Gender and cultural differences in the development of reciprocity in young children.

A foundational mechanism underlying human cooperation is reciprocity. In the context of repeated interactions with others, it is not always clear the degree to which in-kind responses reflect responsiveness to partners' prior behaviors ("reactive" responses), an interest unrelated to the partner ("nonreactive" responses), or any combination of the two. To disentangle these two types of responses, we presented children with sequential, one-shot, and costly interactions between themselves and either egalitarian or selfish peers. Study 1 tested direct, generalized, and normative reciprocal scenarios (N = 144 seven-year-old German children; 50% girls and 50% boys), finding that "nonreactive" responses were dominant for boys and manifested in the form of "selfish" resource distribution. Among girls, "reactive" responses were dominant and manifested in the form of in-kind resource distribution. Study 2 addressed even younger German children (N = 144; 4- to 8-year-old German children; 50% girls and 50% boys), exposing the same phenomenon among 4-year-olds, but not among 5.5-year-olds. Study 3 addressed 7-year-old Israeli children (N = 95; 49% girls and 51% boys), and replicated the basic phenomenon, with an additional cultural variation. The early emergence of gender differences in reciprocity and implications are discussed in cultural, socio-developmental, and evolutionary accounts. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Thought and language: Effects of group-mindedness on young children's interpretation of exclusive we.

The current study investigated whether age-related changes in the conceptualization of social groups influences interpretation of the pronoun we. Sixty-four 2- and 4-year-olds (N = 29 female, 50 White-identifying) viewed scenarios in which it was ambiguous how many puppets performed an activity together. When asked who performed the activity, a speaker puppet responded, "We did!" In one condition, the speaker was near one and distant from another puppet, implying a dyadic interpretation of we. In another condition, the speaker was distant from both, thus pulling for a group interpretation. In the former condition, 2- and 4-year-olds favored the dyadic interpretation. In the latter condition, only 4-year-olds favored the group interpretation. Age-related conceptual development "expands" the set of conceivable plural person referents.

From what I want to do to what we decided to do: 5-year-olds, but not 3-year-olds, honor their agreements with peers.

Sometimes we have a personal preference but we agree with others to follow a different course of action. In this study, 3- and 5-year-old children (N = 160) expressed a preference for playing a game one way and were then confronted with peers who expressed a different preference. The experimenter then either got the participants to agree with the peers explicitly or just shrugged her shoulders and moved on. The children were then left alone to play the game unobserved. Only the older children stuck to their agreement to play the game as the peers wished. These results suggest that by 5 years of age children's sense of commitment to agreements is strong enough to override their personal preferences.

Differences in the Social Motivations and Emotions of Humans and Other Great Apes.

Humans share with other mammals and primates many social motivations and emotions, but they are also much more cooperative than even their closest primate relatives. Here I review recent comparative experiments and analyses that illustrate humans' species-typical social motivations and emotions for cooperation in comparison with those of other great apes. These may be classified most generally as (i) 'you > me' (e.g., prosocial sympathy, informative and pedagogical motives in communication); (ii) 'you = me' (e.g., feelings of mutual respect, fairness, resentment); (iii) 'we > me' (e.g., feelings of obligation and guilt); and (iv) 'WE (in the group) > me' (e.g., in-group loyalty and conformity to norms, shame, and many in-group biases). The existence of these species-typical and species-universal motivations and emotions provides compelling evidence for the importance of cooperative activities in the human species.

A Shared Intentionality Account of Uniquely Human Social Bonding.

Many mechanisms of social bonding are common to all primates, but humans seemingly have developed some that are unique to the species. These involve various kinds of interactive experiences-from taking a walk together to having a conversation-whose common feature is the triadic sharing of experience. Current theories of social bonding have no explanation for why humans should have these unique bonding mechanisms. Here we propose a shared intentionality account of uniquely human social bonding. Humans evolved to participate with others in unique forms of cooperative and communicative activities that both depend on and create shared experience. Sharing experience in these activities causes partners to feel closer because it allows them to assess their partner's cooperative competence and motivation toward them and because the shared representations created during such interactions make subsequent cooperative interactions easier and more effective.

