Teenagers' but not young adults' beliefs about intrinsic interpersonal obligations for group members

Previous research has indicated that children perceive social category members as having intrinsic obligations toward each other, which shape their expectations for social interactions. However, it is unclear whether teenagers (aged 13 to 15) and young adults (aged 19 to 21) continue to hold such beliefs, given their increased experience with group dynamics and external social rules. To explore this question, three experiments were conducted with a total of 360 participants (N = 180 for each age group). Experiment 1 examined negative social interactions using different methods in two sub-experiments, while Experiment 2 focused on positive social interactions to examine whether participants viewed social category members as intrinsically obligated to avoid harming each other and to offer assistance. Results revealed that teenagers evaluated within-group harm and non-help as unacceptable, regardless of external rules, whereas they viewed between-group harm and non-help as both acceptable and unacceptable, depending on the presence of external rules. Conversely, young adults considered both within-group and between-group harm/non-help as more acceptable if an external rule permitted such behavior. These findings suggest that teenagers believe that members of a social category are intrinsically obligated to help and not harm each other, whereas young adults believe that individual social interactions are constrained mainly by external rules. That is, teenagers hold stronger beliefs than young adults about intrinsic interpersonal obligations to group members. Thus, in-group moral obligations and external rules contribute differently to the evaluation and interpretation of social interactions at different developmental stages.

Identifying the social context of single- and mixed-species group formation in large African herbivores

Despite continued interest in mixed-species groups, we still lack a unified understanding of how ecological and social processes work across scales to influence group formation. Recent work has revealed ecological correlates of mixed-species group formation, but the mechanisms by which concomitant social dynamics produce these patterns, if at all, is unknown. Here, we use camera trap data for six mammalian grazer species in Serengeti National Park. Building on previous work, we found that ecological variables, and especially forage quality, influenced the chances of species overlap over small spatio-temporal scales (i.e. on the scales of several metres and hours). Migratory species (gazelle, wildebeest and zebra) were more likely to have heterospecific partners available in sites with higher forage quality, but the opposite was true for resident species (buffalo, hartebeest and topi). These findings illuminate the circumstances under which mixed-species group formation is even possible. Next, we found that greater heterospecific availability was associated with an increased probability of mixed-species group formation in gazelle, hartebeest, wildebeest and zebra, but ecological variables did not further shape these patterns. Overall, our results are consistent with a model whereby ecological and social drivers of group formation are species-specific and operate on different spatio-temporal scales. This article is part of the theme issue 'Mixed-species groups and aggregations: shaping ecological and behavioural patterns and processes'.

The Geography of Mental Health, Urbanicity, and Affluence

Residential location has been shown to significantly impact mental health, with individuals in rural communities experiencing poorer mental health compared to those in urban areas. However, the influence of an individual's social group on the relationship between residential location and mental health outcomes remains unclear. This study disaggregates the rural-urban binary and investigates how geography and social groupings interact to shape mental health outcomes. Merging data from PLACES and Claritas PRIZM, we conducted a hotspot analysis, generated bivariate choropleth maps, and applied multiscale geographically weighted regressions to examine the spatial distribution of mental health and social groupings. Our findings reveal that mental health is influenced by complex interactions, with social groups playing a critical role. Our study highlights that not all rural and urban areas are alike, and the extent to which social groups influence mental health outcomes varies within and across these areas. These results underscore the need for policies that are tailored to meet the unique mental health needs of individuals from different social groups in specific geographic locations to inform policy interventions that more effectively address mental health disparities across diverse communities.

Rise and fall of the (social) group

This article maps the rise and fall of the idea of a (social) group across medicine in the context of contemporary analyses in psychology and sociology. This history shows the early 20th century emergence and growth of group medicine, group therapy and group comparisons. In recent decades, however, the idea that groups constituted the basic units of society has been replaced with the emergence of populations and systems that offer a more virtual and abstract context for individual relationships. This has implications for explanation itself as the demise of groups has changed the epistemological ground-rules for understanding identity formation and social change.

Singing for Wellbeing: Formulating a Model for Community Group Singing Interventions

Research into the benefits of community-based group singing, pertaining to positive wellbeing and Quality of Life is lacking. Additionally, no preferred theoretical framework exists for community singing-based interventions. For the present study, six members of a UK community choir were interviewed using a semi-structured interview approach. Interpretative phenomenological analysis (IPA) was employed. Analysis produced superordinate themes of: Social Factors with key elements such as social bonds and group identity; Psychological Factors, highlighting self-efficacy, self-identity and positive emotions and Psychological Motivations for Joining the Group, including autonomy, change of life circumstance and seeking a new challenge. The style/method of the group, teaching, music and group leader, were shown to have an influence on perceived benefits of the singing group. A key product of this study beyond the evidenced benefits of group singing is the development of an intervention model that optimises wellbeing outcomes in community singing groups underpinned by psychological theory, findings from the wider literature and the results of this study.

