Children across societies enforce conventional norms but in culturally variable ways.

Individuals in all societies conform to their cultural group's conventional norms, from how to dress on certain occasions to how to play certain games. It is an open question, however, whether individuals in all societies actively enforce the group's conventional norms when others break them. We investigated third-party enforcement of conventional norms in 5- to 8-y-old children (n = 376) from eight diverse small-scale and large-scale societies. Children learned the rules for playing a new sorting game and then, observed a peer who was apparently breaking them. Across societies, observer children intervened frequently to correct their misguided peer (i.e., more frequently than when the peer was following the rules). However, both the magnitude and the style of interventions varied across societies. Detailed analyses of children's interactions revealed societal differences in children's verbal protest styles as well as in their use of actions, gestures, and nonverbal expressions to intervene. Observers' interventions predicted whether their peer adopted the observer's sorting rule. Enforcement of conventional norms appears to be an early emerging human universal that comes to be expressed in culturally variable ways.

Children Sustain Cooperation in a Threshold Public-Goods Game Even When Seeing Others' Outcomes.

Many societal challenges are threshold dilemmas requiring people to cooperate to reach a threshold before group benefits can be reaped. Yet receiving feedback about others' outcomes relative to one's own (relative feedback) can undermine cooperation by focusing group members' attention on outperforming each other. We investigated the impact of relative feedback compared to individual feedback (only seeing one's own outcome) on cooperation in children from Germany and India (6- to 10-year-olds, N = 240). Using a threshold public-goods game with real water as a resource, we show that, although feedback had an effect, most groups sustained cooperation at high levels in both feedback conditions until the end of the game. Analyses of children's communication (14,374 codable utterances) revealed more references to social comparisons and more verbal efforts to coordinate in the relative-feedback condition. Thresholds can mitigate the most adverse effects of social comparisons by focusing attention on a common goal.

The proximate regulation of prosocial behaviour: towards a conceptual framework for comparative research.

Humans and many other animal species act in ways that benefit others. Such prosocial behaviour has been studied extensively across a range of disciplines over the last decades, but findings to date have led to conflicting conclusions about prosociality across and even within species. Here, we present a conceptual framework to study the proximate regulation of prosocial behaviour in humans, non-human primates and potentially other animals. We build on psychological definitions of prosociality and spell out three key features that need to be in place for behaviour to count as prosocial: benefitting others, intentionality, and voluntariness. We then apply this framework to review observational and experimental studies on sharing behaviour and targeted helping in human children and non-human primates. We show that behaviours that are usually subsumed under the same terminology (e.g. helping) can differ substantially across and within species and that some of them do not fulfil our criteria for prosociality. Our framework allows for precise mapping of prosocial behaviours when retrospectively evaluating studies and offers guidelines for future comparative work.

Cheating and the effect of promises in Indian and German children.

Cheating is harmful to others and society at large. Promises have been shown to increase honesty in children, but their effectiveness has not been compared between different cultural contexts. In a study (2019) with 7- to 12-year-olds (N = 406, 48% female, middle-class), voluntary promises reduced cheating in Indian, but not in German children. Children in both contexts cheated, but cheating rates were lower in Germany than in India. In both contexts, cheating decreased with age in the (no-promise) control condition and was unaffected by age in the promise condition. These findings suggest that there may exist a threshold beyond which cheating cannot be further reduced by promises. This opens new research avenues on how children navigate honesty and promise norms.

Children over-imitate adults and peers more than puppets.

