The sense of belonging reduces ingroup favoritism in children.

Belonging is an important motive for intergroup behavior. Adults display pronounced ingroup favoritism when the sense of inclusion by an ingroup is decreased or threatened. The present study investigated whether ingroup belonging reduces ingroup favoritism in 6-year-old children in terms of costly sharing. Children were allocated to a novel group in a minimal-group paradigm. In two conditions, children played a brief ball-tossing game and were either included (ingroup-inclusion condition) or excluded (ingroup-exclusion condition) by their ingroup members. Children in a no-interaction condition did not have any interactions with the members of the ingroup. After this manipulation, we tested the extent to which children shared resources with ingroup and outgroup members. We found that children in the ingroup-exclusion and no-interaction conditions shared more resources with their ingroup member than their outgroup member, while children in the ingroup-inclusion condition shared equally with the ingroup and outgroup members. These results could inform interventions aimed at fostering positive intergroup relations.

What did COVID-19 Change? The Impact of COVID-19 on Korean Parents' and Children's Daily Lives and Stress.

The COVID-19 outbreak has not only posed a threat to physical health but has also changed our daily lives. This study explored how the COVID-19 pandemic affected Korean parents' and children's daily lives and stress levels. Parents' childcare time, children's screen time, the time spent for social interactions and learning, and parents' and children's stress levels before and after the pandemic were compared. The main caregivers' childcare time increased significantly during the pandemic (4.00 h/day). For children, the time spent for screen time (1.76 h) and online interactions (0.95 h) increased significantly, whereas face-to-face interaction time (4.17 h) and time spent learning (2.16 h) decreased significantly. In addition, parents' and children's stress levels increased significantly during the pandemic. Other descriptive information is provided and discussed. Our results indicate that Korean parents and children experienced significant disruption to their daily lives and increased stress during the pandemic.

Influence of Additive Firing on the Surface Characteristics, Streptococcus mutans Viability and Optical Properties of Zirconia.

The purpose of this study was to observe whether the repetitive firing of dental zirconia caused changes in surface characteristics, S. mutans viability, and optical properties of zirconia. Dental zirconia blocks were sintered and randomly distributed into seven experimental groups: F0-F6. Except for F0, which only went through sintering, the additive firing was performed in order for F1-F6. Surface roughness, contact angle, S. mutans viability by fluorescence, and translucency parameter were measured. They were all highest after sintering (F0) and decreased after additive firings (F1-F6). The additive firing of zirconia after sintering decreased surface roughness, contact angle, S. mutans viability, and translucency. The number of firings after the first firing was not found to be critical in surface characteristics, S. mutans viability, and optical property. Changes in surface characteristics might have led to a decrease in S. mutans viability, while the change of translucency was not clinically significant. This implies that additive firing may prevent secondary caries under zirconia restorations, not compromising esthetic appearance.