Intergroup bias has been a pervasive phenomenon throughout human history, but its psychological underpinnings are still the subject of debate. The present work tests whether intergroup attitudes and behaviors are motivated by ingroup positivity, outgroup negativity, or both, across the first few years of life. In two studies (total N = 128), children were introduced to an ingroup doll and an outgroup doll, and interacted with each one independently in a resource allocation task. Toddlers showed both ingroup positivity and outgroup negativity (Study 1). Preschoolers shifted from this pattern, showing positivity and avoiding negativity toward both ingroup and outgroup members (Study 2). Together, these studies suggest that outgroup negativity plays a stronger role in motivating early intergroup bias than previously thought.

Bize benzeyenleri sevmek insanın doğasında vardır. Bebekler bile kendi zevklerini paylaşan bireyleri tercih eder ve zıt görüşlere sahip olanlardan hoşlanmazlar. Ancak çoğulcu toplumumuz farklılıkları kabul etmeyi ve aynı fikirde olmayanlara tahammül etmeyi gerektirir. Bebek araştırmalarındaki bulgular çeşitliliği kabul etmeyi teşvik edecek stratejilerle ilgili bilgi verebilir mi?

These studies investigate the influence of adults' explicit attention to commonalities of appearance on children's preference for individuals resembling themselves. Three findings emerged: (1) An adult's identification of two dolls' respective similarity to and difference from the child led 3-year-olds to prefer the similar doll (study 1, n = 32). (2) When the adult did not comment on similarity, children age 6 years but not younger preferred physically similar individuals (study 2, n = 68), suggesting that a spontaneous preference for physically similar others does not emerge before school age. (3) Four- but not 3-year-olds generalized an adult's pedagogical cues about similarity, leading them to prefer a self-resembling doll in a new context (study 3, n = 80). These findings collectively suggest that the preference for individuals resembling ourselves develops through a process of internalizing adults' attention to, and messages about, similarities of appearance.

Two studies examined whether children (5- and 6-year-olds; 8- and 9-year-olds, n = 214) and adults (n = 72) consider social relationship when evaluating unhelpful or helpful actions. Participants learned about a person-in-need who was (or was not) helped by someone they knew (a friend) and someone they did not know (a stranger). Older children and adults judged an unhelpful friend as meaner than an unhelpful stranger, and judged a helpful stranger as nicer than a helpful friend. Younger children did not judge an unhelpful friend as any meaner than an unhelpful stranger, and they judged a helpful friend as nicer than a helpful stranger. These findings suggest that a mature appreciation of how social relationship matters for evaluation emerges relatively late in development.

Initial attraction is often based on self-other similarity along some relevant dimension. Other work reveals that children come to base their judgments of peers on physical similarities specifically. As children mature through the preschool years they come to demonstrate spontaneous sensitivity to self-resemblance in the absence of explicit mentioning of similarity or difference. Previous research has found that young children’s preferences for self-resembling others are driven by explicit similarity messages provided by an adult. Children generalize pedagogical messages like this. It is not until 6 years of age that children spontaneously compute self-other similarity in the absence of explicit similarity messages. One explanation for our prior results is that preschool-age children are on the lookout for pedagogical messages specifically about their social environment. Yet another explanation holds that the mere flagging of the concepts same and different is sufficient to engender preferences for similar others. This explanation implies that when the concepts same and different are evoked, preschool-age children will notice and value self-other similarity. A key prerequisite for analogical reasoning, or the process of relating two distinct entities by virtue of their commonalities, is the ability to understand abstract relationships. One task often used to test this ability is known as the Relational Match-to-Sample (RMTS) task. Here, a potential application of analogical reasoning to social-cognitive development is investigated by assessing whether experience with a RMTS task implicitly directs young children’s attention to similarities in the social domain. Specifically, in Study 1, whether a RMTS task will enable children to recognize physical trait similarities between themselves and others was assessed. Here 3and 4-year-olds were focused on, as prior work shows that although THE EFFECT OF RELATIONAL REASONING 3 3-year-olds attend to similarity cues in the form of explicit messages, only by age 4 do children generalize these cues. In Study 1, it was found that neither children 3 years of age nor 4 years of age generalized similarity information from an abstract context to the social domain when primed with a RMTS task. Therefore, in Study 2, whether an explicitly pedagogical explanation of concepts of same and different through the RMTS task would affect young children’s selfresemblance preference was tested. Once again, it was found that, even when emphasizing the pedagogical component, the abstract information did not penetrate the social domain. These studies suggest that domain general processes do not account for children’s social preferences, and instead, messages need to be based on specifically social information. Implications on effective interventions to mitigate biases are discussed. THE EFFECT OF RELATIONAL REASONING 4

