14‐Month‐olds anticipate others’ actions based on their belief about an object's identity

Past research has accumulated evidence regarding infants’ false‐belief understanding, measuring their gaze patterns or active helping behaviors. However, the underlying mechanisms are still debated, specifically, whether young infants can compute that others represent the world under a certain aspect. Such performance requires holding in mind two representations about the same object simultaneously and attributing only one to another person. While 14‐month‐olds can encode an object under different aspects when forming first‐person representations, it is unclear whether infants at this very age could also predict others’ behavior based on their beliefs about an object's identity. Here, we investigate this question in a novel eye‐tracking‐based unexpected‐identity task. We measured 14‐month‐olds’ anticipatory looks combined with their looking time, using a violation‐of‐expectation paradigm. Results show that 14‐month‐olds look longer to an actor's reach that is incongruent with her false belief about the identity of an object compared to a congruent reach. Furthermore, infants correctly anticipated the actor's reach based on her false belief. Thus, as soon as infants represent dual identities they can integrate them in belief attributions and use them for consequent behavioral predictions. Such data provide evidence for the flexibility of false‐belief attributions and support proposals arguing for infants’ rich theory‐of‐mind abilities.     

Rational Imitation in 12‐Month‐Old Infants Christiane Schwier,Catharine van Maanen,Malinda Carpenter

Gergely, Bekkering, and Király (2002) demonstrated that 14‐month‐old infants engage in “rational imitation.” To investigate the development and flexibility of this skill, we tested 12‐month‐olds on a different but analogous task. Infants watched as an adult made a toy animal use a particular action to get to an endpoint. In 1 condition there was a barrier that prevented a more straightforward action and so gave the actor no choice but to use the demonstrated action. In the other condition there was no barrier, so the actor had a free choice to use the demonstrated action or not. Twelve‐month‐olds showed the same pattern of results as in Gergely and colleagues' study: They copied the particular action demonstrated more often when the adult freely chose to use the action than when she was forced to use it. Twelve‐month‐olds, too, thus show an understanding of others' intentions as rational choices and can use this understanding in cultural learning contexts.     

Infants' Rapid Learning About Self‐Propelled Objects

Six experiments investigated 7‐month‐old infants' capacity to learn about the self‐propelled motion of an object. After observing 1 wind‐up toy animal move on its own and a second wind‐up toy animal move passively by an experimenter's hand, infants looked reliably longer at the former object during a subsequent stationary test, providing evidence that infants learned and remembered the mapping of objects and their motions. In further experiments, infants learned the mapping for different animals and retained it over a 15‐min delay, providing evidence that the learning is robust and infants' expectations about self‐propelled motion are enduring. Further experiments suggested that infants' learning was less reliable when the self‐propelled objects were novel or lacked faces, body parts, and articulated, biological motion. The findings are discussed in relation to infants' developing knowledge of object categories and capacity to learn about objects in the first year of life.     

Differences in How 12‐ and 24‐Month‐Olds Interpret the Gaze of Adults

This study examined the hypothesis that toddlers interpret an adult's head turn as evidence that the adult was looking at something, whereas younger infants interpret gaze based on an expectancy that an interesting object will be present on the side to which the adult has turned. Infants of 12 months and toddlers of 24 months were first shown that an adult head turn to the side predicted the activation of a remote‐controlled toy on that side of the room. After this connection had been demonstrated, participants were assigned to 2 conditions. In the head turn condition the toys were removed but the adult continued to produce head turns to the side. In the toy condition the adult stopped turning but the toys continued to be activated when the participant turned toward them. Results showed that, compared to 12‐month‐olds, 24‐month‐olds were more likely to continue to turn to the side when the adult continued to turn even though there was no longer anything of interest to see. In contrast, compared to 24‐month‐olds, 12‐month‐olds were, if anything, more likely to continue to turn to the side in the condition in which the adult stopped turning. The latter result was replicated in a condition in which the activation of the toy was not contingent on the child's own head turn. These results imply that the meaning of gaze following may change significantly over the 2nd year of life. For 12‐month‐olds, gaze is a useful predictor of where interesting sights may occur. In contrast, for 24‐month‐olds, gaze may be a signal that the adult is looking at something.     