Apes reciprocate food positively and negatively.

Reciprocal food exchange is widespread in human societies but not among great apes, who may view food mainly as a target for competition. Understanding the similarities and differences between great apes' and humans' willingness to exchange food is important for our models regarding the origins of uniquely human forms of cooperation. Here, we demonstrate in-kind food exchanges in experimental settings with great apes for the first time. The initial sample consisted of 13 chimpanzees and 5 bonobos in the control phases, and the test phases included 10 chimpanzees and 2 bonobos, compared with a sample of 48 human children aged 4 years. First, we replicated prior findings showing no spontaneous food exchanges in great apes. Second, we discovered that when apes believe that conspecifics have 'intentionally' transferred food to them, positive reciprocal food exchanges (food-for-food) are not only possible but reach the same levels as in young children (approx. 75-80%). Third, we found that great apes engage in negative reciprocal food exchanges (no-food for no-food) but to a lower extent than children. This provides evidence for reciprocal food exchange in great apes in experimental settings and suggests that while a potential mechanism of fostering cooperation (via positive reciprocal exchanges) may be shared across species, a stabilizing mechanism (via negative reciprocity) is not.

Children's consideration of collaboration and merit when making sharing decisions in private.

Young children share equally when they acquire resources through collaboration with a partner, yet it is unclear whether they do so because in such contexts resources are encountered as common and distributed in front of the recipient or because collaboration promotes a sense of work-based fairness. In the current studies, 5- and 8-year-old children from Germany (N = 193) acquired resources either by working individually alongside or by collaborating with a peer. After finding out that the partner's container was empty, they decided in private whether they wanted to donate some resources to the peer. When both partners had worked with equal efforts (Study 1), children shared more after collaboration than after individual work. When one partner had worked with much more effort than the other (Study 2), children shared more with a harder-working partner than with a less-working partner independently of whether they had collaborated or worked individually. Younger children were more generous than older children, in particular after collaboration. These findings support the view that collaboration promotes a genuine sense of fairness in young children, but they also indicate that merit-based notions of fairness in the context of work may develop independently of collaboration, at least by the beginning of middle childhood and in Western societies.

Just teasing! - Infants' and toddlers' understanding of teasing interactions and its effect on social bonding.

The current study investigates infants' and toddlers' understanding of teasing interactions and its effect on subsequent social interactions. Teasing is a special kind of social interaction due to its dual nature: It consists of a slightly provocative contingent action accompanied by positive ostensive emotional cues. Teasing thus presents an especially interesting test case to inform us about young children's abilities to deal with complex social intentions. In a first experiment, we looked at 9-, 12-, and 18-month-old infants' ability to understand and differentiate a teasing intention from a trying intention and a refuse intention. We found that by 12 months of age, infants react differently (gaze, reach) and by 18 months they smile more in reaction to the Tease condition. In the second experiment, we tested 13-, 20- and 30-month-old children in closely matched purely playful and teasing situations. We also investigated potential social effects of teasing interactions on a subsequent affiliation sequence. Twenty- and 30-month-old children smile more in the Teasing than in the Play condition. For the 30-month-old toddlers, additionally, number of laughs is much higher in the Tease than in the Play condition. No effect on affiliation could be found. Thus, from very early in development, infants and toddlers are able to differentiate teasing from superficially similar but serious behavior and from around 18 months of age they enjoy it more. Infants and toddlers are able to process a complex social intention like teasing. Findings are discussed regarding infant and toddler intention understanding abilities.

Social cognition and metacognition in great apes: a theory.

Twenty-five years ago, at the founding of this journal, there existed only a few conflicting findings about great apes' social-cognitive skills (theory of mind). In the 2 ½ decades since, we have discovered that great apes understand the goals, intentions, perceptions, and knowledge of others, and they use this knowledge to their advantage in competitive interactions. Twenty-five years ago there existed basically no studies on great apes' metacognitive skills. In the 2 ½ decades since, we have discovered that great apes monitor their uncertainty and base their decisions on that, or else decide to gather more information to make better decisions. The current paper reviews the past 25 years of research on great ape social cognition and metacognition and proposes a theory about how the two are evolutionarily related.

