Toddlers Prefer Agents Who Help Those Facing Harder Tasks.

Capacities to understand and evaluate others' actions are fundamental to human social life. Infants and toddlers are sensitive to the costs of others' actions, infer others' values from the costs of the actions they take, and prefer those who help others to those who hinder them, but it is largely unknown whether and how cost considerations inform early understanding of third-party prosocial actions. In three experiments (N = 94), we asked whether 16-month-old toddlers value agents who selectively help those who need it most. Presented with two agents who attempted two tasks, toddlers preferentially looked to and touched someone who helped the agent in greater need, both when one agent's task required more effort and when the tasks were the same but one agent was weaker. These results provide evidence that toddlers engage in need-based evaluations of helping, applying their understanding of action utilities to their social evaluations.

Do toddlers reason about other people's experiences of objects? A limit to early mental state reasoning.

Human social life requires an understanding of the mental states of one's social partners. Two people who look at the same objects often experience them differently, as a twinkling light or a planet, a 6 or a 9, and a random cat or Cleo, their pet. Indeed, a primary purpose of communication is to share distinctive experiences of objects or events. Here, we test whether toddlers (14-15 months) are sensitive to another agent's distinctive experiences of pictures when determining the goal underlying the agent's actions in a minimally social context. We conducted nine experiments. Across seven of these experiments (n = 206), toddlers viewed either videotaped or live events in which an actor, whose perspective differed from their own, reached (i) for pictures of human faces that were upright or inverted or (ii) for pictures that depicted a rabbit or a duck at different orientations. Then either the actor or the toddler moved to a new location that aligned their perspectives, and the actor alternately reached to each of the two pictures. By comparing toddlers' looking to the latter reaches, we tested whether their goal attributions accorded with the actor's experience of the pictured objects, with their own experience of the pictured objects, or with no consistency. In no experiment did toddlers encode the actor's goal in accord with his experiences of the pictures. In contrast, in a similar experiment that manipulated the visibility of a picture rather than the experience that it elicited, toddlers (n = 32) correctly expected the actor's action to depend on what was visible and occluded to him, rather than to themselves. In a verbal version of the tasks, older children (n = 35) correctly inferred the actor's goal in both cases. These findings provide further evidence for a dissociation between two kinds of mental state reasoning: When toddlers view an actor's object-directed action under minimally social conditions, they take account of the actor's visual access to the object but not the actor's distinctive experience of the object.

Infants rationally infer the goals of other people's reaches in the absence of first-person experience with reaching actions.

Does knowledge of other people's minds grow from concrete experience to abstract concepts? Cognitive scientists have hypothesized that infants' first-person experience, acting on their own goals, leads them to understand others' actions and goals. Indeed, classic developmental research suggests that before infants reach for objects, they do not see others' reaches as goal-directed. In five experiments (N = 117), we test an alternative hypothesis: Young infants view reaching as undertaken for a purpose but are open-minded about the specific goals that reaching actions are aimed to achieve. We first show that 3-month-old infants, who cannot reach for objects, lack the expectation that observed acts of reaching will be directed to objects rather than to places. Infants at the same age learned rapidly, however, that a specific agent's reaching action was directed either to an object or to a place, after seeing the agent reach for the same object regardless of where it was, or to the same place regardless of what was there. In a further experiment, 3-month-old infants did not demonstrate such inferences when they observed an actor engaging in passive movements. Thus, before infants have learned to reach and manipulate objects themselves, they infer that reaching actions are goal-directed, and they are open to learning that the goal of an action is either an object or a place. RESEARCH HIGHLIGHTS: In the present experiments, 3-month-old prereaching infants learned to attribute either object goals or place goals to other people's reaching actions. Prereaching infants view agents' actions as goal-directed, but do not expect these acts to be directed to specific objects, rather than to specific places. Prereaching infants are open-minded about the specific goal states that reaching actions aim to achieve.

Infants and toddlers leverage their understanding of action goals to evaluate agents who help others.