The Development of Gaze Following in a Third‐Party Context

Infants follow the gaze of an individual with whom they are directly interacting by the end of the first year. By 18 months infants are capable of learning novel words in observational (or third‐party) contexts (Floor & Akhtar, 2006). To examine third‐party gaze following in 12‐ and 18‐month‐olds, the parent and experimenter engaged in a conversation while the infant was present. For 8 trials approximately every 30 sec the experimenter would turn her head to the right or left to fixate on a toy placed on either side of the room with the parent following suit. In the first experiment, the parent was seated next to the infant and the experimenter opposite, whereas in the second experiment the positions of the adults were switched. In Experiment 1, 18‐month‐olds but not 12‐month‐olds followed gaze. In Experiment 2, 12‐month‐olds acquired a tendency to follow gaze during the experimental session. These results suggest that an incipient ability to follow third‐party gaze is present by 12 months and that infants acquire a more reliable and general ability to follow the gaze of noninteractive others between 12 and 18 months.     

Eighteen‐Month‐Old Infants Correct Non‐Conforming Actions by Others

At around their third birthday, children begin to enforce social norms on others impersonally, often using generic normative language, but little is known about the developmental building blocks of this abstract norm understanding. Here, we investigate whether even toddlers show signs of enforcing on others interpersonally how “we” do things. In an initial dyad, 18‐month‐old infants learnt a simple game‐like action from an adult. In two experiments, the adult either engaged infants in a normative interactive activity (stressing that this is the way “we” do it) or, as a non‐normative control, marked the same action as idiosyncratic, based on individual preference. In a test dyad, infants had the opportunity to spontaneously intervene when a puppet partner performed an alternative action. Infants intervened, corrected, and directed the puppet more in the normative than in the non‐normative conditions. These findings suggest that, during the second year of life, infants develop second‐personal normative expectations about their partner's behavior (“You should do X!”) in social interactions, thus making an important step toward understanding the normative structure of human cultural activities. These simple normative expectations will later be scaled up to group‐minded and abstract social norms.     

Common Coding of Observation and Execution of Action in 9‐Month‐Old Infants

Do 9‐month‐old infants motorically simulate actions they perceive others perform? Two experiments tested whether action observation, like overt reaching, is sufficient to elicit the Piagetian A‐not‐B error. Infants recovered a toy hidden at location A or observed an experimenter recover the toy. After the toy was hidden at location B, infants in both conditions perseverated in reaching to A, demonstrating that active search by the infant is not necessary for the A‐not‐B error. Consistent with prior research, infants displayed an ipsilateral bias when reaching, the so‐called mysterious midline barrier. A similar ipsilateral bias was also observed depending on the manner in which the experimenter reached; infants perseverated following observation of ipsi‐ but not contralateral reaches by the experimenter. Thus, infants perseverated only following observation of actions they themselves were able to perform, suggesting that they coded others' actions in terms of motor simulation.     

Six‐ and 9‐Month‐Old Infants Discriminate Between Goals Despite Similar Action Patterns

Behne, Carpenter, Call, and Tomasello (2005) showed that 9‐ to 18‐month‐olds, but not 6‐month‐olds, differentiated between people who were unwilling and unable to share toys. As the outcome of the two tasks is the same (i.e., the toy is not shared), the infants must respond to the different goals of the actor. However, visual habituation paradigms have shown an earlier onset of goal awareness. The present study reconciles this disparity by replicating the findings of Behne et al. with both 6‐ and 9‐month‐olds, using similar tasks and additional response measures.     

Nineteen‐Month‐Olds' Understanding of the Conventionality of Object Labels Versus Desires

We assessed 19‐month‐olds' appreciation of the conventional nature of object labels versus desires. Infants played a finding game with an experimenter who stated her intention to find the referent of a novel word (word group), to find an object she wanted (desire group), or simply to look in a box (control group). A 2nd experimenter then administered a comprehension task to assess infants' tendency to extend information to a 2nd person who was not present at the time of learning. Results indicate that infants chose the target object when the 2nd experimenter asked for the referent of the novel label but not when she requested the referent of her desire. These findings demonstrate that 19‐month‐olds understand that words are conventional, but desires are not.     

Social Engagement Leads 2‐Year‐Olds to Overestimate Others’ Knowledge

Previous research has found that young children recognize an adult as being acquainted with an object most readily when the child and adult have previously engaged socially with that object together. In the current study, we tested the hypothesis that such social engagement is so powerful that it can sometimes lead children to overestimate what has been shared. After having shared two objects with an adult in turn, 2‐year‐old children played with a third object the adult could not see. In three out of four conditions, the adult remained co‐present and/or communicated to the child while she played with the third object. Children falsely perceived the adult as being acquainted with the third object when she remained co‐present (whether or not she also communicated) but not when she clearly terminated the interaction by disengaging and leaving. These results suggest that when young children are engaged with a co‐present person they tend to overestimate the other’s knowledge.     

