and nods. However, it is unclear how we identify when someone's physical actions are communicative. Given people's propensity to interpret each other's behavior as aimed to produce changes in the world, we hypothesize that people expect communicative actions to efficiently reveal that they lack an external goal. Using computational models of goal inference, we predict that movements that are unlikely to be produced when acting towards the world and, in particular, repetitive ought to be seen as communicative. We find support for our account across a variety of paradigms, including graded acceptability tasks, forced-choice tasks, indirect prompts, and open-ended explanation tasks, in both market-integrated and non-market-integrated communities. Our work shows that the recognition of communicative action is grounded in an inferential process that stems from fundamental computations shared across different forms of action interpretation.

Preschoolers decide who is knowledgeable, who to inform, and who to trust via a causal understanding of how knowledge relates to action.

Preschoolers are discerning learners, preferring to trust people who are accurate, reliable, and appropriately-informed. Do these preferences reflect mental-state reasoning, where children infer what others know from their behavior, or do they reflect a reliance on simple cues? In Experiment 1 we show that four- and five-year-olds can infer knowledge from others' behavior when superficial cues and actions are matched across agents. Experiments 2a and 2b further suggest that children track how agents acquired their knowledge, and may use this to determine what different agents will (and will not) know. Finally, Experiment 3 shows that children independently make these knowledge inferences when deciding whom to trust. Our findings suggest that by age four, children have expectations about how knowledge relates to action, use these expectations to infer what others know from what they do, and rely on these inferences when deciding whom to trust.

Not just what you did, but how: Children see distributors that count as more fair than distributors who don't.

To distribute resources in a fair way, identifying an appropriate outcome is not enough: We must also find a way to produce it. To solve this problem, young children spontaneously use number words and counting in fairness tasks. We hypothesized that children are also sensitive to other people's use of counting, as it reveals that the distributor was motivated to produce the outcome they believed was fair. Across four experiments, we show that U.S. children (N = 184 from the New Haven area; ages four to six; Approximately 58% White, 16% Black, 18% Hispanic, 4% Asian, and 4% other) believe that agents who count when distributing resources are more fair than agents who produce the same outcome without counting, even when both agents invest the same amount of effort. And vice versa, when the same two agents produce an unfair outcome, children now condemn the agent who counted. Our findings suggest that, from childhood, people understand that counting reflects a motivation to be precise and use this to evaluate other people's behavior in fairness contexts.

Says who? Children consider informants' sources when deciding whom to believe.

To successfully navigate the world, we cannot simply accept everything we hear as true. We must think critically about others' testimony, believing only sources who are well-informed and trustworthy. This ability is especially crucial in early childhood, a time when we both learn the most, and have the least prior knowledge we can fall back upon to verify others' claims. While even young children evaluate testimony by considering whether agents' firsthand experiences license their claims, much of the time, our informants do not possess firsthand knowledge. When agents transmit information learned from others (rather than discovered firsthand), can children also evaluate their testimony's social basis? Across 3 experiments (N = 390), we manipulate the number of primary sources originating a claim, and the number of secondary sources repeating it. We find that by age 6, children understand that a claim is only as reliable as its original source, endorsing claims supported by more primary (rather than secondary) sources. While young preschoolers already understand the link between firsthand perceptual access and knowledge, these results suggest that a full understanding of testimony's social basis may be later-developing. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

In Pursuit of Knowledge: Preschoolers Expect Agents to Weigh Information Gain and Information Cost When Deciding Whether to Explore.

When deciding whether to explore, agents must consider both their need for information and its cost. Do children recognize that exploration reflects a trade-off between action costs and expected information gain, inferring epistemic states accordingly? In two experiments, 4- and 5-year-olds (N = 144; of diverse race and ethnicity) judge that an agent who refuses to obtain low-cost information must have already known it, and an agent who incurs a greater cost to gain information must have a greater epistemic desire. Two control studies suggest that these findings cannot be explained by low-level associations between competence and knowledge. Our results suggest that preschoolers' theory of mind includes expectations about how costs interact with epistemic desires and states to produce exploratory action.

The Illusion of Consensus: A Failure to Distinguish Between True and False Consensus.

When evaluating information, we cannot always rely on what has been presented as truth: Different sources might disagree with each other, and sometimes there may be no underlying truth. Accordingly, we must use other cues to evaluate information-perhaps the most salient of which is consensus. But what counts as consensus? Do we attend only to surface-level indications of consensus, or do we also probe deeper and consider why sources agree? Four experiments demonstrated that individuals evaluate consensus only superficially: Participants were equally confident in conclusions drawn from a true consensus (derived from independent primary sources) and a false consensus (derived from only one primary source). This phenomenon was robust, occurring even immediately after participants explicitly stated that a true consensus was more believable than a false consensus. This illusion of consensus reveals a powerful means by which misinformation may spread.

Changes in cognitive flexibility and hypothesis search across human life history from childhood to adolescence to adulthood.

How was the evolution of our unique biological life history related to distinctive human developments in cognition and culture? We suggest that the extended human childhood and adolescence allows a balance between exploration and exploitation, between wider and narrower hypothesis search, and between innovation and imitation in cultural learning. In particular, different developmental periods may be associated with different learning strategies. This relation between biology and culture was probably coevolutionary and bidirectional: life-history changes allowed changes in learning, which in turn both allowed and rewarded extended life histories. In two studies, we test how easily people learn an unusual physical or social causal relation from a pattern of evidence. We track the development of this ability from early childhood through adolescence and adulthood. In the physical domain, preschoolers, counterintuitively, perform better than school-aged children, who in turn perform better than adolescents and adults. As they grow older learners are less flexible: they are less likely to adopt an initially unfamiliar hypothesis that is consistent with new evidence. Instead, learners prefer a familiar hypothesis that is less consistent with the evidence. In the social domain, both preschoolers and adolescents are actually the most flexible learners, adopting an unusual hypothesis more easily than either 6-y-olds or adults. There may be important developmental transitions in flexibility at the entry into middle childhood and in adolescence, which differ across domains.