Do dogs preferentially encode the identity of the target object or the location of others' actions?

The ability to make sense of and predict others' actions is foundational for many socio-cognitive abilities. Dogs (Canis familiaris) constitute interesting comparative models for the study of action perception due to their marked sensitivity to human actions. We tested companion dogs (N = 21) in two screen-based eye-tracking experiments, adopting a task previously used with human infants and apes, to assess which aspects of an agent's action dogs consider relevant to the agent's underlying intentions. An agent was shown repeatedly acting upon the same one of two objects, positioned in the same location. We then presented the objects in swapped locations and the agent approached the objects centrally (Experiment 1) or the old object in the new location or the new object in the old location (Experiment 2). Dogs' anticipatory fixations and looking times did not reflect an expectation that agents should have continued approaching the same object nor the same location as witnessed during the brief familiarization phase; this contrasts with some findings with infants and apes, but aligns with findings in younger infants before they have sufficient motor experience with the observed action. However, dogs' pupil dilation and latency to make an anticipatory fixation suggested that, if anything, dogs expected the agents to keep approaching the same location rather than the same object, and their looking times showed sensitivity to the animacy of the agents. We conclude that dogs, lacking motor experience with the observed actions of grasping or kicking performed by a human or inanimate agent, might interpret such actions as directed toward a specific location rather than a specific object. Future research will need to further probe the suitability of anticipatory looking as measure of dogs' socio-cognitive abilities given differences between the visual systems of dogs and primates.

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.

How "peer-fear" of others' evaluations can regulate young children's cooperation.

Children's cooperation with peers undergoes substantial developmental changes between 3 and 10 years of age. Here we stipulate that young children's initial fearfulness of peers' behaviour develops into older children's fearfulness of peers' evaluations of their own behaviour. Cooperation may constitute an adaptive environment in which the expressions of fear and self-conscious emotions regulate the quality of children's peer relationships.

Differences in cognitive processing? The role of verbal processes and mental effort in bilingual and monolingual children's planning performance.

Past research documents a bilingual advantage in the domain of executive functions (EFs). However, controversial debates have questioned the robustness of those behavioral differences. The current study aimed to better understand the underlying cognitive prerequisites in bilingual students as compared with monolingual students and focused on two processes: the role of verbal processes, on the one hand, and mental effort during task execution, on the other. The use of self-regulatory speech has been found to be related to performance in tasks requiring EFs. For bilinguals who have grown up with two language systems from an early age, those relations are not fully understood. Furthermore, results from neuroimaging studies have shown that bilinguals might exhibit less mental effort in EF tasks. We investigated both processes in German-speaking monolingual elementary school students (n = 33; Mage = 8.78 years) and German-Russian bilingual elementary school students (n = 34; Mage = 8.88 years) solving a planning task. Results showed that monolinguals were impaired by a verbal secondary task in comparison with a motor control condition, whereas bilinguals performed in both tasks at an equal level, indicating a differential role of self-regulatory speech in both language groups. Analyses of changes in pupil diameter revealed less mental effort during task execution for bilingual children as compared with monolingual children. The current study adds to the existing literature by supplying further evidence for cognitive differences between monolingual and bilingual children.

Preschool children's evaluations of their own unjustified requests.

To make a fair request, requesters should consider the perspective of the requestee and contrast his or her needs with their own needs. Making an unjustified request (e.g., requesting something we do not need but the requestee does need) can induce some negative feelings such as guilt. Here, we investigated whether making unjustified requests resulted in negative emotions in 3- and 5-year-old children. Participants (N = 83; 34 girls) requested resources that they did or did not need from an experimenter who either did or did not need them. Both age groups were slower and more hesitant to make an unjustified request (children did not need the sticker, but the experimenter did) and also showed lowered body posture when making an unjustified request compared with when making a justified request (children needed the sticker, but the experimenter did not). Three-year-olds showed more pronounced changes in their posture, whereas 5-year-olds' emotional expression was overall more blunted. Rather, older children relied more on verbal indirect utterances (e.g., "You've got lovely stickers"), as opposed to direct requests (e.g., "Can I have that sticker?"), when making unjustified requests. These results suggest that preschool children already apply impartial normative standards to their requests for help, account for the fairness of their requests, and consider the needs of others when requesting.