Children's thinking about group-based social hierarchies

Wealth, power, and status are distributed unevenly across social groups. A surge of recent research reveals that people being recognizing, representing, and reasoning about group-based patterns of inequity during the first years of life. We first synthesize recent research on what children learn about group-based social hierarchies as well as how this learning occurs. We then discuss how children not only learn about societal structures but become active participants in them. Studying the origins and development of children's thoughts and behavior regarding group-based social hierarchies provides valuable insight into how systems of inequity are perpetuated across generations and how intergroup biases related to wealth, power, and status may be mitigated and reshaped early in development.

Impaired processing of conspecifics in Parkinson's disease

Experimental evidence indicates that the inferior frontal gyrus (IFG) processes emotional/affective features crucial to elaborate knowledge about social groups and that knowledge of social concepts is stored in the anterior temporal lobe (ATL).We investigated whether knowledge about social groups is impaired in Parkinson's disease (PD), in which dysfunctional connectivity between IFG and ATL has been demonstrated.PD patients (N = 20) and healthy controls (HC, N = 16) were given a lexical decision task in a semantic priming paradigm: the prime-targets included 144 words and 144 pseudowords, each preceded by three types of prime ("animals," "things," "persons"). Out of these 288 prime-targets, forty-eight were congruent (same category) and 96 incongruent (different category). Out of 48 congruent prime-targets, 24 denoted social items and 24 nonsocial items. Thus, four types of trials were obtained: congruent social; congruent nonsocial; incongruent social; incongruent nonsocial.Congruent target-words were recognized better than incongruent target-words by all groups. The semantic priming effect was preserved in PD; however, accuracy was significantly lower in PD than in HC in social items. No difference emerged between the two groups in nonsocial items.Impaired processing of words denoting social groups in PD may be due to impairment in accessing the affective/emotional features that characterize conceptual knowledge of social groups, for the functional disconnection between the IFG and the ATL.

Personality Traits Predict Social Network Size in Older Adults

Humans live in unusually large groups, where relationships are thought to be maintained through complex socio-communicative abilities. The size and quality of social networks are associated with health and well-being outcomes throughout life. However, how some individuals manage to form larger social networks is not well understood. If socio-communicative traits evolved to form and maintain relationships, personality traits should be associated with variation in network size. Here, using the English Longitudinal Study of Ageing (ELSA), we investigate the impact of extraversion, agreeableness, and verbal communication on network size (N = 5,202) and network size change over time (N = 1,511) in later life for kin and friend networks. Higher levels of extraversion and agreeableness were associated with greater social network sizes but did not predict network size change over 14 years. The findings are discussed considering the evolutionary hypothesis that communicative and affiliative traits may have evolved to support the maintenance of social networks.

Greenhouse Gas Emissions Associated With the Mexican Diet: Identifying Social Groups With the Largest Carbon Footprint

Background

Most studies of the climate footprint of diets have been conducted in countries in the global north, but the majority of the world population lives in global south countries. We estimated total dietary greenhouse gas emissions (GHGE) in Mexico, examined the contribution of major food and beverage groups, and assessed variation across social groups.

Methods

We linked individual-level dietary data from the Mexican National Health and Nutrition Survey 2018 to the SHARP Indicators Database, containing GHGE estimates for 182 primary food and beverages.

Results

Mean dietary GHGE was 3.9 kg of carbon dioxide equivalent per person per day. Dietary GHGE is highest among those in young adulthood and middle age versus adolescents and older adults, and among males, those with higher educational attainment, higher socioeconomic status, that do not speak an indigenous language, and that live in urban areas.

Conclusion

The Mexican diet has a much lower carbon footprint than diets in other Latin American countries for which such estimates are available. In contrast to patterns observed in Argentina and Brazil, dietary GHGE was lowest in those in lower socioeconomic and educational strata and in rural areas. A better understanding of the differences in diet sustainability between and within countries will be needed for developing global and local strategies that meet the environmental sustainability goals.

Changes in 25-hydroxyvitamin D levels post-vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID-19 pandemic: A systematic review

BACKGROUND

People of Black and Asian ethnicities have a higher infection rate and mortality as a result of COVID-19. It has also been reported that vitamin D deficiency may play a role in this, possibly because of the multi-gene regulatory function of the vitamin D receptor. As a result, increased dietary intake and/or supplementation to attain adequate 25-hydroxyvitamin D (25(OH)D) levels could benefit people in these ethnicities. The present study aimed to review the literature examining the changes in 25(OH)D in different types of vitamin D supplementation from randomised controlled trials in this population.

