Team-based physical activity (PA) can improve social cognition; however, few studies have investigated the neurobiological mechanism underlying this benefit. Accordingly, a hyper-scanning protocol aimed to determine whether the interbrain synchrony (IBS) is influenced by an acute bout of team-based PA (i.e., tandem rope skipping). Specifically, we had socially avoidant participants (SOA, N=15 dyads) and their age-matched controls (CO, N=16 dyads) performed a computer-based cooperative task while EEG was recorded before and after two different experimental conditions (i.e., 30-min of team-based PA versus sitting). Phase locking value (PLV) was used to measure IBS. Results showed improved frontal gamma band IBS after the team-based PA compared to sitting when participants received successful feedback in the task (Mskipping = 0.016, Msittting = -0.009, p = 0.082, ηp2 = 0.387). The CO group showed a larger change in frontal and central gamma band IBS when provided failure feedback in the task (Mskipping = 0.017, Msittting = -0.009, p = 0.075, ηp2 = 0.313). Thus, results suggest that socially avoidant individuals may benefit from team-based PA via improved interbrain synchrony. Moreover, our findings deepen our understanding of the neurobiological mechanism by which team-based PA may improve social cognition among individuals with or without social avoidance.

Emotions are fundamental to social interaction and deeply intertwined with interpersonal dynamics, especially in romantic relationships. Although the neural basis of interaction processes in romance has been widely explored, the underlying emotions and the connection between relationship quality and neural synchronization remain less understood. Our study employed EEG hyperscanning during a non-interactive video-watching paradigm to compare the emotional coordination between romantic couples and close friends. Couples showed significantly greater behavioral and prefrontal alpha synchronization than friends. Notably, couples with low relationship quality required heightened neural synchronization to maintain robust behavioral synchronization. Further support vector machine analysis underscores the crucial role of prefrontal activity in differentiating couples from friends. In summary, our research addresses gaps concerning how intrinsic emotions linked to relationship quality influence neural and behavioral synchronization by investigating a natural non-interactive context, thereby advancing our understanding of the neural mechanisms underlying emotional coordination in romantic relationships.

BACKGROUND: This study examines the extent to which depressive symptoms mediate the link between childhood friendship (CF) and physical function among middle-aged and older adults in China.
METHODS: China Health and Retirement Longitudinal Study (CHARLS) data were used; specifically, CHARLS life history survey (conducted from June 1-December 31, 2014) and follow-up health survey (conducted from July 1-September 30, 2015) data were used. The Sobel test, Bootstrap test and multivariable logistic regression were performed to examine the mediating role of depressive symptoms (measured by the 10-item Center for Epidemiologic Studies Depression Scale) in the association between CF (measured by a standardized retrospective questionnaire) and physical function, which was measured by basic activities of daily living (BADL) disability, instrumental activities of daily living (IADL) disability, and grip strength.
RESULTS: A total of 12,170 participants aged 45 years or older were included in this cross-sectional study. After controlling for covariates, low-quality CF was associated with an increased prevalence of BADL disability (OR = 1.18; 95 % CI = 1.05-1.32), IADL disability (OR = 1.25; 95 % CI = 1.12-1.40), and low grip strength (OR = 1.21; 95 % CI = 1.09-1.34). The proportion of the mediating effect of depressive symptoms was 48 % for CF and BADL, 40 % for CF and IADL, and 11 % for CF and grip strength. Depressive symptoms and worse CF have a joint effect on BADL disability (OR = 3.30; 95 % CI = 2.82-3.85), IADL disability (OR = 3.52; 95 % CI = 3.03-4.09), and low grip strength (OR = 1.65; 95 % CI = 1.43-1.92).
CONCLUSIONS: Not all potential confounding factors (such as childhood behavioural problems, genetic factors, and memory function) were measured in the analysis, and there may have been recall bias in the retrospective collection of CF data.
CONCLUSIONS: Individuals with high-quality CF were more likely to have a decreased prevalence of impaired physical function in later life. Depressive symptoms acted as a mediator associated with the development of CF.