Infants' Preference for Social Interactions Increases from 7 to 13 Months of Age.

This study examined 7-to-13.5-month-old middle-class Western infants' visual orienting to third-party interactions in parallel with their social attention behavior during own social interactions (Leipzig, Germany). In Experiment 1, 9.5- to-11-month-olds (n = 20) looked longer than 7- to-8.5-month-olds (n = 20) at videos showing two adults interacting with one another when simultaneously presented with a scene showing two adults acting individually. Moreover, older infants showed higher social engagement (including joint attention) during parent-infant free play. Experiment 2 replicated this age-related increase in both measures and showed that it follows continuous trajectories from 7 to 13.5 months (n = 50). This suggests that infants' attentional orienting to others' interactions coincides with parallel developments in their social attention behavior during own social interactions.

Toddlers Prefer Adults as Informants: 2- and 3-Year-Olds' Use of and Attention to Pointing Gestures From Peer and Adult Partners.

Two- and 3-year-old children (N = 96) were tested in an object-choice task with video presentations of peer and adult partners. An immersive, semi-interactive procedure enabled both the close matching of adult and peer conditions and the combination of participants' choice behavior with looking time measures. Children were more likely to use information provided by adults. As the effect was more pronounced in the younger age-group, the observed bias may fade during toddlerhood. As there were no differences in children's propensity to follow peer and adult gestures with their gaze, these findings provide some of the earliest evidence to date that young children take an interlocutor's age into account when judging ostensively communicated testimony.

Social interaction targets enhance 13-month-old infants' associative learning.

Infants are attentive to third-party interactions, but the underlying mechanisms of this preference remain understudied. This study examined whether 13-month-old infants (N = 32) selectively learn cue-target associations guiding them to videos depicting a social interaction scene. In a visual learning task, two geometrical shapes were repeatedly paired with two kinds of target videos: two adults interacting with one another (social interaction) or the same adults acting individually (non-interactive control). Infants performed faster saccadic latencies and more predictive gaze shifts toward the cued target region during social interaction trials. These findings suggest that social interaction targets can serve as primary reinforcers in an associative learning task, supporting the view that infants find it intrinsically valuable to observe others' interactions.

Chimpanzees help others with what they want; children help them with what they need.

Humans, including young children, are strongly motivated to help others, even paying a cost to do so. Humans' nearest primate relatives, great apes, are likewise motivated to help others, raising the question of whether the motivations of humans and apes are the same. Here we compared the underlying motivation to help in human children and chimpanzees. Both species understood the situation and helped a conspecific in a straightforward situation. However, when helpers knew that what the other was requesting would not actually help her, only children gave her what she needed instead of giving her what she requested. These results suggest that both chimpanzees and human children help others but the underlying motivation for why they help differs. In comparison to chimpanzees, young children help in a paternalistic manner. The evolutionary hypothesis is that uniquely human socio-ecologies based on interdependent cooperation gave rise to uniquely human prosocial motivations to help others paternalistically.

Children learn words easier when they are interested in the category to which the word belongs.

The overall pattern of vocabulary development is relatively similar across children learning different languages. However, there are considerable differences in the words known to individual children. Historically, this variability has been explained in terms of differences in the input. Here, we examine the alternate possibility that children's individual interest in specific natural categories shapes the words they are likely to learn - a child who is more interested in animals will learn a new animal name easier relative to a new vehicle name. Two-year-old German-learning children (N = 39) were exposed to four novel word-object associations for objects from four different categories. Prior to the word learning task, we measured their interest in the categories that the objects belonged to. Our measure was pupillary change following exposure to familiar objects from these four categories, with increased pupillary change interpreted as increased interest in that category. Children showed more robust learning of word-object associations from categories they were more interested in relative to categories they were less interested in. We further found that interest in the novel objects themselves influenced learning, with distinct influences of both category interest and object interest on learning. These results suggest that children's interest in different natural categories shapes their word learning. This provides evidence for the strikingly intuitive possibility that a child who is more interested in animals will learn novel animal names easier than a child who is more interested in vehicles.