Researchers commonly use puppets in development science. Amongst other things, puppets are employed to reduce social hierarchies between child participants and adult experimenters akin to peer interactions. However, it remains controversial whether children treat puppets like real-world social partners in these settings. This study investigated children's imitation of causally irrelevant actions (i.e., over-imitation) performed by puppet, adult, or child models. Seventy-two German children (AgeRange  = 4.6-6.5 years; 36 girls) from urban, socioeconomically diverse backgrounds observed a model retrieving stickers from reward containers. The model performed causally irrelevant actions either in contact with the reward container or not. Children were more likely to over-imitate adults' and peers' actions as compared to puppets' actions. Across models, they copied contact actions more than no-contact actions. While children imitate causally irrelevant actions from puppet models to some extent, their social learning from puppets does not necessarily match their social learning from real-world social agents, such as children or adults. RESEARCH HIGHLIGHTS: We examined children's over-imitation from adult, child, and puppet models to validate puppetry as an approach to simulate non-hierarchical interactions. Children imitated adults and child models at slightly higher rates than puppets. This effect was present regardless of whether the irrelevant actions involved physical contact to the reward container or not. In our study children's social learning from puppets does not match their social learning from human models.

Simulating peers: Can puppets simulate peer interactions in studies on children's socio-cognitive development?

Interactions with peers are fundamental to socio-cognitive development, but assessing peer interactions in standardized experiments is challenging. Therefore, researchers commonly utilize puppetry to simulate peers. This Registered Report investigated urban German children's (AgeRange  = 3.5-4.5 years; N = 144; 76♀) mind ascriptions and social cognition to test whether they treat puppets like peers, adults, or neither. Children attributed less mind properties to puppets than peers or adults. However, children's social cognition (i.e., normativity, prosociality, and theory of mind) varied little across partners. Puppetry relies on children's ability for pretense, but can provide valid insights into socio-cognitive development. Implications for using puppets as stand-ins for peers in developmental research are discussed.

The missing link? How do non-human primates fit in the minimalist model of ownership?

Can Boyer's model of ownership psychology provide useful insights for comparative research? I apply his model to argue that we currently have evidence for possession psychology (based on competitive resource acquisition) in non-human primates, but not for ownership psychology.

Motor cortex activity during action observation predicts subsequent action imitation in human infants.

From early on, human infants acquire novel actions through observation and imitation. Yet, the neural mechanisms that underlie infants' action learning are not well understood. Here, we combine the assessment of infants' neural processes during the observation of novel actions on objects (i.e. transitive actions) and their subsequent imitation of those actions. Most importantly, we found that the 7-10 â€‹Hz motor cortex activity increased during action observation and predicted action imitation in 20-month-olds (n â€‹= â€‹36). 10-month-olds (n â€‹= â€‹42), who did not yet reliably imitate others' actions, showed a highly similar neural activity pattern during action observation. The presence or absence of communicative signals did neither affect infants' neural processing nor their subsequent imitation behavior. These findings provide first evidence for neural processes in the motor cortex that allow infants to acquire transitive actions from others ‒ and pinpoint a key learning mechanism in the developing brain of human infants.

Social norms and cultural diversity in the development of third-party punishment.

Human cooperation is probably supported by our tendency to punish selfishness in others. Social norms play an important role in motivating third-party punishment (TPP), and also in explaining societal differences in prosocial behaviour. However, there has been little work directly linking social norms to the development of TPP across societies. In this study, we explored the impact of normative information on the development of TPP in 603 children aged 4-14, across six diverse societies. Children began to perform TPP during middle childhood, and the developmental trajectories of this behaviour were similar across societies. We also found that social norms began to influence the likelihood of performing TPP during middle childhood in some of these societies. Norms specifying the punishment of selfishness were generally more influential than norms specifying the punishment of prosocial behaviour. These findings support the view that TPP of selfishness is important in all societies, and its development is shaped by a shared psychology for responding to normative information. Yet, the results also highlight the important role that children's prior knowledge of local norms may play in explaining societal variation in the development of both TPP and prosociality.

Children, but not great apes, respect ownership.

