Toddlers imitate prosocial demonstrations in bystander but not transgressor contexts.

Although prosocial abilities are associated with a wide range of healthy outcomes, few studies have experimentally examined socialization practices that may cause increased prosocial responding. The purpose of this study was to investigate conditions under which 2- and 3-year-old children can acquire prosocial behaviors through imitation. In Study 1 (N = 53), toddlers in the experimental condition watched a video of an adult comfort a woman in distress by performing a novel prosocial action without depicting how the woman was hurt. Parents then pretended they hurt their own finger and feigned distress. Children in the experimental condition were more likely to imitate the novel action relative to two control groups: (a) children who did not watch the video but witnessed a distressed parent, and (b) children who watched the video but witnessed parents engage in a neutral interaction. Thus, in a bystander context where children witnessed parent distress, toddlers imitated a general demonstration of how to respond prosocially to distress and applied this information to a specific distress scenario. In Study 2 (N = 54), the procedures were identical to those in the first study except that children were led to believe that they had transgressed to cause parent distress. In a transgressor context, children in the experimental condition were not more likely to imitate the prosocial behavior relative to children in either control group. These studies demonstrate that whether or not children have caused a victim's distress greatly affects their ability to apply a socially learned prosocial behavior, possibly due to self-conscious emotions such as guilt and shame.

Emotional Contexts Influence Toddlers' Prosocial Strategies.

Prosocial behavior is a highly heterogeneous construct, and young children use distinct prosocial actions in response to differing emotional needs of another person. This study examined whether toddlers' prosocial responses differed in response to two understudied emotional contexts-whether or not children caused a victim's distress, and the specific emotion expressed by the victim. Toddlers (N = 86; M age =35 months) and their parent participated in two separate mishap paradigms in which parents feigned pain and sadness, respectively. Half of the sample was led to believe they had transgressed to cause their parent's distress, whereas the other half simply witnessed parent distress as bystanders. Results indicated that toddlers were overall equally prosocial when they were transgressors compared to when they were bystanders, and significantly more prosocial in response to sadness than pain Toddlers were significantly more likely to use affection as transgressors than bystanders, information seeking as bystanders than transgressors, and affection in response to pain than sadness. All children used greater helping in response to sadness than pain, and this was especially true when they were bystanders. Findings add to mounting evidence of the complexity of prosocial action in early childhood by identifying that two, distinct emotional contexts influence the amount and type of prosocial behaviors that toddlers use to help others.

Preschool physics: Using the invisible property of weight in causal reasoning tasks.

Causal reasoning is an important aspect of scientific thinking. Even young human children can use causal reasoning to explain observations, make predictions, and design actions to bring about specific outcomes in the physical world. Weight is an interesting type of cause because it is an invisible property. Here, we tested preschool children with causal problem-solving tasks that assessed their understanding of weight. In an experimental setting, 2- to 5-year-old children completed three different tasks in which they had to use weight to produce physical effects-an object displacement task, a balance-scale task, and a tower-building task. The results showed that the children's understanding of how to use object weight to produce specific object-to-object causal outcomes improved as a function of age, with 4- and 5-year-olds showing above-chance performance on all three tasks. The younger children's performance was more variable. The pattern of results provides theoretical insights into which aspects of weight processing are particularly difficult for preschool children and why they find it difficult.

Do Children Understand Iconic Gestures About Events as Early as Iconic Gestures About Entities?

Children can understand iconic co-speech gestures that characterize entities by age 3 (Stanfield et al. in J Child Lang 40(2):1-10, 2014; e.g., "I'm drinking" [Formula: see text] tilting hand in C-shape to mouth as if holding a glass). In this study, we ask whether children understand co-speech gestures that characterize events as early as they do so for entities, and if so, whether their understanding is influenced by the patterns of gesture production in their native language. We examined this question by studying native English speaking 3- to 4 year-old children and adults as they completed an iconic co-speech gesture comprehension task involving motion events across two studies. Our results showed that children understood iconic co-speech gestures about events at age 4, marking comprehension of gestures about events one year later than gestures about entities. Our findings also showed that native gesture production patterns influenced children's comprehension of gestures characterizing such events, with better comprehension for gestures that follow language-specific patterns compared to the ones that do not follow such patterns-particularly for manner of motion. Overall, these results highlight early emerging abilities in gesture comprehension about motion events.

Adding sound to theory of mind: Comparing children's development of mental-state understanding in the auditory and visual realms.

Theory of mind (ToM) gradually develops during the preschool years. Measures of ToM usually target visual experience, but auditory experiences also provide valuable social information. Given differences between the visual and auditory modalities (e.g., sights persist, sounds fade) and the important role environmental input plays in social-cognitive development, we asked whether modality might influence the progression of ToM development. The current study expands Wellman and Liu's ToM scale (2004) by testing 66 preschoolers using five standard visual ToM tasks and five newly crafted auditory ToM tasks. Age and gender effects were found, with 4- and 5-year-olds demonstrating greater ToM abilities than 3-year-olds and girls passing more tasks than boys; there was no significant effect of modality. Both visual and auditory tasks formed a scalable set. These results indicate that there is considerable consistency in when children are able to use visual and auditory inputs to reason about various aspects of others' mental states.

