Parallel developmental changes in children's production and recognition of line drawings of visual concepts.

Childhood is marked by the rapid accumulation of knowledge and the prolific production of drawings. We conducted a systematic study of how children create and recognize line drawings of visual concepts. We recruited 2-10-year-olds to draw 48 categories via a kiosk at a children's museum, resulting in >37K drawings.

Visual explanations prioritize functional properties at the expense of visual fidelity.

Visual explanations play an integral role in communicating mechanistic knowledge about how things work. What do people think distinguishes such pictures from those that are intended to convey how things look? To explore this question, we used a drawing paradigm to elicit both visual explanations and depictions of novel machine-like objects, then conducted a detailed analysis of the semantic information conveyed in each drawing. We found that visual explanations placed greater emphasis on parts of the machines that move or interact to produce an effect, while visual depictions emphasized parts that were visually salient, even if they were static.

Mind-bending geometry: Children's and adults' intuitions about linearity on spheres.

Humans appear to intuitively grasp definitions foundational to formal geometry, like definitions that describe points as infinitely small and lines as infinitely long. Nevertheless, previous studies exploring human's intuitive natural geometry have consistently focused on geometric principles in planar Euclidean contexts and thus may not comprehensively characterize humans' capacity for geometric reasoning. The present study explores whether children and adults can reason about linearity in spherical contexts.

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.

Social Pragmatics: Preschoolers Rely on Commonsense Psychology to Resolve Referential Underspecification.

Four experiments show that 4- and 5-year-olds (total N = 112) can identify the referent of underdetermined utterances through their Naïve Utility Calculus-an intuitive theory of people's behavior structured around an assumption that agents maximize utilities. In Experiments 1-2, a puppet asked for help without specifying to whom she was talking ("Can you help me?"). In Experiments 3-4, a puppet asked the child to pass an object without specifying what she wanted ("Can you pass me that one?").