Five-year-old children show cooperative preferences for faces with white sclera.

The cooperative eye hypothesis posits that human eye morphology evolved to facilitate cooperation. Although it is known that young children prefer stimuli with eyes that contain white sclera, it is unknown whether white sclera influences children's perception of a partner's cooperativeness specifically. In the current studies, we used an online methodology to present 5-year-old children with moving three-dimensional face models in which facial morphology was manipulated. Children found "alien" faces with human eyes more cooperative than faces with dark sclera (Study 2) but not faces with enlarged irises (Study 1). For more human-like faces (Study 3), children found human eyes more cooperative than either enlarged irises or dark sclera and found faces with enlarged irises cuter (but not more cooperative) than eyes with dark sclera. Together, these results provide strong support for the cooperative eye hypothesis.

Evidence for a developmental shift in the motivation underlying helping in early childhood.

We investigated children's positive emotions as an indicator of their underlying prosocial motivation. In Study 1, 2-, and 5-year-old children (N = 64) could either help an individual or watch as another person provided help. Following the helping event and using depth sensor imaging, we measured children's positive emotions through changes in postural elevation. For 2-year-olds, helping the individual and watching another person help was equally rewarding; 5-year-olds showed greater postural elevation after actively helping. In Study 2, 5-year-olds' (N = 59) positive emotions following helping were greater when an audience was watching. Together, these results suggest that 2-year-old children have an intrinsic concern that individuals be helped whereas 5-year-old children have an additional, strategic motivation to improve their reputation by helping.

Disagreement, justification, and equitable moral judgments: A brief training study.

Although theorists agree that social interactions play a major role in moral development, previous research has not experimentally assessed how specific features of social interactions affect children's moral judgments and reasoning. The current study assessed two features: disagreement and justification. In a brief training phase, children aged 4-5.5 years (N = 129) discussed simple moral scenarios about issues of fairness (how to allocate things between individuals) with a puppet who, in a between-participants factorial design, either agreed or disagreed with the children's ideas and either asked or did not ask the children to justify their ideas. Children then responded to another set of moral scenarios in a test phase that was the same for all children. Children in the "agree and do not justify" baseline condition showed an inflexible equality bias (preferring only equal allocations regardless of context), but children who had experiences of disagreement or experiences of being asked to justify themselves shifted toward making equitable decisions based on common ground norms and values. Furthermore, false belief competence was related to children's decisions and justifications. These findings support the classic Piagetian hypothesis that social interactions are a catalyst of cognitive disequilibrium and moral development.

The coordination of attention and action in great apes and humans.

Great apes can discern what others are attending to and even direct others' attention to themselves in flexible ways. But they seemingly do not coordinate their attention with one another recursively-understanding that the other is monitoring their attention just as they are monitoring hers-in acts of joint attention, at least not in the same way as young human children. Similarly, great apes collaborate with partners in many flexible ways, but they seemingly do not coordinate with others to form mutually obligating joint goals and commitments, nor regulate the collaboration via acts of intentional communication, at least not in the same way as young human children. The hypothesis defended here is that it is precisely in their capacities to coordinate attention and action with others-that is, in their capacities for shared intentionality-that humans are most clearly distinguished from other great apes. This article is part of the theme issue 'Revisiting the human 'interaction engine': comparative approaches to social action coordination'.

Great apes and human children rationally monitor their decisions.

Several species can detect when they are uncertain about what decision to make-revealed by opting out of the choice, or by seeking more information before deciding. However, we do not know whether any nonhuman animals recognize when they need more information to make a decision because new evidence contradicts an already-formed belief. Here, we explore this ability in great apes and human children. First, we show that after great apes saw new evidence contradicting their belief about which of two rewards was greater, they stopped to recheck the evidence for their belief before deciding. This indicates the ability to keep track of the reasons for their decisions, or 'rational monitoring' of the decision-making process. Children did the same at 5 years of age, but not at 3 years. In a second study, participants formed a belief about a reward's location, but then a social partner contradicted them, by picking the opposite location. This time even 3-year-old children rechecked the evidence, while apes ignored the disagreement. While apes were sensitive only to the conflict in physical evidence, the youngest children were more sensitive to peer disagreement than conflicting physical evidence.

