I Don't Like the Tone of Your Voice: Infants Use Vocal Affect to Socially Evaluate Others

Infants can make social judgments about characters by visually observing their interactions with others (e.g., Hamlin, Wynn & Bloom, Nature, 2007, 450, 557). Here, we ask whether infants can form similar judgments about potential social partners based solely on their tone of voice. In Experiment 1, we presented 10.5‐month‐olds with two visually neutral puppets. One puppet spoke in a positive affect and the other spoke in a negative affect. When the puppets were placed within reach of the infants, infants selected the formerly positive puppet. This preference disappeared when the voices were paired with nonsocial objects (Experiment 2). In Experiment 3, 10.5‐month‐olds were once again exposed to the same emotionally negative and positive voices. However, no visual characters were present. At test, infants’ visual orientation controlled how long they heard the neutral versions of each voice. Here, infants listened longer to the neutral voice of the formerly positive speaker. That is, just as in Experiment 1, infants’ preferences for the emotionally neutral test stimuli were shaped by their earlier exposure to emotionally charged recordings of that voice. Our findings provide convergent evidence to suggest that infants possess sophisticated social evaluation abilities, preferring to interact with prosocial over antisocial others.     

Factors affecting infant toy preferences: Age,gender, experience,motor development,and parental attitude

In contrast to the anecdotal claim that “male infants like cars and female infants like dolls,” previous studies have reported mixed findings for gender‐related toy preferences in infancy. In Experiment 1, we explored the emergence of gender‐related preferences using face–car pairs (Experiment 1a, n = 51, 6–20 months) or face–stove pairs (Experiment 1b, n = 54, 6–20 months). In Experiment 2 (n = 42, 14–16 months), we explore the effect of toy properties, infants' past toy exposure, activity levels, and parental attitudes on such preferences using a wider range of toys. For both studies, infants demonstrated a general preference for faced stimuli over other objects, except for male infants who showed no preference between dolls and cars at around 15 months. Infants' prior experience participating in motor‐intensive activities, with wheeled toys and parental attitudes appeared to relate to female infants' preferences for dynamic toys. These results indicate a range of factors influence gendered toy preferences and suggest that nurture plays an important role.     

Infants' Acquisition of Grammatical Gender Dependencies

To successfully understand spoken language, listeners need to determine how words within sentences relate to one another. Although the ability to compute relationships between word categories is known to develop early in life, little research has been conducted on infants' early sensitivity to subcategorical dependencies, such as those evoked by grammatical gender (where the article form is dictated by the noun's gender). This study therefore examines whether French‐learning 18‐month‐olds track such relationships. Using the Visual Fixation Procedure, infants were presented with article–noun sequences in which the gender‐marked article either matched (e.g., la_FEM poussette_FEM “the stroller”) or mismatched (e.g., le_MASC poussette_FEM) the gender of the noun. A clear preference for correct over incorrect co‐occurrences was observed, suggesting that by 18 months of age, children's storage and access of words is sufficiently sophisticated to include the means to track subcategorical dependencies. This early sensitivity to gender information may be greatly beneficial for constraining lexical access during online language processing.     

Sensitivity to Confidence Cues Increases during the Second Year of Life

We investigated the emergence in infancy of a preference to imitate individuals who display confidence over lack of confidence. Eighteen‐ and 24‐month‐olds (N = 70) were presented with an experimenter who demonstrated the use of several objects accompanied by either nonverbal expressions of confidence or lack of confidence. At 24 months, infants were more likely to imitate the actions when demonstrated by a confident experimenter than by an unconfident experimenter; 18‐month‐olds showed no such preference. The experimenter then presented an additional imitation trial and a word‐learning trial while displaying a neutral expression. Twenty‐four‐month‐olds persisted in preferentially imitating a previously confident experimenter, but prior confidence had no effect on their word learning. These findings demonstrate a developmental increase in infants’ use of confidence cues toward the end of the second year of life.     

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.     

The early development of tempo adjustment and synchronization during joint drumming: A study of 18- to 42-month-old children

Humans have a unique ability to coordinate their rhythmic behaviors with those of others. Previous studies have demonstrated the early development of spontaneous responses to external rhythmic stimuli; however, there is little evidence regarding when and how infants begin to adjust their movement tempo and synchronize it with that of others, due to the difficulty of detecting continuous rhythmic movements of infants in a laboratory setting. In the current study, we analyzed children in age-groups of 18, 30, and 42 months and adapted a joint-drumming task used by Kirschner and Tomasello (Journal of Experimental Child Psychology, 2009, 102, 299–314). The children were enticed to play the drum under four conditions (Speed: 400 or 600 ms ISI; Partner: mother or robot). The results demonstrated that children's ability to adjust their tempo and synchronize with that of 600 ms ISI, which is slower than the spontaneous motor tempo of children at these ages, starts to develop at around 30-month-olds. We also found early evidence of this ability in 18-month-old infants who drummed with their mother. These findings indicate that children's ability for rhythmic coordination develops dynamically between 18 and 30 months of age, and a child's social partner plays an important role in facilitating this development.     

