







Abstract When do descriptive regularities (what characteristics individuals have) become prescriptive norms (what characteristics individuals should have)? We examined children's (4–13 years) and adults' use of group regularities to make prescriptive judgments, employing novel groups (Hibbles and Glerks) that engaged in morally neutral behaviors (e.g., eating different kinds of berries). Participants were introduced to conforming or non‐conforming individuals (e.g., a Hibble who ate berries more typical of a Glerk). Children negatively evaluated non‐conformity, with negative evaluations declining with age (Study 1). These effects were replicable across competitive and cooperative intergroup contexts (Study 2) and stemmed from reasoning about group regularities rather than reasoning about individual regularities (Study 3). These data provide new insights into children's group concepts and have important implications for understanding the development of stereotyping and norm enforcement.
Children's Acquisition and Application of Norms
All human societies are permeated by collectively shared entities that govern daily social interactions and promote coordination and cooperation: norms. While the study of norm development is not new to developmental psychology, it has only recently been the target of an interdisciplinary wave of research using new methodologies and (often) complementary theoretical accounts to describe and explain the origins and potentially species-unique aspects of human norm psychology. Here we review recent developmental research showing that young children swiftly acquire and infer norms in a variety of social contexts. Moreover, children actively enforce these norms, even as unaffected bystanders, when third parties do things the wrong way. This research suggests that the foundations of human norm psychology can be found in early childhood. Deeper insights into the ontogenetic roots of norm psychology may contribute to understanding the evolutionary emergence of human cooperation and its maintenance in the contemporary world.
Children’s Sense of Fairness as Equal Respect
One influential view holds that children’s sense of fairness emerges at age 8 and is rooted in the development of an aversion to unequal resource distributions. Here, we suggest two amendments to this view. First, we argue and present evidence that children’s sense of fairness emerges already at age 3 in (and only in) the context of collaborative activities. This is because, in our theoretical view, collaboration creates a sense of equal respect among partners. Second, we argue and present evidence that children’s judgments about what is fair are essentially judgments about the social meaning of the distributive act; for example, children accept unequal distributions if the procedure gave everyone an equal chance (so-called distributive justice). Children thus respond to unequal (and other) distributions not based on material concerns, but rather based on interpersonal concerns: they want equal respect.
Rethinking Norm Psychology
Norms permeate human life. Most of people’s activities can be characterized by rules about what is appropriate, allowed, required, or forbidden—rules that are crucial in making people hyper-cooperative animals. In this article, I examine the current cognitive-evolutionary account of “norm psychology” and propose an alternative that is better supported by evidence and better placed to promote interdisciplinary dialogue. The incumbent theory focuses on rules and claims that humans genetically inherit cognitive and motivational mechanisms specialized for processing these rules. The cultural-evolutionary alternative defines normativity in relation to behavior—compliance, enforcement, and commentary—and suggests that it depends on implicit and explicit processes. The implicit processes are genetically inherited and domain-general; rather than being specialized for normativity, they do many jobs in many species. The explicit processes are culturally inherited and domain-specific; they are constructed from mentalizing and reasoning by social interaction in childhood. The cultural-evolutionary, or “cognitive gadget,” perspective suggests that people alive today—parents, educators, elders, politicians, lawyers—have more responsibility for sustaining normativity than the nativist view implies. People’s actions not only shape and transmit the rules, but they also create in each new generation mental processes that can grasp the rules and put them into action.

The Psychology of Normative Cognition
From an early age, humans exhibit a tendency to identify, adopt, andenforce the norms of their local communities. Norms are the socialrules that mark out what is appropriate, allowed, required, orforbidden in different situations for various community members. Theserules are informal in the sense that although they are sometimesrepresented in formal laws, like the rule governing which side of theroad to drive on, they need not be explicitly codified to effectivelyinfluence behavior. There are rules that forbid theft or the breakingof promises, but also rules that govern how close it is appropriate tostand to someone while talking to them, or how loud one should talkduring the conversation. Thus understood, norms regulate a wide rangeof activity. They exhibit cultural variability in their prescriptionsand proscriptions, but the presence of norms in general appears to beculturally universal. Some norms exhibit characteristics that areoften associated with morality, such as a rule that applies toeveryone and prohibits causing unnecessary harm. Other norms applyonly to certain people, such as those that delimit appropriateclothing for members of different genders, or those concerning theexpectations and responsibilities ascribed to individuals who occupypositions of leadership. The norms that prevail in a community can bemore or less fair, reasonable, or impartial, and can be subject tocritique and change.
Out-group homogeneity
The out-group homogeneity effect is the perception of out-group members as more similar to one another than are in-group members, i.e. "they are alike; we are diverse".[1] Perceivers tend to have impressions about the diversity or variability of group members around those central tendencies or typical attributes of those group members. Thus, outgroup stereotypicality judgments are overestimated, supporting the view that out-group stereotypes are overgeneralizations.[2] The term "outgroup homogeneity effect", "outgroup homogeneity bias" or "relative outgroup homogeneity" have been explicitly contrasted with "outgroup homogeneity" in general,[3] the latter referring to perceived outgroup variability unrelated to perceptions of the ingroup.
The Illusion of Asymmetric Insight
The Misconception: You celebrate diversity and respect others’ points of view. The Truth: You are driven to create and form groups and then believe others are wrong just because they are oth…

The Emergence of Social Norms and Conventions
The utility of our actions frequently depends upon the beliefs and behavior of other agents. Thankfully, through experience, we learn norms and conventions that provide stable expectations for navigating our social world. Here, we review several distinct influences on their content and distribution. At the level of individuals locally interacting in dyads, success depends on rapidly adapting pre-existing norms to the local context. Hence, norms are shaped by complex cognitive processes involved in learning and social reasoning.