Cross-cultural variation in how much, but not whether, children overimitate.

Children from Western industrialized populations tend to copy actions modeled by an adult with high fidelity even if these actions are functionally irrelevant. This so-called overimitation has been argued to be an important driver of cumulative cultural learning. However, cross-cultural and developmental evidence on overimitation is controversial, likely due to diverging task demands regarding children's attention and memory capabilities. Here, children from a recent hunter-gatherer population (Hai||om in Namibia) were compared with urban Western children (Germany) using an overimitation procedure with minimal cognitive task demands. Although the proportion of children engaging in any overimitation was similar across the two populations, German overimitators copied irrelevant actions more persistently across tasks. These results suggest that the influence of culture on children's overimitation may be one of degree, not kind.

Toddlers' intrinsic motivation to return help to their benefactor.

A natural reaction to receiving help from someone is to help that person in return. In two studies, we investigated the developmental origins of children's motivation to return help. In Study 1, 18- and 24-month-old toddlers were either helped or not helped by an adult, and they could subsequently provide that adult with help or else observe another person providing help. We measured children's internal arousal, via changes in pupil dilation, both before and after help was provided. At both ages, children's internal arousal was higher when they could not help the adult who had previously helped them (and was lower when they could). On the other hand, if the adult needing help had not previously helped children, their internal arousal was equally low regardless of whether they or another person provided the help. Study 2 replicated this result and also found that if children had previously been helped but the person needing help was a different adult (not their benefactor), children's internal arousal was equally low regardless of whether they or another person provided the help. Together, these results suggest that young children are intrinsically motivated to return a received favor specifically to the previous benefactor, perhaps indicating a nascent sense of gratitude.

The specificity of reciprocity: Young children reciprocate more generously to those who intentionally benefit them.

Young children engage in direct reciprocity, but the mechanisms underlying such reciprocity remain unclear. In particular, prior work leaves unclear whether children's reciprocity is simply a response to receiving benefits (regardless of whether the benefits were intended) or driven by a mechanism of rewarding or preferring all benefactors (regardless of whom they benefited). Alternatively, perhaps children engage in genuine reciprocity such that they are particularly prosocial toward benefactors who intentionally provided them with benefits. Our findings support this third, richer possibility; the 3-year-olds who received benefits through the good intentions of a benefactor were subsequently more generous toward the benefactor than children who either (a) received the same benefits from the benefactor unintentionally or (b) observed the benefactor bestow the same benefits on another individual. Thus, young children are especially motivated to benefit those who have demonstrated goodwill toward them, suggesting, as one possible mechanism, an early sense of gratitude.

Toddlers Help a Peer.

Toddlers are remarkably prosocial toward adults, yet little is known about their helping behavior toward peers. In the present study with 18- and 30-month-old toddlers (n = 192, 48 dyads per age group), one child needed help reaching an object to continue a task that was engaging for both children. The object was within reach of the second child who helped significantly more often compared to a no-need control condition. The helper also fulfilled the peer's need when the task was engaging only for the child needing help. These findings suggest that toddlers' skills and motivations of helping do not depend on having a competent and helpful recipient, such as an adult, but rather they are much more flexible and general.

Children's Intrinsic Motivation to Provide Help Themselves After Accidentally Harming Others.

Little is known about the flexibility of children's prosocial motivation. Here, 2- and 3-year-old children's (n = 128) internal arousal, as measured via changes in pupil dilation, was increased after they accidentally harmed a victim but were unable to repair the harm. If they were able to repair (or if they themselves did not cause the harm and the help was provided by someone else) their arousal subsided. This suggests that children are especially motivated to help those whom they have harmed, perhaps out of a sense of guilt and a desire to reconcile with them. Young children care not only about the well-being of others but also about the relationship they have with those who depend on their help.