METHODS

This systematic review was conducted using the PRISMA guidelines. Electronic databases were systematically searched using keywords related to vitamin D supplementation in Black and Asian ethnicities.

RESULTS

Eight studies were included in the review. All the included studies found that supplementation of vitamin D (D₂ and D₃ ), regardless of dosage, increased 25(OH)D levels compared to a placebo. All trials in which participants were vitamin D deficient at baseline showed increased 25(OH)D levels to a level considered adequate. Two studies that used food fortification yielded smaller 25(OH)D increases compared to similar studies that used oral supplementation (10.2 vs. 25.5 nmol L^-1 , respectively). Furthermore, vitamin D₂ supplementation yielded significantly lower 25(OH)D increases than vitamin D₃ supplementation.

CONCLUSIONS

Oral vitamin D supplementation may be more efficacious in increasing 25(OH)D levels than food fortification of Black and Asian ethnicities, with vitamin D₃ supplementation possibly being more efficacious than vitamin D₂ . It is recommended that people with darker skin supplement their diet with vitamin D₃ through oral tablet modes where possible, with recent literature suggesting a daily intake of 7000-10,000 IU to be potentially protective from unfavourable COVID-19 outcomes. As a result of the paucity of studies, these findings should be treated as exploratory.

A metapopulation model of social group dynamics and disease applied to Yellowstone wolves

The population structure of social species has important consequences for both their demography and transmission of their pathogens. We develop a metapopulation model that tracks two key components of a species' social system: average group size and number of groups within a population. While the model is general, we parameterize it to mimic the dynamics of the Yellowstone wolf population and two associated pathogens: sarcoptic mange and canine distemper. In the initial absence of disease, we show that group size is mainly determined by the birth and death rates and the rates at which groups fission to form new groups. The total number of groups is determined by rates of fission and fusion, as well as environmental resources and rates of intergroup aggression. Incorporating pathogens into the models reduces the size of the host population, predominantly by reducing the number of social groups. Average group size responds in more subtle ways: infected groups decrease in size, but uninfected groups may increase when disease reduces the number of groups and thereby reduces intraspecific aggression. Our modeling approach allows for easy calculation of prevalence at multiple scales (within group, across groups, and population level), illustrating that aggregate population-level prevalence can be misleading for group-living species. The model structure is general, can be applied to other social species, and allows for a dynamic assessment of how pathogens can affect social structure and vice versa.

Tests of hypotheses for group formation in the subtropical leaf-dwelling bat, Kerivoula furva

Investigating factors that promote group living in animals can help us to understand the evolution of sociality. The dark woolly bat, Kerivoula furva, forms small groups and uses furled leaves of banana (Musa formosana) as day roosts in subtropical Taiwan. In this study, we reported on the roosting ecology and social organization of K. furva. We examined whether ecological constraints, demographic traits, and physiological demands contributed to its sociality. From July 2014 to May 2016, we investigated the daily roost occupation rate, group size, and composition of each roost, and we calculated association indices in pairs. The results showed K. furva lived in groups throughout the year, and the average daily roost occupation rate was approximately 6.7% of all furled leaves that were suitable for roosting. The size of roosting groups of adults in each roost varied between 1 and 13; group size was independent of air temperature during both reproductive and nonreproductive seasons. The vast majority of roosting groups was composed of females and their young, and males frequently roosted solitarily or in a bachelor group. Forty adult bats were captured ≥4 times during the study period. The association indices in pairs of these 40 bats ranged between 0 and 0.83 with an average of 0.05 ± 0.14 (n = 780). The average association index of female-female pairs was significantly higher than that of female-male pairs and male-male pairs. Based on the association indices, the 40 bats were divided into seven social groups with social group sizes that varied between 2 and 10. Despite changing day roosts frequently, the relatively stable social bonds were maintained year-round. Our results that groups of K. furva were formed by active aggregation of multiple generation members supported the demographic traits hypothesis.