How fairness and dominance guide young children's bargaining decisions.

Reaching agreements in conflicts is an important developmental challenge. Here, German 5-year-olds (N = 284, 49% female, mostly White, mixed socioeconomic backgrounds; data collection: June 2016-November 2017) faced repeated face-to-face bargaining problems in which they chose between fair and unfair reward divisions. Across three studies, children mostly settled on fair divisions. However, dominant children tended to benefit more from bargaining outcomes (in Study 1 and 2 but not Study 3) and children mostly failed to use leverage to enforce fairness. Communication analyses revealed that children giving orders to their partner had a bargaining advantage and that children provided and responded to fairness reasons. These findings indicate that fairness concerns and dominance are both key factors that shape young children's bargaining decisions.

Effects of "we"-framing on young children's commitment, sharing, and helping.

By around 3 years of age, collaboration induces in young children a normative sense of "we" that creates a sense of obligation (e.g., commitment, fairness) toward their collaborative partner. The current study investigated whether this normative sense of we could be induced purely verbally in 3- and 4-year-old children. Children joined a puppet at a table to draw. In one condition the puppet repeatedly framed things as "we" are going to sit at the table, "we" are going to draw, and so forth, whereas in the other condition the pronoun used was always "you." Dependent measures gauged children's commitment, resource distribution, and helping behavior toward their partner. Results showed that both 3- and 4-year-olds felt a greater sense of commitment to their partner after "we"-framing than after "you"-framing. The 4-year-olds evidenced this commitment by showing a greater reluctance to abandon their partner for a more fun game compared with the 3-year-olds. The 3-year-olds did not share this reluctance, but when they did abandon their partner they more often took leave following we-framing by "announcing" their leaving. There were no effects of we-framing on children's sharing with their partner or helping behavior. These results suggest that verbal we-framing, as compared with you-framing, is an effective means of inducing in children a sense of shared agency and commitment with a partner.

Shared intentionality, reason-giving and the evolution of human culture.

The biological approach to culture focuses almost exclusively on processes of social learning, to the neglect of processes of cultural coordination including joint action and shared intentionality. In this paper, we argue that the distinctive features of human culture derive from humans' unique skills and motivations for coordinating with one another around different types of action and information. As different levels of these skills of 'shared intentionality' emerged over the last several hundred thousand years, human culture became characterized first by such things as collaborative activities and pedagogy based on cooperative communication, and then by such things as collaborative innovations and normatively structured pedagogy. As a kind of capstone of this trajectory, humans began to coordinate not just on joint actions and shared beliefs, but on the reasons for what we believe or how we act. Coordinating on reasons powered the kinds of extremely rapid innovation and stable cumulative cultural evolution especially characteristic of the human species in the last several tens of thousands of years. This article is part of a discussion meeting issue 'The emergence of collective knowledge and cumulative culture in animals, humans and machines'.

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.

Knowledge-by-acquaintance before propositional knowledge/belief.

More basic than the authors' distinction between knowing and believing is a distinction between knowledge-by-acquaintance (I know John Smith) and propositional knowledge/belief (I know/believe that John Smith lives in Durham). This distinction provides a better account of both the comparative and developmental data.

Young children conform more to norms than to preferences.

As members of cultural groups, humans continually adhere to social norms and conventions. Researchers have hypothesized that even young children are motivated to act conventionally, but support for this hypothesis has been indirect and open to other interpretations. To further test this hypothesis, we invited 3.5-year-old children (N = 104) to help set up items for a tea party. Children first indicated which items they preferred but then heard an informant (either an adult or another child) endorse other items in terms of either conventional norms or personal preferences. Children conformed (i.e., overrode their own preference to follow the endorsement) more when the endorsements were framed as norms than when they were framed as preferences, and this was the case whether the informant was an adult or another child. The priority of norms even when stated by another child opposes the interpretation that children only conformed in deference to adult authority. These findings suggest that children are motivated to act conventionally, possibly as an adaptation for living in cultural groups.