Young Children Want to See Others Get the Help They Need.

Children's instrumental helping has sometimes been interpreted as a desire to complete action sequences or to restore the physical order of things. Two-year-old children (n = 51) selectively retrieved for an adult the object he needed rather than one he did not (but which equally served to restore the previous order of things), and those with greater internal arousal (i.e., pupil dilation) were faster to help. In a second experiment (n = 64), children's arousal increased when they witnessed an adult respond inappropriately to another adult's need. This was not the case in a nonsocial control condition. These findings suggest that children's helping is not aimed at restoring the order of things but rather at seeing another person's need fulfilled.

Preverbal infants' understanding of social norms.

Social norms are foundational to human cooperation and co-existence in social groups. A crucial marker of social norms is that a behavior is not only shared, but that the conformity to the behavior of others is a basis for social evaluation (i.e., reinforcement and sanctioning), taking the is, how individuals usually behave, to an ought, how individuals should behave to be socially approved by others. In this preregistered study, we show that 11-month-old infants grasp this fundamental aspect about social norms already in their first year. They showed a pupillary surprise response for unexpected social responses, namely the disapproval and exclusion of an individual who showed the same behavior like others or the approval and inclusion of an individual who behaved differently. That preverbal infants link the conformity with others' behavior to social evaluations, before they respond to norm violations themselves, indicates that the foundations of social norm understanding lie in early infancy.

Observing prosociality and talent: the emotional characteristics and behavioral outcomes of elevation and admiration in 6.5- to 8.5-year-old children.

Helping and seeing others being helped elicits positive emotions in young children but little is known about the nature of these emotions, especially in middle childhood. Here we examined the specific emotional characteristics and behavioral outcomes of two closely related other-praising moral emotions: elevation and admiration. We exposed 182 6.5- to 8.5-year-old children living in New Zealand, to an elevation- and admiration-inducing video clip. Afterwards children's emotion experiences and prosocial behaviour was measured. Findings revealed higher levels of happiness, care, and warmth after seeing prosociality in others (elevation condition) and higher levels of upliftment after seeing talent in others (admiration condition). We found no differences in prosocial behavior between the elevation and admiration conditions. This is the first study to assess elevation in childhood and offers a novel paradigm to investigate the role of moral emotions as potential motivators underlying helping.

Infants' sensitivity to the congruence of others' emotions and actions.

As humans, we are attuned to the moods and emotions of others. This understanding of emotions enables us to interpret other people's actions on the basis of their emotional displays. However, the development of this capacity is not well understood. Here we show a developmental pattern in 10- and 14-month-old infants' sensitivity to others' emotions and actions. Infants were shown video clips in which happy or angry actors performed a positive action (patting a toy tiger) or a negative action (thumping the toy tiger). Only 14-month-olds, but not 10-month-olds, showed selectively greater sympathetic activity (i.e., pupil dilation) both when an angry actor performed the positive action and when a happy actor performed the negative action, in contrast to the actors performing the actions congruent with their displayed emotions. These results suggest that at the beginning of the second year of life, infants become sensitive to the congruence of other people's emotions and actions, indicating an emerging abstract concept of emotions during infancy. The results are discussed in light of previous research on emotion understanding during infancy.

Approach-avoidance orientations can predict young children's decision-making.

When facing situations that involve risk and reward, some may focus on the opportunity for reward, whereas others may focus on potential risks. Here, we used an original set of pictorial scenarios to try and predict 3- to 8-year-olds' reward-seeking and risk-avoiding behavior in three decision-making scenarios (N = 99; Mage = 5.6; 47% girls). We found that children's reward-risk tendencies did not predict sharing behavior in a dictator-game 'sharing' task. However, they predicted children's monopolizing behavior in a dictator-game 'taking' task and their preferences between taking home a 'risky' or a 'safe' reward in a novel prize-preference task. Overall, using a set of original pictorial scenarios to assess individual differences early on in development now provides initial evidence that bridges individual differences and decision-making domains and exposes behavioral patterns that were thus far hidden.