Reframing social categorization as latent structure learning for understanding political behaviour

Affiliating with political parties, voting and building coalitions all contribute to the functioning of our political systems. One core component of this is social categorization-being able to recognize others as fellow in-group members or members of the out-group. Without this capacity, we would be unable to coordinate with in-group members or avoid out-group members. Past research in social psychology and cognitive neuroscience examining social categorization has suggested that one way to identify in-group members may be to directly compute the similarity between oneself and the target (dyadic similarity). This model, however, does not account for the fact that the group membership brought to bear is context-dependent. This review argues that a more comprehensive understanding of how we build representations of social categories (and the subsequent impact on our behaviours) must first expand our conceptualization of social categorization beyond simple dyadic similarity. Furthermore, a generalizable account of social categorization must also provide domain-general, quantitative predictions for us to test hypotheses about social categorization. Here, we introduce an alternative model-one in which we infer latent groups of people through latent structure learning. We examine experimental evidence for this account and discuss potential implications for understanding the political mind. This article is part of the theme issue 'The political brain: neurocognitive and computational mechanisms'.

Kin relationships in cultural species of the marine realm: case study of a matrilineal social group of sperm whales off Mauritius island, Indian Ocean

Understanding the organization and dynamics of social groups of marine mammals through the study of kin relationships is particularly challenging. Here, we studied a stable social group of sperm whales off Mauritius, using underwater observations, individual-specific identification, non-invasive sampling and genetic analyses based on mitochondrial sequencing and microsatellite profiling. Twenty-four sperm whales were sampled between 2017 and 2019. All individuals except one adult female shared the same mitochondrial DNA (mtDNA) haplotype-one that is rare in the western Indian Ocean-thus confirming with near certainty the matrilineality of the group. All probable first- and second-degree kin relationships were depicted in the sperm whale social group: 13 first-degree and 27 second-degree relationships were identified. Notably, we highlight the likely case of an unrelated female having been integrated into a social unit, in that she presented a distinct mtDNA haplotype and no close relationships with any members of the group. Investigating the possible matrilineality of sperm whale cultural units (i.e. vocal clans) is the next step in our research programme to elucidate and better apprehend the complex organization of sperm whale social groups.

The Unintended Consequences of the Things We Say: What Generic Statements Communicate to Children About Unmentioned Categories

Adults frequently use generic language (e.g., "Boys play sports") to communicate information about social groups to children. Whereas previous research speaks to how children often interpret information about the groups described by generic statements, less is known about what generic claims may implicitly communicate about unmentioned groups (e.g., the possibility that "Boys play sports" implies that girls do not). Study 1 (287 four- to six-year-olds, 56 adults) and Study 2 (84 four- to six-year-olds) found that children as young as 4.5 years draw inferences about unmentioned categories from generic claims (but not matched specific statements)-and that the tendency to make these inferences strengthens with age. Study 3 (181 four- to seven-year-olds, 65 adults) provides evidence that pragmatic reasoning serves as a mechanism underlying these inferences. We conclude by discussing the role that generic language may play in inadvertently communicating social stereotypes to young children.

Language as a Social Cue

Social groups are a pervasive feature of human life. One factor that is often understudied in the literature on person perception and social categorization is language. Yet, someone's language (and accent) provides a tremendous amount of social information to a listener. Disciplines across the social and behavioral sciences-ranging from linguistics to anthropology to economics-have exposed the social significance of language. Less social psychological research has historically focused on language as a vehicle for social grouping. Yet, new approaches in psychology are reversing this trend. This article first reviews evidence, primarily from psycholinguistics, documenting how speech provides social information. Next it turns to developmental psychology, showing how young humans begin to see others' language as conveying social group information. It then explores how the tendency to see language as a social cue has vast implications for people's psychological processes (e.g., psychological essentialism and trust) and also for society, including education and the law.

Understanding Temporal Social Dynamics in Zoo Animal Management: An Elephant Case Study

Zoo animal management procedures which lead to changes to social groups can cause disruption in social hierarchies and the temporary breakdown of social relationships. Animals have different roles in social networks. Understanding individual positions in social networks is important for effective management and ensuring positive welfare for all animals. Using elephants as a case study, the aim of this research was to investigate temporal social dynamics in zoo animals. Behavioural data were collected between January 2016 and February 2017 from 10 African and 22 Asian elephants housed at seven zoos and safari parks in the UK and Ireland. Social interactions were defined as positive physical, positive non-physical, negative physical or negative non-physical. Social network analysis explored social relationships including the fluidity of networks over time and dyadic reciprocity. Social interaction networks were found to be fluid but did not follow a seasonal pattern. Positive interaction networks tended to include the entire social group whereas negative interactions were restricted to specific individuals. Unbalanced ties were observed within dyads, suggesting potential inequalities in relationships. This could impact on individual experiences and welfare. This research highlights subtle temporal dynamics in zoo elephants with the potential for species-level differences. Similar temporal dynamics may also be present in other socially housed zoo species. This research thus provides evidence for the importance of understanding the social networks of zoo animals over longer periods of time. Understanding social networks enables pro-active and evidence-based management approaches. Further research should seek to identify the minimum sampling efforts for social networks in a range of species, to enable the implementation of regular monitoring of social networks and thus improve the welfare of social species under human care.