Two studies examined whether children (5- and 6-year-olds; 8- and 9-year-olds, n  = 214) and adults ( n  = 72) consider social relationship when evaluating unhelpful or helpful actions. Participants learned about a person-in-need who was (or was not) helped by someone they knew (a friend) and someone they did not know (a stranger). Older children and adults judged an unhelpful friend as meaner than an unhelpful stranger, and judged a helpful stranger as nicer than a helpful friend. Younger children did not judge an unhelpful friend as any meaner than an unhelpful stranger, and they judged a helpful friend as nicer than a helpful stranger. These findings suggest that a mature appreciation of how social relationship matters for evaluation emerges relatively late in development.

Previous research has demonstrated that toddlers are willing to punish those who harm others. This work, however, has predominantly focused on punishment in the form of resource reduction-taking away a resource or withholding access to a resource from an antisocial other. Here, in two studies, we examined whether 4- to 7-year-old children (N = 141) engage in direct, corporal punishment against antisocial others in third-party contexts. Children were given the opportunity to press buttons so that antisocial and prosocial puppets would be hit with a hammer. In Study 1, younger children (∼4-year-olds) hit the antisocial and prosocial puppets indiscriminately, whereas older children (∼7-year-olds) tended to preferentially hit the antisocial puppet. In Study 2, we tested a larger sample of 4- to 7-year-olds, and found that none of the children engaged in corporal punishment. Collapsing across both Studies 1 and 2 also indicated a null effect-children did not engage in third-party corporal punishment. We observed these findings even though children evaluated the antisocial puppet as mean and understood that pressing the hit button hurt the puppets. These findings suggest that children lack a strong desire to corporally punish third-party social wrongdoers. Our results illustrate the importance of considering different types of punishment in assessing the development of third-party punishment, and raise questions about the development of corporal third-party punishment.

Learning what to eat is a critical problem that humans must solve over the course of ontogeny. Recent research underscores the importance of social learning processes to the development of food preferences in infancy and early childhood, but research investigating how (and whether) learned edibility information is generalized remains inconclusive. Here we investigate whether 18-month-olds generalize socially learned information about plant edibility. Across two experiments, infants watched an adult eat fruit from one type of plant and then were presented with a choice between two new plants: one was the same type of plant the adult had eaten from, and the other was a different type of plant. Infants’ reaching and eating behavior was assessed during the choice phase. The results showed that 18-month-olds generalize edibility to the same type of plant. These findings provide new insights into the nature of human food learning processes early in development.

Objective To evaluate neurodevelopmental outcomes of preterm infants with need for Child Protective Services (CPS) supervision at hospital discharge compared with those discharged without CPS supervision. Study design For infants born at <27 weeks of gestation between 2006 and 2013, prospectively collected maternal and neonatal characteristics and 18- to 26-month corrected age follow-up data were analyzed. Bayley-III cognitive and language scores of infants with discharge CPS supervision were compared with infants without CPS supervision using regression analysis while adjusting for potentially confounding variables, including entering CPS after discharge from the hospital. Results Of the 4517 preterm infants discharged between 2006 and 2013, 255 (5.6%) were discharged with a need for CPS supervision. Mothers of infants with CPS supervision were significantly more likely to be younger, single, and gravida >= 3; to have less than a high school education; and to have a singleton pregnancy and less likely to have received prenatal care or antenatal steroids. Despite similar birth weight and medical morbidities, the CPS group had longer hospital stays compared with the non-CPS group. In adjusted analysis, cognitive scores were points lower (B = -1.94; 95% CI, -3.88 to -0.08; P = .04) in the CPS at discharge group compared with the non-CPS group. In children who entered CPS supervision after hospital discharge (an additional 106 infants), cognitive scores were 4 points lower (beta = -4.76; 95% CI, -7.47 to -2.05; P < .001) and language scores were 5 points lower (beta = -4.93; 95% CI, -8.00 to -1.86; P = .002). Conclusion Extremely preterm infants discharged from the hospital with CPS supervision or entering CPS post-discharge are at increased risk for cognitive delay at 2 years of age. Opportunities exist to intervene and potentially improve outcomes in this vulnerable group of children.

