Yarrow Dunham’s research while affiliated with Yale University and other places

Inferences about other people's knowledge and beliefs are central to social interaction. However, it is often not possible to tell what exactly other people know, because their behavior is consistent with a range of potential epistemic states. Nonetheless, in many of these situations we often have coarse intuitions about how much someone knows, despite being unable to pinpoint the exact content of their knowledge. Here we sought to explore this capacity in humans, by comparing their performance to a normative model capturing this kind of broad epistemic-state inference, centered on the expectation that agents maximize epistemic utilities. We evaluate our model in a graded inference task where people had to infer how much an agent knew based on the actions they chose (Experiment 1), and joint inferences about how much someone knew and how much they believed they could learn (Experiment 2). Critically, the agent's knowledge was always under-determined by their behavior, but the behavior nonetheless contained information about how much knowledge they possessed or believed they could gain. Our model captures nuanced patterns in participant judgments, revealing that people have a quantitative capacity to infer amorphous knowledge from minimal behavioral evidence.

Biases in favor of culturally prevalent social ingroups are ubiquitous, but random assignment to arbitrary experimentally created social groups is also sufficient to create ingroup biases (i.e., the minimal group effect; MGE). The extent to which ingroup bias arises from specific social contexts versus more general psychological tendencies remains unclear. This registered report focuses on three questions. First, how culturally prevalent is the MGE? Second, how do critical cultural and individual factors moderate its strength? Third, does the MGE meaningfully relate to culturally salient real-world ingroup biases? We compare the MGE to bias in favor of a family member (first cousin) and a national ingroup member. We propose to recruit a sample of > 200 participants in each of > 50 nations to examine these questions and advance our understanding of the psychological foundations and cultural prevalence of ingroup bias.

The ability to predict and understand other people’s actions is critical for real-world social behavior. Here we hypothesized that representations of social roles (e.g., cashier, mechanic, doctor) enable people to build rapid expectations about what others know and how they might act. Using a self-paced read- ing paradigm, we show that role representations support real time expectations about how other people might act (Study 1) and the knowledge they might possess (Study 2). Moreover, people reported more surprisal when the events deviated from role expectations, and they were more likely to misremember what happened. Our results suggest that roles are a powerful route for social understanding that has been previously under- studied in social cognition.

Human success in constructing and navigating a complex social world is typically associated with the ability to interpret other people’s behavior in terms of mental states—a mentalistic stance. We argue that humans are endowed with a second equally powerful intuitive theory: an institutional stance that interprets social interactions in terms of structured institutional representations. In contrast to the mentalistic stance, which helps us predict and understand unconstrained behavior via unobserved mental states, the institutional stance shapes and regulates behavior via normative expectations embedded in roles (i.e., institutions). Precursors of the institutional stance may also help explain non-human social behavior, supporting social interaction between conspecifics that lack complex models of each others’ mental states. At the same time, the institutional stance is unique in humans in its generative capacity, supporting rapid construction, tracking, and inference of institutional structures that shape our social world and enable the possibility of large scale social coordination and new forms of institutional life. Uniquely-human social cognition is best understood as an interplay between mentalistic mechanisms for predicting others’ behavior embedded in normative institutional structures that help render behavior predictable.

Despite increasing advocacy for gender equality, gender prejudice and discrimination persist. The origins of these biases develop in early childhood, but it is less clear whether (1) children's gender attitudes predict discrimination and (2) gender attitudes and discrimination vary by ethnicity and US region. We examine these questions with an ethnically (Asian, Black, Latinx and White) and geographically (Northeast, Pacific Northwest, West, Southeast and Hawaii) diverse sample of 4‐ to 6‐year‐old children ( N = 605) who completed measures of gender attitudes and discrimination in a preregistered study. Children, across groups, demonstrated more positive attitudes towards their gender ingroup. Children who showed more pro‐ingroup attitudes also showed more pro‐ingroup behavioural discrimination. Girls showed stronger ingroup favouritism than boys, but ethnic and regional groups generally did not vary in levels of bias. These findings contribute to our understanding of how gender intergroup biases develop and highlight the generalizability of these processes.

Throughout evolution, human cooperation has not only depended on individuals conforming to majority behaviors but has also relied on unique contributions from individuals. Extensive evidence has shown that even young children conform to majority preferences and evaluate non-conformists negatively. But to what extent do children also appreciate individuality in the form of unique skills? We examined this question across four preregistered studies with 6-9-year-old children from US and China ( N = 335). We found that children from the two cultures chose partners with unique skills in collaborative contexts (Studies 1–3) and actively sought to develop unique skills themselves (Study 4). Notably, children selectively valued uniqueness in skills but not personal preferences (Studies 1 and 4). These findings suggest that children appreciate unique attributes in themselves and others even when they come at the expense of conformity, shedding light on an essential psychological mechanism for promoting successful cooperation and innovation.

Across two preregistered studies with children (3–12-year-olds; N = 356) and adults (N = 262) from the United States, we find robust expectations for intergroup empathic biases. Participants predicted that people would feel better about ingroup fortunes than outgroup fortunes and worse about ingroup misfortunes than outgroup misfortunes. Expectations of empathic bias were stronger when there was animosity and weaker when there was fondness between groups. The largest developmental differences emerged in participants’ expectations about how others feel about outgroup misfortunes, particularly when there was intergroup animosity. Whereas young children (3–5-year-olds) generally expected people to feel empathy for the outgroup (regardless of the relationship between the groups), older children (9–12-year-olds) and adults expected Schadenfreude (feeling good when an outgroup experiences a misfortune) when the groups disliked one another. Overall, expectations of empathic biases emerge early but may be weaker when there are positive intergroup relationships.

Previous work has shown the robust nature of gender bias in both children and adults. However, much less attention has been paid toward understanding what factors shape these biases. The current preregistered study used parent surveys and child interviews to test whether parents’ conversations with their children about and modeling of gender intergroup relations and/or children’s self-guided interests about gender (self-socialization) contribute to the formation of gender attitudes, status perceptions, and gender intergroup behaviors among young 4- to 6-year-old children. Our participant sample also allowed us to explore variation by child gender, ethnicity (Asian-, Black-, Latiné-, and White-American), and U.S. geographical region (Northeast, Pacific Northwest, West, Southeast, and Hawaii). Data suggest that children whose parents reported they were especially active in seeking information about gender tended to allocate more resources to same-gender versus other-gender children and expressed less positive evaluations of other-gender children in comparison to children who were less active. By contrast, we found that parents’ conversations with their children about gender intergroup relations and about gender-play stereotypes showed few connections with children’s gender attitudes. In terms of demographic differences, boys raised in households with more unequal versus equal division of labor perceived that men had higher status than women, but few differences by ethnicity or geographic region emerged. In sum, our study suggests that both self- and parent socialization processes are at play in shaping early gender attitudes, status perceptions, and gender intergroup behavior, although self-socialization seemed to play a larger role.

Across three pre-registered studies (n = 221 4-9-year olds, 51% female; 218 parents, 80% female; working- and middle-class backgrounds; data collected during 2019-2021) conducted in the United States (Studies 1-2; 74% White) and China (Study 3; 100% Asian), we document the emergence of a preference for "strivers." Beginning at age 7, strivers (who work really hard) were favored over naturals (who are really smart) in both cultures (R2 ranging .03-.11). We explored several lay beliefs surrounding this preference. Beliefs about outcomes and the controllability of effort predicted the striver preference: Children who expected strivers to be more successful than naturals and believed effort was more controllable than talent preferred strivers more. Implications of the striver preference in education and beyond are discussed.