Child maltreatment is linked to difficulties in identifying with social groups as a young adult

Subjective feelings of disconnectedness from social groups have been found to be detrimental to mental health. However, little is known about the factors determining people's ability to attach to groups. We contend that child maltreatment will impair people's ability to group identification across the lifespan, and present a cross-sectional study involving 396 young adults from Spain, aimed at testing this hypothesis. Results reveal that, as expected, a greater degree of maltreatment received before the age of 14 is linked to a lower number of social groups one identifies with, even after controlling for current levels of depression, anxiety, and borderline personality. Statement of contribution What is already known on this subject? Experiencing a subjective sense of identification with groups promotes well-being and psychological adjustment. Subjective feelings of disconnectedness from social groups are detrimental to mental health. What does this study add? Little is known about the factors determining people's ability to identify with groups. Child maltreatment is analysed as an important distal determinant of this ability. Child maltreatment thwarts people's ability to develop a sense of belonging to social groups. A greater degree of maltreatment received before the age of 14 is linked to a lower number of social groups young adults identifies with, after controlling for core mental health dimensions.

Understanding the Sociocognitive Process of Construction Workers' Unsafe Behaviors: An Agent-Based Modeling Approach

Previous literature has recognized that workers’ unsafe behavior is the combined result of both isolated individual cognitive processes and their interaction with others. Based on the consideration of both individual cognitive factors and social organizational factors, this paper aims to develop an Agent-Based Modeling (ABM) approach to explore construction workers’ sociocognitive processes under the interaction with managers, coworkers, and foremen. The developed model is applied to explore the causes of cognitive failure of construction workers and the influence of social groups and social organizational factors on the workers’ unsafe behavior. The results indicate that (1) workers’ unsafe behaviors are gradually reduced with the interaction with managers, foremen, and workers; (2) the foreman is most influential in reducing workers’ unsafe behaviors, and their demonstration role can hardly be ignored; (3) the failure of sociocognitive process of construction workers is affected by many factors, and cognitive process errors could be corrected under social norms; and (4) among various social organizational factors, social identity has the most obvious effect on reducing workers’ unsafe behaviors, and preventive measures are more effective than reactive measures in reducing workers’ unsafe behaviors.

Social structure learning in human anterior insula

Humans form social coalitions in every society, yet we know little about how we learn and represent social group boundaries. Here we derive predictions from a computational model of latent structure learning to move beyond explicit category labels and interpersonal, or dyadic, similarity as the sole inputs to social group representations. Using a model-based analysis of functional neuroimaging data, we find that separate areas correlate with dyadic similarity and latent structure learning. Trial-by-trial estimates of ‘allyship’ based on dyadic similarity between participants and each agent recruited medial prefrontal cortex/pregenual anterior cingulate (pgACC). Latent social group structure-based allyship estimates, in contrast, recruited right anterior insula (rAI). Variability in the brain signal from rAI improved prediction of variability in ally-choice behavior, whereas variability from the pgACC did not. These results provide novel insights into the psychological and neural mechanisms by which people learn to distinguish ‘us’ from ‘them.’

In every society, people form social coalitions — we draw boundaries between 'us' and 'them'. But how do we decide who is one of 'us' and who is one of 'them'? One way is to use arbitrary categories. For example, we say that those living 49 degrees north of the Earth’s equator are Canadian, whereas those living south of it are American. Another possibility is to use physical characteristics. But what about when neither of these options are available?

By monitoring brain activity in healthy volunteers learning about other people’s political values, Lau et al. obtained insights into how people make these decisions. Participants lying in a brain scanner were asked to report their position on a political issue. They then learned the positions of three other hypothetical participants – A, B and C – on the same issue. After repeating this procedure for eight different issues, the volunteers had to decide whether they would align with A or with B on a 'mystery' political issue.

So how do participants choose between A and B? One possibility is that they simply choose whichever one has views most similar to their own. If this is the case, the views of hypothetical person C should not affect their decision. But in practice, C's views – specifically how much they resemble the volunteer's own – do influence whether the volunteer chooses A or B. This suggests that we choose our allies based on more than just their similarity to ourselves.

Using a mathematical model, Lau et al. show that volunteers also take into account how similar the views of the other ‘participants’ are to each other. In other words, they consider the structure of the social group as a whole. Moreover, the results from brain imaging show that different regions of the brain are active when volunteers track the structure of the entire group, as opposed to their own similarity with each individual.