IMPORTANCE Birth weight (BW) is an important predictor of mortality and morbidity. At extremely early gestational ages (GAs), BW may influence decisions regarding initiation of resuscitation. OBJECTIVE To characterize outcomes of liveborn infants with a BW less than 400 g. DESIGN, SETTING, AND PARTICIPANTS This retrospective multicenter cohort study analyzed extremely preterm infants born between January 2008 and December 2016 within the National Institute of Child Health and Human Development Neonatal Research Network. Infants with a BW less than 400 g and a GA of 22 to 26 weeks were included. Active treatment was defined as the provision of any potentially lifesaving intervention after birth. Survival was analyzed for the entire cohort; neurodevelopmental impairment (NDI) was examined for those born between January 2008 and December 2015 (birth years with outcomes available for analysis). Neurodevelopmental impairment at 18 to 26 months' corrected age (CA) was defined as a Bayley Scales of Infant and Toddler Development, Third Edition, cognitive composite score less than 85, a motor composite score less than 85, moderate or severe cerebral palsy, gross motor function classification system score of 2 or greater, bilateral blindness, and/or hearing impairment. Data were analyzed from September 2017 to October 2018. EXPOSURES Birth weight less than 400 g. MAIN OUTCOMES AND MEASURES The primary outcome was survival to discharge among infants who received active treatment. Analysis of follow-up data was limited to infants born from 2008 to 2015 to ensure children had reached assessment age. Within this cohort, neurodevelopmental outcomes were assessed for infants who survived to 18 to 26 months' CA and returned for a comprehensive visit. RESULTS Of the 205 included infants, 121(59.0%) were female, 133 (64.9%) were singletons, and 178 (86.8%) were small for gestational age. Almost half (101of 205 [49.3%]) received active treatment at birth. A total of 26 of 205 infants (12.7%; 95% CI, 8.5-18.9) overall survived to discharge, and 26 of 101 actively treated infants (25.7%; 95% CI, 17.6-35.4) survived to discharge. Within the subset of infants with a BW less than 400 g and a GA of 22 to 23 weeks, 6 of 36 actively treated infants (17%; 95% CI, 6-33) survived to discharge. Among infants born between 2008 and 2015, 23 of 90 actively treated infants (26%; 95% CI, 17-36) survived to discharge. Two infants died after discharge, and 2 were lost to follow-up. Thus, 19 of 90 actively treated infants (21%; 95% CI, 13-31) were evaluated at 18 to 26 months' CA. Moderate or severe NDI occurred in 14 of 19 infants (74%). CONCLUSIONS AND RELEVANCE Infants born with a BW less than 400 g are at high risk of mortality and significant morbidity. Although 21% of infants survived to 18 to 26 months' CA with active treatment, NDI was common among survivors.

Objective To assess the frequency of gastrostomy tube (GT) placement in extremely low birth weight (ELBW) infants, associated comorbidities, and long-term outcomes. Study design Analysis of ELBW infants from 25 centers enrolled in the National Institute of Child Health and Human Development Neonatal Research Network's Generic Database and Follow-up Registry from 2006 to 2012. Frequency of GT placement before 18-22 months, demographic and medical factors associated with GT placement, and associated long-term outcomes at 18-22 months of corrected age were described. Associations between GT placement and neonatal morbidities and long-term outcomes were assessed with logistic regression after adjustment for center and common co-variables. Results Of the 4549 ELBW infants included in these analyses, 333 (7.3%) underwent GT placement; 76% had the GT placed postdischarge. Of infants with GTs, 11 % had birth weights small for gestational age, 77% had bronchopulmonary dysplasia, and 29% severe intraventricular hemorrhage or periventricular leukomalacia. At follow-up, 56% of infants with a GT had weight <10th percentile, 61 % had neurodevelopmental impairment (NDI), and 55% had chronic breathing problems. After adjustment, small for gestational age, bronchopulmonary dysplasia, intraventricular hemorrhage/periventricular leukomalacia, poor growth, and NDI were associated with GT placement. Thirty-two percent of infants with GTs placed were taking full oral feeds at follow-up. Conclusions GT placement is common in ELBW infants, particularly among those with severe neonatal morbidities. GT placement in this population was associated with poor growth, NDI, and chronic respiratory and feeding problems at follow-up. The frequency of GT placement postneonatal discharge indicates the need for close nutritional follow-up of ELBW infants.

Evidence is presented that young human infants possess a system of numerical knowledge that consists of a mechanism for determining and representing small numbers of entities, as well as procedures for operating over these representations so as to extract information of the numerical relationships between them. A model for this mechanism is presented, and its relation to the development of further numerical knowledge is discussed.

Decades of research investigating the origins and nature of mathematical cognition suggest that humans possess a sophisticated network of neural systems for representing and manipulating symbolic and nonsymbolic numerical information, some of which we appear to share with other animal species. This article reviews behavioral and neurocognitive research describing these systems and their development in humans, highlighting the ways in which we are similar to, and different from, other species with regards to mathematical cognition.