Brief Report: Imitation of Object-Directed Acts in Young Children with Autism Spectrum Disorders.

Children with autism spectrum disorders (ASD) imitate less than typically developing (TD) children; however, the specific features and causes of this deficit are still unclear. The current study investigates the role of joint engagement, specifically children's visual attention to demonstrations, in an object-directed imitation task. This sample was recruited from an early ASD screening study, which allows for an examination of these behaviors prior to formal diagnosis and ASD-specific intervention. Children with ASD imitated less than TD children; children with other developmental delays showed no significant difference from the two other screen-positive groups. Additionally, only the ASD group showed decreased visual attention, suggesting that early visual attention plays a role in the social learning of children with ASD.

Imitation as a mechanism in cognitive development: a cross-cultural investigation of 4-year-old children's rule learning.

Children learn about the social and physical world by observing other people's acts. This experiment tests both Chinese and American children's learning of a rule. For theoretical reasons we chose the rule of categorizing objects by the weight. Children, age 4 years, saw an adult heft four visually-identical objects and sort them into two bins based on an invisible property-the object's weight. Children who saw this categorization behavior were more likely to sort those objects by weight than were children who saw control actions using the same objects and the same bins. Crucially, children also generalized to a novel set of objects with no further demonstration, suggesting rule learning. We also report that high-fidelity imitation of the adult's "hefting" acts may give children crucial experience with the objects' weights, which could then be used to infer the more abstract rule. The connection of perception, action, and cognition was found in children from both cultures, which leads to broad implications for how the imitation of adults' acts functions as a lever in cognitive development.

Social learning promotes understanding of the physical world: Preschool children's imitation of weight sorting.

We investigated whether social learning, specifically imitation, can advance preschoolers' understanding of weight. Preschoolers were randomly assigned to experimental and control groups. The experimental group saw an adult intentionally categorize an array of four visually identical objects based on weight. Then, children's weight-based sorting of the objects was evaluated. To test generalization, children were presented with novel objects (differing in shape, color, and weight from the original ones) and not shown what to do with them. Results indicate that 48-month-olds learned to sort by weight via observing the adult's demonstration of categorization and that children generalized weight sorting to novel objects. This shows that children imitate at a more abstract level than merely motor actions. They learn and imitate generalizable rules. 36-month-olds did not succeed on this weight sorting task. Children's cognitive development constrains what children learn through social observation and imitation.

Gambling primates: reactions to a modified Iowa Gambling Task in humans, chimpanzees and capuchin monkeys.

Humans will, at times, act against their own economic self-interest, for example, in gambling situations. To explore the evolutionary roots of this behavior, we modified a traditional human gambling task, the Iowa Gambling Task (IGT), for use with chimpanzees, capuchin monkeys and humans. We expanded the traditional task to include two additional payoff structures to fully elucidate the ways in which these primate species respond to differing reward distributions versus overall quantities of rewards, a component often missing in the existing literature. We found that while all three species respond as typical humans do in the standard IGT payoff structure, species and individual differences emerge in our new payoff structures. Specifically, when variance avoidance and reward maximization conflicted, roughly equivalent numbers of apes maximized their rewards and avoided variance, indicating that the traditional payoff structure of the IGT is insufficient to disentangle these competing strategies. Capuchin monkeys showed little consistency in their choices. To determine whether this was a true species difference or an effect of task presentation, we replicated the experiment but increased the intertrial interval. In this case, several capuchin monkeys followed a reward maximization strategy, while chimpanzees retained the same strategy they had used previously. This suggests that individual differences in strategies for interacting with variance and reward maximization are present in apes, but not in capuchin monkeys. The primate gambling task presented here is a useful methodology for disentangling strategies of variance avoidance and reward maximization.

Child-directed action promotes 2-year-olds' imitation.

Children are voracious learners and adults are ubiquitous teachers. This project investigated whether the special infant-directed action modifications parents use when teaching their children (called "motionese" by Brand et al., Developmental Science, 2002, Vol. 5, pp. 72-83) improves 2-year-olds' imitation. Children saw an adult perform a series of acts on four novel objects using either an infant-directed style (including larger range of motion and enhanced boundary marking) or an adult-directed style. Children's imitation of the acts was higher in the infant-directed condition relative to the adult-directed condition, and both types of demonstration increased imitation relative to baseline (no demonstration). We propose that motionese provides information about actions, objects, and intentionality, thereby enhancing toddlers' observational learning.

Prospective memory in children and chimpanzees.