Notably though, the activity of the group-tracking region explains people's alignment choices better than the activity of the similarity-tracking region. This suggests that we base our judgments of 'us' versus 'them' more on the structure of the group as a whole than on our own similarity with individual group members. Understanding how we determine whether others are on the same ‘team’ as ourselves could ultimately help us find ways to reduce bias and discrimination between groups.

Social relations and presence of others predict bystander intervention: Evidence from violent incidents captured on CCTV

Are individuals willing to intervene in public violence? Half a century of research on the “bystander effect” suggests that the more bystanders present at an emergency, the less likely each of them is to provide help. However, recent meta‐analytical evidence questions whether this effect generalizes to violent emergencies. Besides the number of bystanders present, an alternative line of research suggests that pre‐existing social relations between bystanders and conflict participants are important for explaining whether bystanders provide help. The current paper offers a rare comparison of both factors—social relations and the number of bystanders present—as predictors of bystander intervention in real‐life violent emergencies. We systematically observed the behavior of 764 bystanders across 81 violent incidents recorded by surveillance cameras in Copenhagen, Denmark. Bystanders were sampled with a case–control design, their behavior was observed and coded, and the probability of intervention was estimated with multilevel regression analyses. The results confirm our predicted association between social relations and intervention. However, rather than the expected reversed bystander effect, we found a classical bystander effect, as bystanders were less likely to intervene with increasing bystander presence. The effect of social relations on intervention was larger in magnitude than the effect of the number of bystanders. We assess these findings in light of recent discussions about the influence of group size and social relations in human helping. Further, we discuss the utility of video data for the assessment of real‐life bystander behavior.

Social buffering of stress in a group-living fish

Living in groups affords individuals many benefits, including the opportunity to reduce stress. In mammals, such 'social buffering' of stress is mediated by affiliative relationships and production of the neuropeptide oxytocin, but whether these mechanisms facilitate social buffering across vertebrates remains an open question. Therefore, we evaluated whether the social environment influenced the behavioural and physiological recovery from an acute stressor in a group-living cichlid, Neolamprologus pulcher. Individual fish that recovered with their social group displayed lower cortisol levels than individuals that recovered alone. This social buffering of the stress response was associated with a tendency towards lower transcript abundance of arginine vasotocin and isotocin in the preoptic area of the brain, suggesting reduced neural activation of the stress axis. Individuals that recovered with their social group quickly resumed normal behaviour but received fewer affiliative acts following the stressor. Further experiments revealed similar cortisol levels between individuals that recovered in visual contact with their own social group and those in visual contact with a novel but non-aggressive social group. Collectively, our results suggest that affiliation and familiarity per se do not mediate social buffering in this group-living cichlid, and the behavioural and physiological mechanisms responsible for social buffering may vary across vertebrates.

Social buffering of stress in a group-living fish

Living in groups affords individuals many benefits, including the opportunity to reduce stress. In mammals, such 'social buffering' of stress is mediated by affiliative relationships and production of the neuropeptide oxytocin, but whether these mechanisms facilitate social buffering across vertebrates remains an open question. Therefore, we evaluated whether the social environment influenced the behavioural and physiological recovery from an acute stressor in a group-living cichlid, Neolamprologus pulcher. Individual fish that recovered with their social group displayed lower cortisol levels than individuals that recovered alone. This social buffering of the stress response was associated with a tendency towards lower transcript abundance of arginine vasotocin and isotocin in the preoptic area of the brain, suggesting reduced neural activation of the stress axis. Individuals that recovered with their social group quickly resumed normal behaviour but received fewer affiliative acts following the stressor. Further experiments revealed similar cortisol levels between individuals that recovered in visual contact with their own social group and those in visual contact with a novel but non-aggressive social group. Collectively, our results suggest that affiliation and familiarity per se do not mediate social buffering in this group-living cichlid, and the behavioural and physiological mechanisms responsible for social buffering may vary across vertebrates.