Differences in vocal fundamental ( F 0 ) and average formant ( F n ) frequencies covary with body size in most terrestrial mammals, such that larger organisms tend to produce lower frequency sounds than smaller organisms, both between species and also across different sex and life-stage morphs within species. Here we examined whether three-month-old human infants are sensitive to the relationship between body size and sound frequencies. Using a violation-of-expectation paradigm, we found that infants looked longer at stimuli inconsistent with the relationship—that is, a smaller organism producing lower frequency sounds, and a larger organism producing higher frequency sounds—than at stimuli that were consistent with it. This effect was stronger for fundamental frequency than it was for average formant frequency. These results suggest that by three months of age, human infants are already sensitive to the biologically relevant covariation between vocalization frequencies and visual cues to body size. This ability may be a consequence of developmental adaptations for building a phenotype capable of identifying and representing an organism's size, sex and life-stage.

Many scholars draw on evidence from evolutionary biology, behavioral economics, and infant research to argue that humans are “noble savages,” endowed with indiscriminate kindness. We believe this is mistaken. While there is evidence for an early-emerging moral sense—even infants recognize and favor instances of fairness and kindness among third parties—altruistic behaviors are selective from the start. Babies and young children favor people who have been kind to them in the past and favor familiar individuals over strangers. They hold strong biases for in-group over out-group members and for themselves over others, and indeed are more unequivocally selfish than older children and adults. Much of what is most impressive about adult morality arises not through inborn capacities but through a fraught developmental process that involves exposure to culture and the exercise of rationality.

Background At birth, the release of surfactant from alveolar type II cells (ATIIs) is stimulated by increased activity of the beta-adrenergic/adenylyl cyclase/cyclic 3′-5′ adenosine monophosphate-signaling cascade. Atrial natriuretic peptide (ANP) stimulates surfactant secretion through natriuretic peptide receptor A (NPR-A). ANP inhibits adenylyl cyclase activity through its binding to NPR-C. We wished to further understand the role of the NPR-C in perinatal transition. Methods We studied ATII expression of NPR-C in fetal and newborn sheep using immunohistochemistry, and surfactant secretion in isolated ATIIs by measuring 3 [H] choline release into the media. Results ANP induced surfactant secretion, and, at higher doses, it inhibits the stimulatory effect of the secretagogue terbutaline. ATII NPR-C expression decreased significantly after birth. Premature delivery also markedly decreased ANP and NPR-C in ATIIs. Co-incubation of terbutaline (10 −4 M) with ANP (10 −6 M) significantly decreased 3 [H] choline release from isolated newborn ATII cells when compared with terbutaline alone; this inhibitory effect was mimicked by the specific NPR-C agonist, C-ANP (10 −10 M). Conclusion ANP may act as an important epithelial-derived inhibitor of surfactant release in the fetal lung, and downregulation of ANP and NPR-C following birth may sensitize ATII cells to the effects of circulating catecholamines, thus facilitating surfactant secretion.

When object A moves adjacent to a stationary object, B, and in that instant A stops moving and B starts moving, people irresistibly see this as an event in which A causes B to move. Real-world causal collisions are subject to Newtonian constraints on the relative speed of B following the collision, but here we show that perceptual constraints on the relative speed of B (which align imprecisely with Newtonian principles) define two categories of causal events in perception. Using performance-based tasks, we show that triggering events, in which B moves noticeably faster than A, are treated as being categorically different from launching events, in which B does not move noticeably faster than A, and that these categories are unique to causal events (Experiments 1 and 2). Furthermore, we show that 7- to 9-month-old infants are sensitive to this distinction, which suggests that this boundary may be an early-developing component of causal perception (Experiment 3).

When children's self-interests are at odds with their moral considerations, what do they do? In the current study of 5- and 6-year-olds (N=160), we asked (a) whether children would select the offering of a do-gooder over a neutral individual at a personal cost, (b) whether they would reject the offering of a wrongdoer over a neutral individual at a personal cost, and (c) whether these two types of decisions involve comparable levels of conflict. In the absence of material considerations, children preferred a nice character to a neutral one, but this preference was easily overcome for material gain; children accepted a larger offering from a neutral source over a smaller offering from a nice source. In contrast, children's aversion to negative characters was largely unaffected by the same material consideration; they rejected a larger offering from a mean source in favor of a smaller offering from a neutral source. In addition, children's response times indicated that deciding whether or not to "sell out" to a wrongdoer for personal gain engenders conflict but that deciding whether to take a lesser gain from a do-gooder does not. These findings indicate that children weigh both their own material interests and others' social behaviors when selecting social partners and, importantly, that an aversion to wrongdoers is a more powerful influence on these choices than an attraction to do-gooders.