Developmental Science

Psychological essentialism is a pervasive conceptual bias to view categories as reflecting something deep, stable, and informative about their members. Scholars from diverse disciplines have long theorized that psychological essentialism has negative ramifications for inter‐group relations, yet little previous empirical work has experimentally tested the social implications of essentialist beliefs. Three studies (N = 127, ages 4.5–6) found that experimentally inducing essentialist beliefs about a novel social category led children to share fewer resources with category members, but did not lead to the out‐group dislike that defines social prejudice. These findings indicate that essentialism negatively influences some key components of inter‐group relations, but does not lead directly to the development of prejudice.

Some social groups are higher in socioeconomic status than others and the former tend to be favored over the latter. The present research investigated whether observing group differences in wealth alone can directly cause children to prefer wealthier groups. In Experiment 1, 4–5‐year‐old children developed a preference for a wealthy novel group over a less wealthy group. In Experiment 2, children did not develop preferences when groups differed by another kind of positive/negative attribute (i.e. living in brightly colored houses vs. drab houses), suggesting that wealth is a particularly meaningful group distinction. Lastly, in Experiment 3, the effect of favoring novel wealthy groups was moderated by group membership: Children assigned to a wealthy group showed ingroup favoritism, but those assigned to a less wealthy group did not. These experiments shed light on why children tend to be biased in favor of social groups that are higher in socioeconomic status.

This study explored the criteria that children and adults use when evaluating the niceness of a character who is distributing resources. Four‐ and five‐year‐olds played the ‘Giving Game’, in which two puppets with different amounts of chips each gave some portion of these chips to the children. Adults played an analogous task that mimicked the situations presented to children in the Giving Game. For all groups of participants, we manipulated the absolute amount and proportion of chips given away. We found that children and adults used different cues to establish which puppet was nicer: 4‐year‐olds focused exclusively on absolute amount, 5‐year‐olds showed some sensitivity to proportion, and adults focused exclusively on proportion. These results are discussed in light of their implications for equity theory and for theories of the development of social evaluation.

The present study analyzed the role of parents as potential sources of children's essentialist beliefs about ethnicity. We tested 76 parent–child (5‐year‐olds) dyads of Jewish Israeli parents from three social groups, defined by the kindergartens children attended: national religious, secular, or Jewish‐Arab integrated. We assessed parents' and children's beliefs, and parents' usage of ethnic attitudinal and categorization markers in a book‐reading activity. Overall, national religious parents manifested the strongest ethnic essentialism and endorsement of anti‐negotiations with Palestinians, and were the most likely to express negative attitudes and mark ethnic categories in their conversations with their children. Moreover, regression analyses revealed that ethnic categorization in parents' speech was the most reliable predictor of children's ethnic essentialism. Ethnic essentialism is transmitted to children not via explicit communication of intergroup beliefs or attitudes, but rather via the sheer marking of categories in ways that resonate with children's own intuitive ways of conceptualizing the social world.

During the first year of life, infants’ perception of speech becomes tuned to the phonology of the native language, as revealed in laboratory discrimination and categorization tasks using syllable stimuli. However, the implications of these results for the development of the early vocabulary remain controversial, with some results suggesting that infants retain only vague, sketchy phonological representations of words. Five experiments using a preferential listening procedure tested Dutch 11‐month‐olds’ responses to word, nonword and mispronounced‐word stimuli. Infants listened longer to words than nonwords, but did not exhibit this response when words were mispronounced at onset or at offset. In addition, infants preferred correct pronunciations to onset mispronunciations. The results suggest that infants’ encoding of familiar words includes substantial phonological detail.

The dimensional change card‐sorting task (DCCS task) is frequently used to assess young children's executive abilities. However, the source of children's difficulty with this task is still under debate. In the standard DCCS task, children have to sort, for example, test cards with a red cherry or a blue banana into two boxes marked with target cards showing a blue cherry and a red banana. Typically, 3‐year‐olds have severe problems switching from sorting by one dimension (e.g. color) to sorting by the other dimension (e.g. shape). Three experiments with 3‐ to 4‐year‐olds showed that separating the two dimensions as properties of a single object, and having them characterize two different objects (e.g. by displaying an outline of a cherry next to a red filled circle on the card) improves performance considerably. Results are discussed in relation to a number of alternative explanations for 3‐year‐olds’ difficulty with the DCCS task.

Early adversity, for example poor caregiving, can have profound effects on emotional development. Orphanage rearing, even in the best circumstances, lies outside of the bounds of a species‐typical caregiving environment. The long‐term effects of this early adversity on the neurobiological development associated with socio‐emotional behaviors are not well understood. Seventy‐eight children, who include those who have experienced orphanage care and a comparison group, were assessed. Magnetic resonance imaging (MRI) was used to measure volumes of whole brain and limbic structures (e.g. amygdala, hippocampus). Emotion regulation was assessed with an emotional go‐nogo paradigm, and anxiety and internalizing behaviors were assessed using the Screen for Child Anxiety Related Emotional Disorders, the Child Behavior Checklist, and a structured clinical interview. Late adoption was associated with larger corrected amygdala volumes, poorer emotion regulation, and increased anxiety. Although more than 50% of the children who experienced orphanage rearing met criteria for a psychiatric disorder, with a third having an anxiety disorder, the group differences observed in amygdala volume were not driven by the presence of an anxiety disorder. The findings are consistent with previous reports describing negative effects of prolonged orphanage care on emotional behavior and with animal models that show long‐term changes in the amygdala and emotional behavior following early postnatal stress. These changes in limbic circuitry may underlie residual emotional and social problems experienced by children who have been internationally adopted.

While there is evidence for an association between the development of reading and arithmetic, the precise locus of this relationship remains to be determined. Findings from cognitive neuroscience research that point to shared neural correlates for phonological processing and arithmetic as well as recent behavioral evidence led to the present hypothesis that there exists a highly specific association between phonological awareness and single‐digit arithmetic with relatively small problem sizes. The present study examined this association in 37 typically developing fourth and fifth grade children. Regression analyses revealed that phonological awareness was specifically and uniquely related to arithmetic problems with a small but not large problem size. Further analysis indicated that problems with a high probability of being solved by retrieval, but not those typically associated with procedural problem‐solving strategies, are correlated with phonological awareness. The specific association between phonological awareness and arithmetic problems with a small problem size and those for which a retrieval strategy is most common was maintained even after controlling for general reading ability and phonological short‐term memory. The present findings indicate that the quality of children’s long‐term phonological representations mediates individual differences in single‐digit arithmetic, suggesting that more distinct long‐term phonological representations are related to more efficient arithmetic fact retrieval.