Social buffering of stress in a group-living fish

Living in groups affords individuals many benefits, including the opportunity to reduce stress. In mammals, such 'social buffering' of stress is mediated by affiliative relationships and production of the neuropeptide oxytocin, but whether these mechanisms facilitate social buffering across vertebrates remains an open question. Therefore, we evaluated whether the social environment influenced the behavioural and physiological recovery from an acute stressor in a group-living cichlid, Neolamprologus pulcher. Individual fish that recovered with their social group displayed lower cortisol levels than individuals that recovered alone. This social buffering of the stress response was associated with a tendency towards lower transcript abundance of arginine vasotocin and isotocin in the preoptic area of the brain, suggesting reduced neural activation of the stress axis. Individuals that recovered with their social group quickly resumed normal behaviour but received fewer affiliative acts following the stressor. Further experiments revealed similar cortisol levels between individuals that recovered in visual contact with their own social group and those in visual contact with a novel but non-aggressive social group. Collectively, our results suggest that affiliation and familiarity per se do not mediate social buffering in this group-living cichlid, and the behavioural and physiological mechanisms responsible for social buffering may vary across vertebrates.

Divergence in gut microbial communities mirrors a social group fission event in a black-and-white colobus monkey (Colobus vellerosus)

Host behavior and social factors have increasingly been implicated in structuring the composition of gut microbial communities. In social animals, distinct microbial communities characterize different social groups across a variety of taxa, although little longitudinal research has been conducted that demonstrates how this divergence occurs. Our study addresses this question by characterizing the gut microbial composition of an African Old World monkey, the black-and-white colobus (Colobus vellerosus), before and after a social group fission event. Gut microbial taxonomic composition of these monkeys was profiled using the V-4 hypervariable region of the bacterial 16S ribosomal RNA gene, and pairwise-relatedness values were calculated for all individuals using 17 short tandem repeat loci and partial pedigree information. The two social groups in this study were found to harbor distinct microbial signatures after the fission event from which they emerged, while these communities were not divergent in the same individuals before this event. Three genera were found to differ in abundance between the two new social groups: Parabacteroides, Coprococcus, and Porphyromonadaceae. Additionally, although this fission happened partially along lines of relatedness, relatedness did not structure the differences that we found. Taken together, this study suggests that distinct gut microbial profiles can emerge in social groups in <1 year and recommends further work into more finely mapping the timescales, causes, and potentially adaptive effects of this recurring trend toward distinct group microbial signatures.

Push and pull factors driving movement in a social mammal: context dependent behavioral plasticity at the landscape scale

Understanding how key parameters (e.g., density, range-size, and configuration) can affect animal movement remains a major goal of population ecology. This is particularly important for wildlife disease hosts, such as the European badger Meles meles, a reservoir of Mycobacterium bovis. Here we show how movements of 463 individuals among 223 inferred group territories across 755 km² in Ireland were affected by sex, age, past-movement history, group composition, and group size index from 2009 to 2012. Females exhibited a greater probability of moving into groups with a male-biased composition, but male movements into groups were not associated with group composition. Male badgers were, however, more likely to make visits into territories than females. Animals that had immigrated into a territory previously were more likely to emigrate in the future. Animals exhibiting such “itinerant” movement patterns were more likely to belong to younger age classes. Inter-territorial movement propensity was negatively associated with group size, indicating that larger groups were more stable and less attractive (or permeable) to immigrants. Across the landscape, there was substantial variation in inferred territory-size and movement dynamics, which was related to group size. This represents behavioral plasticity previously only reported at the scale of the species’ biogeographical range. Our results highlight how a “one-size-fits-all” explanation of badger movement is likely to fail under varying ecological contexts and scales, with implications for bovine tuberculosis management.

Social Information on Fear and Food Drives Animal Grouping and Fitness

Empirical studies in select systems suggest that social information-the incidental or deliberate information produced by animals and available to other animals-can fundamentally shape animal grouping behavior. However, to understand the role of social information in animal behavior and fitness, we must establish general theory that quantifies effects of social information across ecological contexts and generates expectations that can be applied across systems. Here we used dynamic state variable modeling to isolate effects of social information about food and predators on grouping behavior and fitness. We characterized optimal behavior from a set of strategies that included grouping with different numbers of conspecifics or heterospecifics and the option to forage or be vigilant over the course of a day. We show that the use of social information alone increases grouping behavior but constrains group size to limit competition, ultimately increasing individual fitness substantially across various ecological contexts. We also found that across various contexts, foraging in mixed-species groups is generally better than foraging in conspecific groups, supporting recent theory on competition-information quality trade-offs. Our findings suggest that multiple forms of social information shape animal grouping and fitness, which are sensitive to resource availability and predation pressure that determine information usefulness.