Access to and control of resources is a major source of costly conflicts. Animals, under some conditions, respect what others control and use (i.e. possession). Humans not only respect possession of resources, they also respect ownership. Ownership can be viewed as a cooperative arrangement, where individuals inhibit their tendency to take others' property on the condition that those others will do the same. We investigated to what degree great apes follow this principle, as compared to human children. We conducted two experiments, in which dyads of individuals could access the same food resources. The main test of respect for ownership was whether individuals would refrain from taking their partner's resources even when the partner could not immediately access and control them. Captive apes (N = 14 dyads) failed to respect their partner's claim on food resources and frequently monopolized the resources when given the opportunity. Human children (N = 14 dyads), tested with a similar apparatus and procedure, respected their partner's claim and made spontaneous verbal references to ownership. Such respect for the property of others highlights the uniquely cooperative nature of human ownership arrangements.

Children's Selective Trust in Promises.

There has been extensive research into the development of selective trust in testimony, but little is known about the development of selective trust in promises. The present research investigates children's (N = 264) selective trust in others' promises to help. In Study 1, 6-year-olds selectively trusted speakers who had previously kept a promise. In Study 2, 5-year-olds displayed selective trust for speakers who had previously kept a prosocial promise (promise to help). In Study 3, 5-year-olds trusted a speaker, who kept a prosocial promise, over a helper. These data suggest that from the age of 5 children show selective trust in others' promises using prosociality, promise keeping, or both to inform their judgments.

Give and take: Ownership affects how 2- and 3-year-olds allocate resources.

In three experiments, we investigated whether 2- and 3-year-olds (N = 240) consider ownership when taking resources for themselves and allocating resources to another agent. When selecting resources for themselves, children generally avoided taking resources that belonged to another agent and instead favored their own resources (Experiments 1 and 2). However, they did not avoid taking the agent's resources when the only other resources available were described as not belonging to the agent (Experiment 3). Children also selected fewer of the agent's resources when taking for themselves than when giving to the agent (Experiments 2 and 3). In giving to the agent, children were more likely to select the agent's resources than resources not belonging to the agent (Experiment 3). These findings show that ownership affects how 2- and 3-year-olds allocate resources. The findings also provide new evidence that 2-year-olds may respect others' ownership rights, at least to a limited degree, although we also consider an alternative explanation for the findings.

Considering self or others across two cultural contexts: How children's resource allocation is affected by self-construal manipulations.

Most humans share to some degree. Yet, from middle childhood, sharing behavior varies substantially across societies. Here, for the first time, we explored the effect of self-construal manipulation on sharing decisions in 7- and 8-year-old children from two distinct societies: urban India and urban United Kingdom. Children participated in one of three conditions that focused attention on independence, interdependence, or a control. Sharing was then assessed across three resource allocation games. A focus on independence resulted in reduced generosity in both societies. However, an intriguing societal difference emerged following a focus on interdependence, where only Indian children from traditional extended families displayed greater generosity in one of the resource allocation games. Thus, a focus on independence can move children from diverse societies toward selfishness with relative ease, but a focus on interdependence is very limited in its effectiveness to promote generosity.

Young children mostly keep, and expect others to keep, their promises.

Promises are speech acts that create an obligation to do the promised action. In three studies, we investigated whether 3- and 5-year-olds (N=278) understand the normative implications of promising in prosocial interactions. In Study 1, children helped a partner who promised to share stickers. When the partner failed to uphold the promise, 3- and 5-year-olds protested and referred to promise norms. In Study 2, when children in this same age range were asked to promise to continue a cleaning task-and they agreed-they persisted longer on the task and mentioned their obligation more frequently than without such a promise. They also persisted longer after a promise than after a cleaning reminder (Study 3). In prosocial interactions, thus, young children feel a normative obligation to keep their promises and expect others to keep their promises as well.

Late Emergence of the First Possession Heuristic: Evidence From a Small-Scale Culture.