And,the Winner Is…A Visual Preference for Endpoints over Starting Points in Infants’ Motion Event Representations

Infants represent objects that are endpoints in motion events and show a preference for encoding the endpoint (the duck waddles into a bowl) over the starting point (the duck waddles out of a box). This asymmetry continues to appear in nonlinguistic cognition and language throughout development. This study tests whether this asymmetry also shows up in 16‐month‐old infants’ visual preferences for motion events, and if so, for which types of events. Infants looked longer at events depicting an “agentive” figure (e.g., duck) moving into an object (endpoint) than out of an object (starting point), and this asymmetry persisted even when the starting point object was larger and more colorful than the endpoint object and when it caused the motion of the figure. However, an asymmetry was not found when motion into/out of the endpoint/starting point involved was performed by a “nonagentive” (e.g., leaf) figure. These findings suggest that an endpoint/starting point asymmetry in infant cognition (1) extends to infants’ visual preferences of motion events, (2) shows up most strongly for events that involve an “agentive” figure, and (3) is largely unaffected by the physical saliency of the starting point object. How a visual endpoint preference may support the acquisition of spatial language is considered.     

Crawling Predicts Infants’ Understanding of Agents’ Navigation of Obstacles

We investigated whether crawling versus noncrawling infants interpret an agent's movements around an obstacle as goal‐directed. Infants (6–9 months) were habituated to a self‐propelled circle jumping over an obstacle to reach a goal. When the obstacle was removed, infants who crawled (n = 13) showed longer looking time to the familiar but now nonrational jumping path versus a novel but rational straight‐line path. Noncrawlers (n = 17) did not discriminate. Looking preference was independent of age and speed of habituation. These findings support the claim that infants’ processing of agency emerges early and applies to all agents, but stress the role of experience in the development of action interpretation.     

Online measures of looking and learning in infancy

Infants in laboratory settings look longer at events that violate their expectations, learn better about objects that behave unexpectedly, and match utterances to the objects that likely elicited them. The paradigms revealing these behaviors have become cornerstones of research on preverbal cognition. However, little is known about whether these canonical behaviors are observed outside laboratory settings. Here, we describe a series of online protocols that replicate classic laboratory findings, detailing our methods throughout. In Experiment 1a, 15-month-old infants (N = 24) looked longer at an online support event culminating in an Unexpected outcome (i.e., appearing to defy gravity) than an Expected outcome. Infants did not, however, show the same success with an online solidity event. In Experiment 1b, 15-month-old infants (N = 24) showed surprise-induced learning following online events—they were better able to learn a novel object's label when the object had behaved unexpectedly compared to when it behaved expectedly. Finally, in Experiment 2, 16-month-old infants (N = 20) who heard a valenced utterance (“Yum!”) showed preferential looking to the object most likely to have generated that utterance. Together, these results suggest that, with some adjustments, online testing is a feasible and promising approach for infant cognition research.     

Consequences of Teen Parents' Child‐Care Arrangements for Mothers and Children

Using the nationally representative Early Childhood Longitudinal Study, Birth Cohort (2001–2006; N ?7,900), the authors examined child‐care arrangements among teen parents from birth through prekindergarten. Four latent classes of child care arrangements at 9, 24, and 52 months emerged: (a) “parental care,” (b) “center care,” (c) “paid home‐based care,” and (d) “free kin‐based care.” Disadvantaged teen‐parent families were overrepresented in the “parental care” class, which was negatively associated with children's preschool reading, math, and behavior scores and mothers' socioeconomic and fertility outcomes compared with some nonparental care classes. Nonparental care did not predict any negative maternal or child outcomes, and different care arrangements had different benefits for mothers and children. Time spent in nonparental care and improved maternal outcomes contributed to children's increased scores across domains. Child‐care classes predicted maternal outcomes similarly in teen‐parent and nonteen‐parent families, but the “parental care” class predicted some disproportionately negative child outcomes for teen‐parent families.     

The Dramaturgical Model of Behavior: Its Strengths and Weaknesses*

By means of the dramaturgical model we freshly illuminate social behavior as role-like “performances” in which persons manage the impressions that others get of them. This impression management involves the concealment of data in a “dramatic” struggle with those others who wish to penetrate one's “mask.” But the chief limitations of the dramaturgical model are that it excites the invalid inferences that offstage “roles” are more like stage actors' roles than they really are, and that the person is nothing but these “roles.” The differences between onstage and offstage behavior are kept in view when the metaphorical concept of “role playing” is re-connected to its source in role playing onstage. Through an analysis of theatre and the concepts of appearance and time we conclude that while we must appear to others in a “role-like” way offstage in order to be ourselves, we are nevertheless involved in world-time offstage in a way that fundamentally distinguishes our “role-playing” from an actor's role playing. We are our “roles”, but not just our “roles.”     

Twelve months old infants' evaluation of observed comforting behavior using a choice paradigm: The role of animacy cues and self-distress

Comforting is a prosocial behavior that children start to engage in around their second year of life. There is much less known about their ability to evaluate comforting behavior of others. The current study examined whether 12 months old infants, after having watched animated abstract characters comfort or ignore a third party in distress, would show a preference for the comforting character. Using a manual choice paradigm, we found that infants were more likely to choose the comforting character than the ignoring character (Experiment 1). When the characters however lacked human surface features (eyes) infants did not show a preference (Experiment 2). Furthermore, infants self-distress during the watching of the animations did not prevent infants to evaluate the behavior of the observed characters. These findings support the idea of an early presence of “moral sense” in infancy.     