OBJECTIVE: This study investigated the association between internet use and loneliness among older Chinese adults, and the mediating effects of family support, friend support, and social participation. These associations were evaluated in the context of urban and non-urban geographic settings.
METHODS: This study used data from the 2018 wave of the China Longitudinal Ageing Social Survey (N = 10,126), examining samples of urban (n = 3,917) and non-urban (n = 6,209) older adults separately. Linear regression and path analysis within a structural equation modeling framework were employed.
RESULTS: Internet use was negatively associated with loneliness for both urban and non-urban residing older adults. Family support and social participation mediated the association between internet use and loneliness for both urban and non-urban residing older Chinese adults, but friend support mediated this association only for urban older residents.
CONCLUSIONS: This study shed light on our understanding of the relationship between internet use and loneliness among older adults in the Chinese context. Also, these findings suggested that digital interventions for loneliness should pay special attention to the different characteristics of urban and non-urban dwelling older Chinese adults.

BACKGROUND: Suicide is a significant global public health concern. However, previous studies have predominantly focused on individual-level risk factors. Against this backdrop, microsystem suicide propinquity, which encompasses suicidal thoughts and behaviors (STB) within families and peer groups, is significant in elucidating the development and perpetuation of STB in adolescents.
METHODS: This study utilized data from the National Longitudinal Study of Adolescent to Adult Health (Add Health, 1994-2018). Adolescents who reported instances of suicide attempts among their friends and family members during Wave 1 were selected (N = 4826). Generalized estimation equations (GEE) and structural equation models (SEM) were employed.
RESULTS: GEE analyses indicated that individuals with friends who had attempted suicide exhibited higher risks for suicidal ideation (OR [95 % CI] = 2.57 [2.13, 3.11]) and suicide attempts (OR [95 % CI] = 2.47 [1.78, 3.42]). Also, individuals with family members who had attempted suicide exhibited higher risks for suicidal ideation (OR [95 % CI] = 2.37 [1.62, 3.46]) and attempts (OR [95 % CI] = 2.27 [1.17, 4.41]). However, friends\' and family members\' suicide attempts failed to show significant interactive effect. Besides, SEM analyses indicated that friends\' and family members\' suicide attempts were associated with one\'s long-term suicidal ideation and attempts via depressive symptoms.
CONCLUSIONS: Suicide attempts of friends and family during adolescence were long-term risk factors for suicidal ideation and attempts from adolescence to young adulthood. Moreover, depressive symptoms served as long-term mechanisms in these associations.

COVID-19 vaccine hesitancy remains problematic among healthcare workers. Social network influences may shape vaccine decision-making, but few studies have examined this in this critical workforce. We assessed the relationship between friends\' COVID-19 vaccination attitudes and personal hesitancy among Chinese healthcare personnel. In December 2022-January 2023, a cross-sectional online survey was conducted at a tertiary hospital in China using WeChat. Of the 1832 healthcare personnel who were invited to answer the structured questionnaire, 613 (33.5%) samples had valid data for data analysis. Logistic regression examined the association between friends\' hesitancy and participants\' own hesitancy, adjusting for confounders. Of 613 healthcare workers included, 266 (43.4%) were hesitant. Those with hesitant friends had 6.34 times higher adjusted odds of hesitating themselves versus those without hesitant friends (95% CI 2.97-13.52). Strong associations persisted across subgroups. Chinese healthcare workers\' COVID-19 vaccination hesitancy was highly influenced by perceived friends\' attitudes. Fostering pro-vaccine social norms through trusted peer networks could help promote vaccine acceptance in this critical workforce.

