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

Emotions before actions: When children see costs as causal

Adults expect people to be biased by sunk costs, but young children do not. We tested between two accounts for why children overlook the sunk cost bias. On one account, children do not see sunk costs as causal. The other account posits that children see sunk costs as causal, but unlike adults, think future actions cannot make up for sunk costs. These accounts make opposing predictions about whether children should see sunk costs as affecting emotions. Across three experiments, 4-7-year-olds (total N = 320) and adults (total N = 429) saw stories about characters who collected items that were easy or difficult to obtain, and predicted characters' emotions and actions. At all ages, participants anticipated that characters would feel sadder about high-cost objects, but only adults predicted that characters would keep high-cost objects. Our findings show that children see incurred costs as causal, and that costs are integrated children's and adults' theory of emotions. Moreover, the findings suggest that developmental differences in sunk cost reasoning may rest in children's incomplete mental accounting. We also discuss children's reasoning about rational and irrational action.

Not just if, but how much: Children and adults use cost and need to make evaluations about generosity across contexts

Evaluations of others' generosity are critical for selecting quality social partners, yet the factors which systematically affect these evaluations and whether they vary across development are still relatively unclear. Here, we establish that two key dimensions adults and children (aged 4 to 7 years) consider are the cost associated with a giving action and the need of the recipient, through six pre-registered experiments with Canadian and U.S. American participants. Experiments 1 and 2 demonstrate that adults' and children's third-party evaluations of generosity are sensitive to variations in each factor, across several operationalizations of cost and need in both comparative and standalone contexts, suggesting cost and need can be spontaneously evoked. However, children's responses were more consistent for need scenarios than cost scenarios. In Experiments 3 and 4, we modified our scenarios to evaluate whether variations in cost and need are considered simultaneously in both generosity evaluations and affiliative preferences. Adults' and older children's (ages 6 to 7) evaluations of generosity and affiliative preferences were sensitive to both factors, but younger children did not utilize this information systematically. Importantly, in Experiments 5 and 6, adults' and older children's generosity evaluations were only sensitive to information about cost and need when the giver's actions conferred utility to a recipient, but not when actions were self-serving. Taken together, we establish robust evidence that cost and need are considered in generosity evaluations by demonstrating that Canadian and U.S. American adults and children utilize this information consistently, spontaneously, and simultaneously.

Not Playing by the Rules: Exploratory Play, Rational Action, and Efficient Search

Recent studies suggest children's exploratory play is consistent with formal accounts of rational learning. Here we focus on the tension between this view and a nearly ubiquitous feature of human play: In play, people subvert normal utility functions, incurring seemingly unnecessary costs to achieve arbitrary rewards. We show that four-and-five-year-old children not only infer playful behavior from observed violations of rational action (Experiment 1), but themselves take on unnecessary costs during both retrieval (Experiment 2) and search (Experiments 3A-B) tasks, despite acting efficiently in non-playful, instrumental contexts. We discuss the value of such apparently utility-violating behavior and why it might serve learning in the long run.

Having less means wanting more: Children hold an intuitive economic theory of diminishing marginal utility

Judgments surrounding resource acquisition and valuation are ubiquitous in daily life. How do humans decide what something is worth to themselves or someone else? One important cue to value is that of resource quantity. As described by economists, the principle of diminishing marginal utility (DMU) holds that as resource abundance increases, the value placed on each unit decreases; likewise, when resources become more scarce, the value placed on each unit rises. While prior research suggests that adults make judgments that align with this concept, it is unclear whether children do so. In Study 1 (n = 104), children (ages 5 through 8) were presented with scenarios involving losses or gains to others' resources and predicted the actions and emotions of the individuals involved. Participants made decisions that aligned with DMU, e.g., expecting individuals with fewer resources to expend more effort for an additional resource than individuals with greater resources. In Study 2 (n = 104), children incorporated information about preferences when inferring others' resource valuations, showing how quantity and preference are both included in children's inferences about others' utility. Our results indicate the early emergence of an intuitive economic theory that aligns with an important economic principle. Long before formal learning on this topic, children integrate quantity and preference information to sensibly predict others' resource valuations, with implications for economic decision-making, social preferences, and judgments of partner quality across the lifespan.

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.

What Could Go Wrong: Adults and Children Calibrate Predictions and Explanations of Others' Actions Based on Relative Reward and Danger

When human adults make decisions (e.g., wearing a seat belt), we often consider the negative consequences that would ensue if our actions were to fail, even if we have never experienced such a failure. Do the same considerations guide our understanding of other people's decisions? In this paper, we investigated whether adults, who have many years of experience making such decisions, and 6- and 7-year-old children, who have less experience and are demonstrably worse at judging the consequences of their own actions, conceive others' actions as motivated both by reward (how good reaching one's intended goal would be), and by what we call "danger" (how badly one's action could end). In two pre-registered experiments, we tested whether adults and 6- and 7-year-old children tailor their predictions and explanations of an agent's action choices to the specific degree of danger and reward entailed by each action. Across four different tasks, we found that children and adults expected others to negatively appraise dangerous situations and minimize the danger of their actions. Children's and adults' judgments varied systematically in accord with both the degree of danger the agent faced and the value the agent placed on the goal state it aimed to achieve. However, children did not calibrate their inferences about how much an agent valued the goal state of a successful action in accord with the degree of danger the action entailed, and adults calibrated these inferences more weakly than inferences concerning the agent's future action choices. These results suggest that from childhood, people use a degree of danger and reward to make quantitative, fine-grained explanations and predictions about other people's behavior, consistent with computational models on theory of mind that contain continuous representations of other agents' action plans.

Time pressure changes how people explore and respond to uncertainty

How does time pressure influence exploration and decision-making? We investigated this question with several four-armed bandit tasks manipulating (within subjects) expected reward, uncertainty, and time pressure (limited vs. unlimited). With limited time, people have less opportunity to perform costly computations, thus shifting the cost-benefit balance of different exploration strategies. Through behavioral, reinforcement learning (RL), reaction time (RT), and evidence accumulation analyses, we show that time pressure changes how people explore and respond to uncertainty. Specifically, participants reduced their uncertainty-directed exploration under time pressure, were less value-directed, and repeated choices more often. Since our analyses relate uncertainty to slower responses and dampened evidence accumulation (i.e., drift rates), this demonstrates a resource-rational shift towards simpler, lower-cost strategies under time pressure. These results shed light on how people adapt their exploration and decision-making strategies to externally imposed cognitive constraints.