Western preschool children often assign ownership based on first possession and some theorists have proposed that this judgment might be an early emerging, innate bias. Five- to 9-year-olds (n = 112) from a small-scale group in Kenya (Kikuyu) watched videotaped interactions of two women passing an object. The object's starting position and the women's gestures were varied. Use of the first possession heuristic increased with age, and 8- to 9-year-olds performed similarly to German 5-year-olds (n = 24). Starting position and gestures had no effect. A control study confirmed that 5-year-old Kikuyus (n = 20) understood the video material. The findings reveal that the first possession heuristic follows different developmental trajectories cross-culturally and stress the role of children's sociocultural environment.

Young dictators-Speaking about oneself decreases generosity in children from two cultural contexts.

Sharing of resources is a common feature of human societies. Yet, there is substantial societal variation in children's generosity, and this variation emerges during middle childhood. Societal differences in self-construal orientation may be one factor influencing the ontogeny of generosity. Here, we examine anonymous Dictator Game sharing in 7-and-8-year-olds from two distinct societies: India and the UK (N = 180). We used self-construal manipulations to investigate whether priming self- or other-focused conversations would differentially influence children's generosity. There were no differences in generosity between populations. While a significant reduction in generosity was found following self-priming in both societies, other-priming was ineffectual. The findings are discussed in relation to experimental features and the role of anonymity and reputational concerns.

Mealtime conversations between parents and their 2-year-old children in five cultural contexts.

Children all over the world learn language, yet the contexts in which they do so vary substantially. This variation needs to be systematically quantified to build robust and generalizable theories of language acquisition. We compared communicative interactions between parents and their 2-year-old children (N = 99 families) during mealtime across five cultural settings (Brazil, Ecuador, Argentina, Germany, and Japan) and coded the amount of talk and gestures as well as their conversational embedding (interlocutors, function, and themes). We found a comparable pattern of communicative interactions across cultural settings, which were modified in ways that are consistent with local norms and values. These results suggest that children encounter similarly structured communicative environments across diverse cultural contexts and will inform theories of language learning. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Pre-schoolers' images, intergroup attitudes, and liking of refugee peers in Germany.

There is extensive research on children's intergroup attitudes, but their perceptions of refugee children have rarely been studied. We conducted a study with 5- and 6-year-old children (N = 60) in Germany following the arrival of unprecedented large numbers of refugees in 2015 and 2016. Children completed a set of three tasks that measured their perceptions of refugee children (minority group) and German children (majority group): a draw-a-typical-child task (including questions about whether participants wanted to interact with the depicted child), an intergroup attitude task, and a liking task. Results indicate that participants drew similar pictures of and had similar intentions to interact with refugee children and German children. There was mixed evidence for group favouritism: while participants showed similar explicit attitudes towards German and refugee peers, they indicated more liking of German peers. Moreover, children viewed refugee children as a less variable (more homogeneous) group than German children. Opportunities for intergroup contact with refugee peers (i.e., whether participants attended kindergartens with or without refugee children) had no discernible effect on any of the measures. Our findings provide a snapshot of children's perceptions of refugees in a unique historical context and contribute to research on the development of intergroup attitudes in real-world settings.

Promises on the go: A field study on keeping one's word.

Promises are voluntary commitments to perform a future action and are often thought to be powerful levers for behavioral change. Here we studied the effectiveness of promises in two preregistered, incentivized field experiments with German students (N = 406) on the premises of a cafeteria. In Experiment 1, the majority of participants (63%) kept their promise to pay back at least half of a € 4-endowment, even though there was no foreseeable cost of breaking the promise, reputational or otherwise. Significantly fewer participants (22%) paid back money in a control group that faced a simple decision to return money or not. In Experiment 2, the majority of participants (54%) kept their promise to add a provided stamp to a postcard and mail it back (anonymously) within a week. We found similar return rates (52%) for a second group for which the word "promise" was omitted from the commitment. Our findings show that participants kept their word outside the laboratory while pursuing everyday activities even when there were no foreseeable negative consequences for breaking them, demonstrating that promises are effective levers for behavioral change.