Cooperation is widespread and arguably a pivotal evolutionary force in maintaining animal societies. Yet, proximately, what underlying motivators drive individuals to cooperate remains relatively unclear. Since \'free-riders\' can exploit the benefits by cheating, selecting the right partner is paramount. Such decision rules need not be based on complex calculations and can be driven by cognitively less-demanding mechanisms, like social relationships (e.g. kinship, non-kin friendships, dyadic tolerance), social status (e.g. dominance hierarchies) and personalities (social and non-social traits); however, holistic evidence related to those mechanisms is scarce. Using the classical \'loose-string paradigm\', we tested cooperative tendencies of a hierarchical primate, the long-tailed macaque (Macaca fascicularis). We studied three groups (n = 21) in their social settings, allowing partner choice. We supplemented cooperation with observational and experimental data on social relationships, dominance hierarchies and personality. Friendship and dissimilarities in non-social \'exploration\' and \'activity-sociability\' personality traits predicted the likelihood of cooperative dyad formation. Furthermore, the magnitude of cooperative success was positively associated with friendship, low rank-distance and dissimilarity in the activity-sociability trait. Kinship did not affect cooperation. While some findings align with prior studies, the evidence of (non-social) personality heterophily promoting cooperation may deepen our understanding of the proximate mechanisms and, broadly, the evolution of cooperation.

BACKGROUND: Childhood maltreatment is a common problem that can have lasting effects on the physical and mental health of adolescents who have experienced it, including sleep quality.
OBJECTIVE: This study will investigate the relationship between childhood maltreatment and sleep quality in adolescents using a weekly diary method.
METHODS: In this study, students from a middle school in central China were recruited as research subjects, and a total of 11 classes with 470 students were investigated.
METHODS: In order to fill in the gaps of previous studies, a weekly diary method was used to collect data. Subjects were required to complete three scales once a week for seven consecutive weeks, including the Childhood Trauma Questionnaire (CTQ), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Pittsburgh Sleep Quality Index scale (PSQI).
RESULTS: Findings suggest that childhood maltreatment has a negative impact on adolescent\'s sleep quality at the weekly level (γ01c = -0.07, t = -5.71, p < .001) . The negative effect of childhood maltreatment on sleep quality was significantly reduced with the addition of perceived social support (γ01c\' = -0.03, t = -2.83, p < .01). Notably, support from friends (γ01a*γ02b = -0.01) and significant others (γ01a*γ02b = -0.02) also played an important mediating role in child maltreatment and adolescent sleep quality, but family support remained the most important support in adolescents (γ01a*γ02b = -0.04).
CONCLUSIONS: The present study has confirmed the negative correlation between childhood maltreatment and sleep quality in adolescents. Furthermore, it has clarified the mechanism of perceived social support and the separate mediating roles of perceived family support, perceived friend support, and perceived significant other support.

Little is known about whether and why social networks protect mental health among informal caregivers. This study examined the association between informal caregiver social network types and depressive symptoms and the mediatory mechanism of psychological resilience. Latent class analysis, applied to cross-sectional data on 278 Singaporean caregivers, identified four social network types: restricted (42%), friend (16%), family (21%), and diverse (21%). Path analysis showed that the diverse social network type, compared to the restricted social network type, was associated with a lower level of depressive symptoms, and psychological resilience fully mediated this association. Interventions should help caregivers to maintain social networks with their family and friends.
Informal caregiver social network typologies were explored using data from Singapore.Diverse, friend, family, and restricted social network types were identified.Diverse social network type was negatively associated with depressive symptoms.Psychological resilience fully mediated the association.

The relationship between social support and mortality, especially cardio-cerebrovascular mortality, still has some limitations in the assessment of social support, sample selection bias, and short follow-up time. We used the data from 2005 to 2008 National Health and Nutrition Examination Survey to examine this relationship. The study analyzed a total of 6776 participants, divided into Group 1, Group 2, and Group 3 according to the social support score (0-1; 2-3; 4-5). Multivariable adjusted COX regression analyses of our study showed that Group 3 and Group 2 had a reduced risk of all-cause and cardio-cerebrovascular mortality (Group 3 vs 1, HR: 0.55, P < 0.001; HR: 0.4, P < 0.001; Group 2 vs 1, HR: 0.77, P = 0.017; HR: 0.58, P = 0.014) compared with Group 1. The same results were observed after excluding those who died in a relatively short time. Additionally, having more close friends, being married or living as married, and enough attending religious services were significantly related to a lower risk of mortality after adjustment. In brief, adequate social support is beneficial in reducing the risk of all-cause mortality and cardio-cerebrovascular mortality in middle-aged and older adults, especially in terms of attending religious services frequency, the number of close friends, and marital status.