Prospective memory (PM) involves remembering to do something at a specific time in the future. Here, we investigate the beginnings of this ability in young children (3-year-olds; Homo sapiens) and chimpanzees (Pan troglodytes) using an analogous task. Subjects were given a choice between two toys (children) or two food items (chimpanzees). The selected item was delivered immediately, whereas the unselected item was hidden in an opaque container. After completing an ongoing quantity discrimination task, subjects could request the hidden item by asking for it (children) or by pointing to the container and identifying the item on a symbol board (chimpanzees). Children and chimpanzees showed evidence of prospective-like memory in this task, as evidenced by successful retrieval of the item at the end of the task, sometimes spontaneously with no prompting from the experimenter. These findings contribute to our understanding of PM from an ontogenetic and comparative perspective.

Learning how to help others: two-year-olds' social learning of a prosocial act.

Engaging in prosocial behaviors (acts that benefit others) is associated with many positive outcomes in children, including the development of positive peer relationships, academic achievement, and good psychological functioning. This study examined the social learning mechanisms toddlers use to acquire prosocial behaviors. This brief report presents a new experimental procedure in which 2-year-olds (28-32 months, N=30) saw a video of an adult performing a novel prosocial behavior in response to another person's distress. Children then had the opportunity to imitate and implement the behavior in response to their own parent's physical distress. Children who saw the video were more likely to perform the novel action and to display non-demonstrated prosocial behaviors relative to (a) children who did not view the video but saw a parent in distress and (b) children who saw the video but witnessed their mother engage in a neutral activity. These results suggest that toddlers imitate and emulate prosocial behaviors for social interaction and that children can apply such behaviors in appropriate situations.

Chimpanzees play the ultimatum game.

Is the sense of fairness uniquely human? Human reactions to reward division are often studied by means of the ultimatum game, in which both partners need to agree on a distribution for both to receive rewards. Humans typically offer generous portions of the reward to their partner, a tendency our close primate relatives have thus far failed to show in experiments. Here we tested chimpanzees (Pan troglodytes) and human children on a modified ultimatum game. One individual chose between two tokens that, with their partner's cooperation, could be exchanged for rewards. One token offered equal rewards to both players, whereas the other token favored the chooser. Both apes and children responded like humans typically do. If their partner's cooperation was required, they split the rewards equally. However, with passive partners--a situation akin to the so-called dictator game--they preferred the selfish option. Thus, humans and chimpanzees show similar preferences regarding reward division, suggesting a long evolutionary history to the human sense of fairness.

Own and Others' Prior Experiences Influence Children's Imitation of Causal Acts.

Young children learn from others' examples, and they do so selectively. We examine whether the efficacy of prior experiences influences children's imitation. Thirty-six-month-olds had initial experience on a causal learning task either by performing the task themselves or by watching an adult perform it. The nature of the experience was manipulated such that the actor had either an easy or a difficult experience completing the task. Next, a second adult demonstrated an innovative technique for completing it. Children who had a difficult first-person experience, and those who had witnessed another person having difficulty, were significantly more likely to adopt and imitate the adult's innovation than those who had or witnessed an easy experience. Children who observed another were also more likely to imitate than were those who had the initial experience themselves. Imitation is influenced by prior experience, both when it is obtained through one's own hands-on motor manipulation and when it derives from observing the acts of others.

Learning the rules: observation and imitation of a sorting strategy by 36-month-old children.

Two experiments were used to investigate the scope of imitation by testing whether 36-month-olds can learn to produce a categorization strategy through observation. After witnessing an adult sort a set of objects by a visible property (their color; Experiment 1) or a nonvisible property (the particular sounds produced when the objects were shaken; Experiment 2), children showed significantly more sorting by those dimensions relative to children in control groups, including a control in which children saw the sorted endstate but not the intentional sorting demonstration. The results show that 36-month-olds can do more than imitate the literal behaviors they see; they also abstract and imitate rules that they see another person use.

Prior experiences and perceived efficacy influence 3-year-olds' imitation.

Children are selective and flexible imitators. They combine their own prior experiences and the perceived causal efficacy of the model to determine whether and what to imitate. In Experiment 1, children were randomly assigned to have either a difficult or an easy experience achieving a goal. They then saw an adult use novel means to achieve the goal. Children with a difficult prior experience were more likely to imitate the adult's precise means. Experiment 2 showed further selectivity--children preferentially imitated causally efficacious versus nonefficacious acts. In Experiment 3, even after an easy prior experience led children to think their own means would be effective, they still encoded the novel means performed by the model. When a subsequent manipulation rendered the children's means ineffective, children recalled and imitated the model's means. The research shows that children integrate information from their own prior interventions and their observations of others to guide their imitation.

Precision of imitation as a function of preschoolers' understanding of the goal of the demonstration.

The authors argue that imitation is a flexible and adaptive learning mechanism in that children do not always reproduce all of the details they can from a demonstration. Instead, they vary their replications depending on their interpretation of the situation. Specifically, the authors propose that when children do not understand the overall reason for a model's behavior, they will be more likely to imitate precisely. By copying conservatively in these situations, children may have a good chance of reproducing the action of the model correctly. In contrast, when the reason for an action is clear, children will be more likely to deviate from the manners and flourishes of the model and use their own means to complete the action.