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.

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).

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.

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.

With a little help from my friends? Acculturation and mental health in Arabic-speaking refugee youth living with their families.

Introduction: Refugee youth are often faced with the compounding challenges of heightened exposure to traumatic events and acculturating to a new country during a developmental period when their sense of self is still forming. This study investigated whether refugee youth's acculturation orientation (separation, integration, marginalization, and assimilation) is associated with depressive and posttraumatic stress symptoms and aimed to identify additional indicators of acculturation that may contribute to mental health. Methods: A total of 101 Arabic-speaking refugee youths (aged 14-20 years), who were living with their families and attending school in Germany, took part in the study. They answered questions concerning traumatic exposure and posttraumatic stress symptoms, depressive symptoms, and several indicators of acculturation, including cultural orientation, positive and negative intra- and intergroup contact, language skills and friendship networks. All participants were categorized into one of four acculturation orientations using median splits. Results: Kruskal-Wallis rank sum tests revealed that acculturation orientation was not significantly associated with depressive symptoms [χ2 (3, 97) = 0.519, p = 0.915] or posttraumatic stress symptoms [χ2 (3, 97) = 0.263, p = 0.967]. Regression analysis revealed that German language skills were significantly associated with lower scores of depressive symptoms (p = 0.016) and number of friends in Germany was significantly associated with lower scores of depressive (p = 0.006) and posttraumatic stress symptoms (p = 0.002), respectively. Discussion: Policies that provide refugee youth with access to language classes and social activities with peers do not only enable them to actively participate in a new society but may also have a positive effect on their mental health.

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.

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.

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.

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.

The influence of collaboration and culture on the IKEA effect: Does cocreation alter perceptions of value in British and Indian children?

Creating objects can increase our evaluation of them, even when we compare them to physically identical copies (IKEA effect). Here we evaluate the influence of collaboration on the IKEA effect in two societies-the United Kingdom and India. One hundred twenty-eight 5-to-6-year-old children (48% female, 50% British middle class, 50% Indian middle class) assembled toys in pairs. Half of the children collaborated to assemble a single toy and half assembled their own toy. In both societies, children demonstrated an IKEA effect (η2p = .19), valuing their own creation over an identical copy. This was the case regardless of whether children collaborated or worked independently. In summary, it seems that the IKEA effect is a potent bias that is present in diverse societies and is insensitive to others' contributions in a collaborative environment. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The transmission game: Testing behavioral interventions in a pandemic-like simulation.

During pandemics, effective nonpharmaceutical interventions encourage people to adjust their behavior in fast-changing environments in which exponential dynamics aggravate the conflict between the individual benefits of risk-taking and its social costs. Policy-makers need to know which interventions are most likely to promote socially advantageous behaviors. We designed a tool for initial evaluations of the effectiveness of large-scale interventions, the transmission game framework, which integrates simulations of outbreak dynamics into large-group experiments with monetary stakes. In two studies (n = 700), we found substantial differences in the effectiveness of five behavioral interventions. A simple injunctive-norms message proved most effective, followed by two interventions boosting participants' ability to anticipate the consequences of risky behavior. Interventions featuring descriptive norms or concurrent risk information failed to reduce risk-taking.

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.

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.

Universal norm psychology leads to societal diversity in prosocial behaviour and development.

Recent studies have proposed that social norms play a key role in motivating human cooperation and in explaining the unique scale and cultural diversity of our prosociality. However, there have been few studies that directly link social norms to the form, development and variation in prosocial behaviour across societies. In a cross-cultural study of eight diverse societies, we provide evidence that (1) the prosocial behaviour of adults is predicted by what other members of their society judge to be the correct social norm, (2) the responsiveness of children to novel social norms develops similarly across societies and (3) societally variable prosocial behaviour develops concurrently with the responsiveness of children to norms in middle childhood. These data support the view that the development of prosocial behaviour is shaped by a psychology for responding to normative information, which itself develops universally across societies.

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.

Social information use in adolescents: The impact of adults, peers and household composition.

Social learning strategies are key for making adaptive decisions, but their ontogeny remains poorly understood. We investigate how social information use depends on its source (adults vs. peer), and how it is shaped by household composition (extended vs. nuclear), a factor known to modulate social development. Using a simple estimation task, we show that social information strongly impacts the behaviour of adolescents aged 11 to 15 years (N = 256), especially when its source is an adult. However, social information use does not depend on household composition: the relative impact of adults and peers was similar in adolescents from both household types. Furthermore, adolescents were found to directly copy others' estimates surprisingly frequently. This study provides novel insights into adolescents' social information use and contributes to understanding the ontogeny of social learning strategies.

Children's respect for ownership across diverse societies.

Ownership is a cornerstone of many human societies and can be understood as a cooperative arrangement, where individuals refrain from taking each other's property. Owners can thus trust others to respect their property even in their absence. We investigated this principle in 5- to 7-year-olds (N = 152) from 4 diverse societies. Children participated in a resource task with a peer-partner, where we established ownership by assigning children to one side or the other of an apparatus and by marking resources with colors to help children keep track of them. When retrieving resources in the partner's presence, the majority of children took their own things and respected what belonged to their partner. A proportion of children in all societies also respected ownership in their partner's absence, although the strength of respect varied considerably across societies. We discuss implications for the development of ownership concepts and possible explanations for societal differences. (PsycINFO Database Record (c) 2019 APA, all rights reserved).