Twelve‐Month‐Old Infants’ Sensitivity to Others’ Emotions Following Positive and Negative Events

This study investigated infants’ sensitivity to others’ congruent and incongruent emotional reactions to positive and negative events. Thirty‐six 12‐month‐old infants viewed three distinct interpersonal events (give a toy, break a toy, fight over a toy) followed by an emotional expression (happiness, sadness, anger) that was either congruent or incongruent with the preceding event outcome. The duration of infants' looking toward each emotional reaction was examined. Infants demonstrated sensitivity to incongruent emotional reactions for the give and fight events, representing the earliest evidence to date of emotional sensitivity to negative events.     

Why do Infants Look at and Use Positive Information from Some Informants Rather Than Others in Ambiguous Situations?

Three laboratory experiments on social referencing examined whether infants’ tendencies to look at and use positive information from the experimenter could be interpreted from a perspective of novelty or expertise. In Study 1, novelty was manipulated. Forty‐eight 12‐month‐old infants participated. In a between‐subject design, a more novel or a less novel experimenter presented an ambiguous object and provided positive information. The infants looked more at and regulated their behavior more in accordance with information coming from the less novel experimenter. In Study 2, expertise was manipulated. Forty‐eight 12‐month‐old infants were exposed to one experimenter who showed expertise about the laboratory situation and one experimenter who did not show such competence. The infants looked more at and regulated their behavior more in accordance with information coming from the expert. In Study 3, 40 12‐month‐old infants participated. The infants were exposed to a toy‐expert who was either novel or familiar. The infants, in both groups, looked as much at the toy‐experts and used the information regardless of whether the novel or familiar toy‐expert had provided information. The findings suggest that novelty does not increase looking in ambiguous situations. Instead, the results support the expertise perspective of infant looking preferences.     

Transfer of Social Learning Across Contexts: Exploring Infants' Attribution of Trait‐Like Emotions to Adults

We explored whether 15‐month‐olds expect another person's emotional disposition to be stable across social situations. In three observation trials, infants watched two adults interact. Half the infants saw one of the adults (“Emoter”) respond negatively to the other adult's actions (Anger group); half saw the Emoter respond neutrally to the same actions (Neutral group). After a change in social context, infants participated in novel tasks with the (now‐neutral) Emoter. Infants in the Anger group were significantly more likely to relinquish desirable toys to the Emoter. We hypothesize that, in the initial observation trials, infants learned that the Emoter was “anger‐prone” and expected her to get angry again in a new social situation. Consequently, infants readily gave the Emoter what she wanted. These findings reveal three key features of infants' affective cognition: (1) infants track adults' emotional history across encounters; (2) infants learn from observing how people interact with others and use this to form expectations about how these people will treat them; and (3) more speculatively, infants use appeasement to cope with social threat. We hypothesize that infants form “trait‐like” attributions about people's emotional dispositions and use this to formulate adaptive responses to adults in novel social contexts.     

How Manual Object Exploration is Associated with 7‐ to 8‐Month‐Old Infants’ Visual Prediction Abilities in Spatial Object Processing

The present experiment examined whether infants’ visual prediction performance of the appearance of objects moving in space is related to their manual object exploration ability. Fifty‐five 7‐ to 8‐month‐old infants were tested. A visual object prediction paradigm was developed during which a three‐dimensional object was presented in a live eye‐tracking setting. During familiarization, the object rotated back and forth along the vertical axis. While the object was moving, two target parts of it were briefly occluded from view and uncovered again as the object changed its direction of motion. In the test phase, the entire object was rotated around 90° and now rotated along the horizontal axis. We recorded infants’ eye movements directed at the target locations and analyzed the prediction rates. All of the infants also participated in a manual object exploration task, in which they freely explored five toy blocks. Infants with a higher level of object exploration skill had higher prediction rates during test trials as compared to infants with less proficient object exploratory actions. The results support the interpretation that advanced manual object exploration experience is associated with infants’ advanced visual prediction ability of the appearance of objects moving in space.     

12‐Month‐Old Infants' Perception of Attention Direction in Static Video Images

Twelve‐month‐old infants' ability to perceive gaze direction in static video images was investigated. The images showed a woman who performed attention‐directing actions by looking or pointing toward 1 of 4 objects positioned in front of her (2 on each side). When the model just pointed at the objects, she looked straight ahead, and when she just looked, her hands were hidden below the tabletop. An eye movement system (TOBII) was used to register the gaze of the participants. We found that the infants clearly discriminated the gaze directions to the objects. There was no tendency to mix up the 2 object positions, located 10° apart, on the same side of the model. The infants spent more time looking at the attended objects than the unattended ones and they shifted gaze more often from the face of the model to the attended object than to the unattended objects. Pointing did not significantly increase the infants' tendency to move gaze to the attended object, irrespective of whether the pointing gesture was accompanied by looking or not. In all conditions the infants spent most of the time looking at the model's face. This tendency was especially noticeable in the pointing‐only condition and the condition where the model just looked straight ahead.     