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.     

Sing for me,Mama! Infants' discrimination of novel vowels in song

When adults speak or sing with infants, they sound differently than in adult communication. Infant-directed (ID) communication helps caregivers to regulate infants' emotions and helps infants to process speech information, at least from ID-speech. However, it is largely unclear whether infants might also process speech information presented in ID-singing. Therefore, we examined whether infants discriminate vowels in ID-singing, as well as potential differences with ID-speech. Using an alternating trial preference procedure, infants aged 4–6 and 8–10 months were tested on their discrimination of an unfamiliar non-native vowel contrast presented in ID-like speech and singing. Relying on models of early speech sound perception, we expected that infants in their first half year of life would discriminate the vowels, in contrast to older infants whose non-native sound perception should deteriorate, at least in ID-like speech. Our results showed that infants of both age groups were able to discriminate the vowels in ID-like singing, while only the younger group discriminated the vowels in ID-like speech. These results show that infants process speech sound information in song from early on. They also hint at diverging perceptual or attentional mechanisms guiding infants' sound processing in ID-speech versus ID-singing toward the end of the first year of life.     

Are infants' preferences in the number change detection paradigm driven by sequence patterns?

Inter-individual differences in infants' numerosity processing have been assessed using a change detection paradigm, where participants were presented with two concurrent streams of images, one alternating between two numerosities and the other showing one constant numerosity. While most infants look longer at the changing stream in this paradigm, the reasons underlying these preferences have remained unclear. We suggest that, besides being attracted by numerosity changes, infants perhaps also respond to the alternating pattern of the changing stream. We conducted two experiments (N = 32) with 6-month-old infants to assess this hypothesis. In the first experiment, infants responded to changes in numerosity even when the changing stream showed numerosities in an unpredictable random order. In the second experiment, infants did not display any preference when an alternating stream was pitted against a random stream. These findings do not provide evidence that the alternating pattern of the changing stream contributes to drive infants' preferences. Instead, around the age of 6 months, infants' responses in the numerosity change detection paradigm appear to be mainly driven by changes in numerosity, with different levels of preference reflecting inter-individual difference in the acuity of numerosity perception.     

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.     

Learning Words Over Time: The Role of Stimulus Repetition in Mutual Exclusivity

During the second year of life, infants develop a preference to attach novel labels to novel objects. This behavior is commonly known as “mutual exclusivity” (Markman, 1989). In an intermodal preferential looking experiment with 19.5‐ and 22.5‐month‐olds, stimulus repetition was critical for observing mutual exclusivity. On the first occasion that a novel label was presented with 1 familiar object and 1 novel object, looking behavior was unsystematic. However, on reexposure to the same stimuli, 22.5‐month‐olds looked preferentially at the novel object prior to the re‐presentation of the novel label. These findings suggest a powerful memory mechanism for novel labels and objects, enabling mutual exclusivity to emerge across repeated exposures to potential referents.     

HISTORY DEPENDENCE AND THE FORMATION OF SOCIAL PREFERENCES: AN EXPERIMENTAL STUDY

We study the minimal contributing set (MCS) game, a three‐person sequential step‐level public goods game. The behavior of critical third players changes with experience in this game even though they face no strategic or payoff uncertainty. We explore why these changes occur by manipulating subjects' experience in the first half of the experiment. The treatments give subjects very different initial experiences, but all treatments move subjects' choices toward experienced subjects' play in the control sessions. Long‐run play is indistinguishable across treatments. Our results are more consistent with the “discovered preferences” hypothesis ( Plott 1996 ) than either the “constructed preference” or “reference point” hypotheses. (JEL H41, C72, C92)     

Looking Behavior at Test and Relational Memory in 6‐Month‐Old Infants

Small‐scale eye‐tracking research lends support to behavioral studies of relational memory by 6 months of life. Here, in the largest eye‐tracking test of relational memory to date (n = 276), we replicate these findings and examine the impact of excluding data based on looking behavior characteristics at test. Past work examining infants' preferential looking toward arbitrary‐paired objects and scenes has excluded infants from analysis based upon “insufficient looking” at test. Yet, research suggests that variation in looking behavior may be associated with looking patterns during encoding, as well as trait‐like differences in visual and cognitive processing. Similar to past research, we observed evidence for relational memory among 6‐month‐olds. In keeping with past research, when infants were excluded based on “insufficient looking,” we observed evidence for relational memory only when infants were tested immediately. However, when exclusion criteria were relaxed, infants specifically demonstrated preferential looking during a presumably more difficult delay‐plus‐interference condition. Moreover, analyses revealed that looking behavior during encoding was associated with looking behavior at test. Together, results suggest that infants do possess rudimentary relational memory capabilities, but that experimenters' ability to detect these capabilities is influenced by both experimental conditions and individual differences in looking behavior.