Young Children's Motor Interference Is Influenced by Novel Group Membership

From early childhood onward, individuals use behavior copying to communicate liking and belonging. This non-verbal signal of affiliation is especially relevant in the context of social groups and indeed both children and adults copy in-group more than out-group members. Given the societal importance of inter-group interactions, it is imperative to understand the mechanistic level at which group modulations of copying occur early in development. The current study was designed to investigate the effect of novel group membership on young children’s motor behavior during a simultaneous movement-observation and -execution task. Four- to six-year-olds (n = 65) first gained membership to one of two novel groups based on their color preference and put on a vest in their chosen color. Subsequently, they were instructed to draw a straight line back-and-forth on a tablet computer that was concurrently displaying a stimulus video in which a model moved her arm congruently or incongruently to the child’s instructed direction. In half of the stimulus videos the model belonged to the in-group, while in the other half the model belonged to the out-group, as identified by the color of her dress. The deviations into the uninstructed direction of the children’s drawings were quantified as a measure of how much observing the models’ behaviors interfered with executing their own behaviors. The motor interference effect, namely higher deviations in the incongruent trials than in the congruent trials, was found only for the out-group condition. An additional manipulation of whether the models’ arms followed a biological or non-biological velocity profile had little effect on children’s motor interference. The results are interpreted in the context of the explicit coordinative nature of the task as an effect of heightened attention toward interacting with an out-group member. This study demonstrates that already during early childhood, novel group membership dynamically influences behavior processing as a function of interaction context.

Manipulation of the phenotypic appearance of individuals in groups of laying hens: effects on stress and immune-related variables

This study evaluated whether phenotypic appearance (PA) alteration during two developmental phases in laying hens, reared in two different group sizes, affects stress and immune responses. After hatching, 750 chicks were randomly assigned to 30 pens at a group size of either 10 or 40 birds. Then, the appearance of 0, 30, 50, 70 or 100% of the chicks in each pen was altered by blackdyeing their head feathers (marked); remaining chicks were unmarked. At 32 weeks, basal and postacute stress plasma corticosterone concentration, leukocyte counts, phytohemagglutinin-p lymphoproliferative and primary antibody responses were measured in six birds/pen. Analysis of variances (ANOVAs) showed no differences among treatment combinations. In a second phase, birds within initially homogeneous pens were sequentially either marked or had dye bleached to alter PA of 70% of hens in each flock (= group in a pen). Hens within initially heterogeneous pens remained unaltered as controls. The above variables were remeasured. Hens in phenotypically manipulated pens showed modified leukocyte counts compared to hens in control pens, indicating a chronic stress reaction in all penmates (whether individual PA was altered or not). Social isolation increased plasma corticosterone concentration. However, within groups of n = 40, phenotypically unaltered hens had lower responses than their altered penmate counterparts, suggesting that remaining in a stable PA group aids better coping with challenges. Although all hens in manipulated pens showed modified leukocyte counts, their antibody and lymphoproliferative responses did not differ from controls suggesting that all groupmates were able to immunologically cope with the challenges presented, within the timeframe evaluated.

Social identification moderates the effect of crowd density on safety at the Hajj

Crowd safety is a major concern for those attending and managing mass gatherings, such as the annual Hajj or pilgrimage to Mecca (also called Makkah). One threat to crowd safety at such events is crowd density. However, recent research also suggests that psychological membership of crowds can have positive benefits. We tested the hypothesis that the effect of density on safety might vary depending on whether there is shared social identification in the crowd. We surveyed 1,194 pilgrims at the Holy Mosque, Mecca, during the 2012 Hajj. Analysis of the data showed that the negative effect of crowd density on reported safety was moderated by social identification with the crowd. Whereas low identifiers reported reduced safety with greater crowd density, high identifiers reported increased safety with greater crowd density. Mediation analysis suggested that a reason for these moderation effects was the perception that other crowd members were supportive. Differences in reported safety across national groups (Arab countries and Iran compared with the rest) were also explicable in terms of crowd identification and perceived support. These findings support a social identity account of crowd behavior and offer a novel perspective on crowd safety management.

Content analysis of neurodegenerative and mental diseases social groups

This article aims to characterize the different types of Facebook and Twitter groups for different mental diseases, their purposes, and their functions. We focused the search on depressive disorders, dementia, and Alzheimer's and Parkinson's diseases and examined the Facebook (www.facebook.com) and Twitter (www.twitter.com) groups. We used four assessment criteria: (1) purpose, (2) type of creator, (3) telehealth content, and (4) free-text responses in surveys and interviews. We observed a total of 357 Parkinson groups, 325 dementia groups, 853 Alzheimer groups, and 1127 depression groups on Facebook and Twitter. Moreover, we analyze the responses provided by different users. The survey and interview responses showed that many people were interested in using social networks to support and help in the fight against these diseases. The results indicate that social networks are acceptable by users in terms of simplicity and utility. People use them for finding support, information, self-help, advocacy and awareness, and for collecting funds.