Pointing as Epistemic Request: 12‐month‐olds Point to Receive New Information

Infants start pointing systematically to objects or events around their first birthday. It has been proposed that infants point to an event to share their appreciation of it with others. In this study, we tested another hypothesis, according to which infants’ pointing could also serve as an epistemic request directed to the adult. Thus, infants’ motivation for pointing could include the expectation that adults would provide new information about the referent. In two experiments, an adult reacted to 12‐month‐olds’ pointing gestures by exhibiting “Informing” or “Sharing” behavior. In response, infants pointed more frequently across trials in the Informing than in the Sharing condition. This suggests that the feedback that contained new information matched infants’ expectations more than mere attention sharing. Such a result is consistent with the idea that not just the comprehension but also the production of early communicative signals is tuned to assist infants’ learning from others.     

Means‐End Behavior in Young Infants: The Interplay of Action Perception and Action Production

In 2 experiments, the interplay of action perception and action production was investigated in 6‐month‐old infants. In Experiment 1, infants received 2 versions of a means‐end task in counterbalanced order. In the action perception version, a preferential looking paradigm in which infants were shown an actor performing means‐end behavior with an expected and an unexpected outcome was used. In the action production version, infants had to pull a cloth to receive a toy. In Experiment 2, infants' ability to perform the action production task with a cloth was compared to their ability to perform the action production task with a less flexible board. Finally, Experiment 3 was designed to control for alternative low‐level explanations of the differences in the looking times toward the final states presented in Experiment 1 by only presenting the final states of the action perception task without showing the initial action sequence. Results obtained in Experiment 1 showed that in the action perception task, infants discriminated between the expected and the unexpected outcome. This perceptual ability was independent of their actual competence in executing means‐ end behavior in the action production task. Experiment 2 showed no difference in 6‐month‐olds' performance in the action production task depending on the properties of the support under the toy. Similarly, in Experiment 3, no differences in looking times between the 2 final states were found. The findings are discussed in light of theories on the development of action perception and action production.     

Can 18‐Month‐Old Infants Learn Words by Listening In on Conversations?

Previous research has shown that children as young as 2 can learn words from 3rd‐party conversations (Akhtar, Jipson, & Callanan, 2001). The focus of this study was to determine whether younger infants could learn a new word through overhearing. Novel object labels were introduced to 18‐month‐old infants in 1 of 2 conditions: directly by an experimenter or in the context of overhearing the experimenter use the word while interacting with another adult. The findings suggest that, when memory demands are not too high, 18‐month‐old infants can learn words through overhearing.     

The Goal Trumps the Means: Highlighting Goals is More Beneficial than Highlighting Means in Means‐End Training

Means‐end actions are an early‐emerging form of problem solving. These actions require initiating initial behaviors with a goal in mind. In this study, we explored the origins of 8‐month‐old infants’ means‐end action production using a cloth‐pulling training paradigm. We examined whether highlighting the goal (toy) or the means (cloth) was more valuable for learning to perform a well‐organized means‐end action. Infants were given the opportunity to both practice cloth‐pulling and view modeling of the action performed by an adult throughout the session. Infants saw either the same toy or the same cloth in successive trials, so that the goal or means were highlighted prior to modeling of the action. All infants improved throughout the session regardless of which aspect of the event was highlighted. Beyond this general improvement, repetition of goals supported more rapid learning and more sustained learning than did repetition of means. These findings provide novel evidence that, at the origins of means‐end action production, emphasizing the goal that structures an action facilitates the learning of new means‐end actions.     

It Is Not Just About Location: Infants Perseverate to Container Shape During Object Search

In searching for a toy hidden at a new location, infants will err by searching at the previously correct location. This study investigated the possibility that 8.5‐month‐old infants would perseverate on the basis of other visual features by which covers could be individuated. Infants saw a toy hidden under 1 of 2 distinctly shaped covers. Following successful retrievals from the Shape A cover, infants saw the toy hidden under the Shape B cover. On this B trial, the covers were at locations that had not been baited on the preceding trials, precluding location perseveration. The infants erred by choosing the unbaited Shape A cover more often than control infants presented with 1 type of cover throughout. The findings suggest that infants perseverate to cover shape and are form biases biased toward cover shape even when location information is sufficient to support retrieval.