Choice Bracketing
When making many choices, a person can broadly bracket them by assessing the consequences of all of them taken together, or narrowly bracket them by making each choice in isolation. We integrate research conducted in a wide range of decision contexts which shows that choice bracketing is an important determinant of behavior. Because broad bracketing allows people to take into account all the consequences of their actions, it generally leads to choices that yield higher utility. The evidence that we review, however, shows that people often fail to bracket broadly when it would be feasible for them to do so. In addition to documenting the diverse effects of bracketing, we also discuss factors that determine whether people bracket narrowly or broadly. We conclude with a discussion of normative aspects of bracketing and argue that there are some situations in which narrower bracketing results in superior decision making.

A sampling model of social judgment.
Misperceptions About Others
Perceptions about others play an important role in shaping people's attitudes and behaviors, as well as social norms more broadly. This review presents a meta-analysis of the recent empirical literature that examines perceptions about others in the field, covering over a million observations for a total of 434 elicited perceptions. We document a number of stylized facts. Misperceptions about others are widespread, asymmetric, much larger when about out-group members, and positively associated with one's own attitudes. Experimental treatments to recalibrate misperceptions generally work as intended; they sometimes lead to meaningful changes in behaviors, though this often occurs only immediately after the treatments. We discuss different conceptual frameworks that could explain the origin, persistence, and rigidity of misperceptions about others. We point to several directions for future research.

Social Norms
Social norms, the informal rules that govern behavior in groups andsocieties, have been extensively studied in the social sciences.Anthropologists have described how social norms function in differentcultures (Geertz 1973), sociologists have focused on their socialfunctions and how they motivate people to act (Durkheim 1895 [1982],1950 [1957]; Parsons 1937; Parsons & Shils 1951; James Coleman1990; Hechter & Opp 2001), and economists have explored howadherence to norms influences market behavior (Akerlof 1976; Young1998a). More recently, also legal scholars have touted social norms asefficient alternatives to legal rules, as they may internalizenegative externalities and provide signaling mechanisms at little orno cost (Ellickson 1991; Posner 2000).
How social norms emerge: The interindividual actor–critic.
What people learn from punishment: A cognitive model
Authorities, from parents of toddlers to leaders of formal institutions, use punishment to communicate disapproval and enforce social norms. Ideally, from whether and how severely a transgression is punished, targets and observers infer shared social norms. Yet in light of every punitive choice, observers also evaluate the motives and legitimacy of the authority. Here, we show that the effects of punishment can only be understood by considering these inferences simultaneously. We measured human observers’ joint inferences empirically in three preregistered experiments ( N = 1 , 254 ) and developed a rational Bayesian model using an inverse planning framework that captures and explains these inferences and their interactions quantitatively and parsimoniously. When people have different priors about norms or authorities, the model predicted and we experimentally confirmed that observing punishment by the authority can sustain polarization. This work reveals the rational logic behind how people learn from punishment and a key constraint on the function of punishment in establishing shared social norms.

Indirect reciprocity undermines indirect reciprocity destabilizing large-scale cooperation
Previous models suggest that indirect reciprocity (reputation) can stabilize large-scale human cooperation [K. Panchanathan, R. Boyd, Nature 432 , 499–502 (2004)]. The logic behind these models and experiments [J. Gross et al. , Sci. Adv. 9 , eadd8289 (2023) and O. P. Hauser, A. Hendriks, D. G. Rand, M. A. Nowak, Sci. Rep. 6 , 36079 (2016)] is that a strategy in which individuals conditionally aid others based on their reputation for engaging in costly cooperative behavior serves as a punishment that incentivizes large-scale cooperation without the second-order free-rider problem. However, these models and experiments fail to account for individuals belonging to multiple groups with reputations that can be in conflict. Here, we extend these models such that individuals belong to a smaller, “local” group embedded within a larger, “global” group. This introduces competing strategies for conditionally aiding others based on their cooperative behavior in the local or global group. Our analyses reveal that the reputation for cooperation in the smaller local group can undermine cooperation in the larger global group, even when the theoretical maximum payoffs are higher in the larger global group. This model reveals that indirect reciprocity alone is insufficient for stabilizing large-scale human cooperation because cooperation at one scale can be considered defection at another. These results deepen the puzzle of large-scale human cooperation.

Groupthink
Groupthink is a psychological phenomenon that occurs within a group of people in which the desire for harmony or conformity in the group results in an irrational or dysfunctional decision-making outcome. Cohesiveness, or the desire for cohesiveness, in a group may produce a tendency among its members to agree at all costs.[1] This causes the group to minimize conflict and reach a consensus decision without critical evaluation.[2][3]
🧵New preprint: Adults often agree with their ingroup even when evidence says otherwise. Why? To find out, we studied kids, who show the same tendency but *before* political identities take hold. With developmental data, we can see the basic psychological ingredients. doi.org/10.31234/osf.io/gf38p_v1 1/11
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