Why do infants and toddlers prefer helpers? Four experiments (conducted from 2019-2022; n = 136, 66% White, 15% Asian, 4% Black, 2% Hispanic/Latino, 13% multiracial, majority USA) investigated whether infants and toddlers favor agents whose actions allow others to achieve their goals. In the key experiment, 8-month-old infants and 15-month-old toddlers viewed a protagonist who tried and failed to open a box that contained a toy while two other agents (helpers) observed; then the toys were exchanged and the helpers opened different boxes. Infants and toddlers differently evaluated the two helpers, consistent with their developing means-end understanding. Together, the present four experiments connect infants' and toddlers' evaluations of helping to their understanding of goal-directed behavior.

Socially evaluative contexts facilitate mentalizing.

Our ability to understand others' minds stands at the foundation of human learning, communication, cooperation, and social life more broadly. Although humans' ability to mentalize has been well-studied throughout the cognitive sciences, little attention has been paid to whether and how mentalizing differs across contexts. Classic developmental studies have examined mentalizing within minimally social contexts, in which a single agent seeks a neutral inanimate object. Such object-directed acts may be common, but they are typically consequential only to the object-seeking agent themselves. Here, we review a host of indirect evidence suggesting that contexts providing the opportunity to evaluate prospective social partners may facilitate mentalizing across development. Our article calls on cognitive scientists to study mentalizing in contexts where it counts.

Toddlers' social evaluations of agents who act on false beliefs.

Mature social evaluations privilege agents' intentions over the outcomes of their actions, but young children often privilege outcomes over intentions in verbal tasks probing their social evaluations. In three experiments (N = 118), we probed the development of intention-based social evaluation and mental state reasoning using nonverbal methods with 15-month-old toddlers. Toddlers viewed scenarios depicting a protagonist who sought to obtain one of two toys, each inside a different box, as two other agents observed. Then, the boxes' contents were switched in the absence of the protagonist and either in the presence or the absence of the other agents. When the protagonist returned, one agent opened the box containing the protagonist's desired toy (a positive outcome), and the other opened the other box (a neutral outcome). When both agents had observed the toys move to their current locations, the toddlers preferred the agent who opened the box containing the desired toy. In contrast, when the agents had not seen the toys move and therefore should have expected the desired toy's location to be unchanged, the toddlers preferred the agent who opened the box that no longer contained the desired toy. Thus, the toddlers preferred the agent who intended to make the protagonist's desired toy accessible, even when its action, guided by a false belief concerning that toy's location, did not produce a positive outcome. Well before children connect beliefs to social behavior in verbal tasks, toddlers engage in intention-based evaluations of social agents with false beliefs.

Early concepts of intimacy: Young humans use saliva sharing to infer close relationships.

Across human societies, people form "thick" relationships characterized by strong attachments, obligations, and mutual responsiveness. People in thick relationships share food utensils, kiss, or engage in other distinctive interactions that involve sharing saliva. We found that children, toddlers, and infants infer that dyads who share saliva (as opposed to other positive social interactions) have a distinct relationship. Children expect saliva sharing to happen in nuclear families. Toddlers and infants expect that people who share saliva will respond to one another in distress. Parents confirm that saliva sharing is a valid cue of relationship thickness in their children's social environments. The ability to use distinctive interactions to infer categories of relationships thus emerges early in life, without explicit teaching; this enables young humans to rapidly identify close relationships, both within and beyond families.

Moderated Online Data-Collection for Developmental Research: Methods and Replications.

Online data collection methods are expanding the ease and access of developmental research for researchers and participants alike. While its popularity among developmental scientists has soared during the COVID-19 pandemic, its potential goes beyond just a means for safe, socially distanced data collection. In particular, advances in video conferencing software has enabled researchers to engage in face-to-face interactions with participants from nearly any location at any time. Due to the novelty of these methods, however, many researchers still remain uncertain about the differences in available approaches as well as the validity of online methods more broadly. In this article, we aim to address both issues with a focus on moderated (synchronous) data collected using video-conferencing software (e.g., Zoom). First, we review existing approaches for designing and executing moderated online studies with young children. We also present concrete examples of studies that implemented choice and verbal measures (Studies 1 and 2) and looking time (Studies 3 and 4) across both in-person and online moderated data collection methods. Direct comparison of the two methods within each study as well as a meta-analysis of all studies suggest that the results from the two methods are comparable, providing empirical support for the validity of moderated online data collection. Finally, we discuss current limitations of online data collection and possible solutions, as well as its potential to increase the accessibility, diversity, and replicability of developmental science.

Theory of mind in context: Mental-state representations for social evaluation.

Whereas Phillips and colleagues argue that knowledge representations are more basic than belief representations, we argue that an accurate analysis of what is fundamental to theory of mind may depend crucially on the context in which mental-state reasoning occurs. Specifically, we call for increased study of the developmental trajectory of mental-state reasoning within socially evaluative contexts.

"Parental" responses to human infants (and puppy dogs): Evidence that the perception of eyes is especially influential, but eye contact is not.

The present investigation tests: (i) whether the perception of an human infant's eyes, relative to other facial features, especially strongly elicits "parental" responses (e.g., appraisals of cuteness and vulnerability); (ii) if, so, whether effects of the visual perception of eyes may be partially attributable to eye contact; (iii) whether the perception of non-human animals' (puppy dogs') eyes also especially strongly influence appraisals of their cuteness and vulnerability; and (iv) whether individual differences in caregiving motives moderate effects. Results from 5 experiments (total N = 1458 parents and non-parents) provided empirical evidence to evaluate these hypotheses: Appraisals of human infants were influenced especially strongly by the visual perception of human infants' eyes (compared to other facial features); these effects do not appear to be attributable to eye contact; the visual perception of eyes influenced appraisals of puppy dogs, but not exactly in the same way that it influenced appraisals of human infants; and there was no consistent evidence of moderation by individual differences in caregiving motives. These results make novel contributions to several psychological literatures, including literatures on the motivational psychology of parental care and on person perception.

Social evaluation of intentional, truly accidental, and negligently accidental helpers and harmers by 10-month-old infants.

Whereas adults largely base their evaluations of others' actions on others' intentions, a host of research in developmental psychology suggests that younger children privilege outcome over intention, leading them to condemn accidental harm. To date, this question has been examined only with children capable of language production. In the current studies, we utilized a non-linguistic puppet show paradigm to examine the evaluation of intentional and accidental acts of helping or harming in 10-month-old infants. In Experiment 1 (n=64), infants preferred intentional over accidental helpers but accidental over intentional harmers, suggestive that by this age infants incorporate information about others' intentions into their social evaluations. In Experiment 2 (n=64), infants did not distinguish "negligently" accidental from intentional helpers or harmers, suggestive that infants may find negligent accidents somewhat intentional. In Experiment 3 (n=64), we found that infants preferred truly accidental over negligently accidental harmers, but did not reliably distinguish negligently accidental from truly accidental helpers, consistent with past work with adults and children suggestive that humans are particularly sensitive to negligently accidental harm. Together, these results imply that infants engage in intention-based social evaluation of those who help and harm accidentally, so long as those accidents do not stem from negligence.

The limits of early social evaluation: 9-month-olds fail to generate social evaluations of individuals who behave inconsistently.

Infant studies examining the development of the ability to evaluate others for their pro- and antisocial acts to date have explored how infants evaluate individuals who are either consistently prosocial or consistently antisocial. Yet in the real world, one regularly encounters individuals who behave inconsistently, engaging in multiple different kinds of behaviors that are variably prosocial and antisocial. In order to form accurate social evaluations of these inconsistently helpful and harmful individuals, then, evaluators must be able to aggregate across different types of behaviors and update previously formed evaluations based on new information. The current studies were designed to examine 9-month-old infants' social evaluations of characters who have displayed both prosocial and antisocial acts. Across three experiments using a previously utilized scenario for testing infants' preference for prosocial over antisocial others, infants repeatedly failed to prefer more- versus less-prosocial individuals when one of those individuals had previously acted both prosocially and antisocially, despite various attempts to facilitate responding across experiments. Notably, an additional experiment replicated infants' preference for consistently prosocial over consistently antisocial others. Together, findings from the current studies suggest that incorporating behavioral inconsistency into one's social evaluations may be especially difficult for infants in the first year.