SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Group action

103

Social relationships have profound effects on health in humans and other primates, but the mechanisms that explain this relationship are not well understood. Using shotgun metagenomic data from wild baboons, we found that social group membership and social network relationships predicted both the taxonomic structure of the gut microbiome and the structure of genes encoded by gut microbial species. Rates of interaction directly explained variation in the gut microbiome, even after controlling for diet, kinship, and shared environments. They therefore strongly implicate direct physical contact among social partners in the transmission of gut microbial species. We identified 51 socially structured taxa, which were significantly enriched for anaerobic and non-spore-forming lifestyles. Our results argue that social interactions are an important determinant of gut microbiome composition in natural animal populations-a relationship with important ramifications for understanding how social relationships influence health, as well as the evolution of group living.

Concepts: Scientific method, Archaea, Human, Evolution, Understanding, Sociology, Explanation, Group action

28

BACKGROUND: Prior studies have suggested that patients with workers' compensation (WC) related injuries have less successful postsurgical outcomes compared to the general population. The purpose of this study was to determine the functional outcome and return to work for WC patients who have undergone distal biceps tendon repair (DBTR). A group of patients without a WC claim (non-WC) served as a control. METHODS: From July 2002 to December 2009, 60 WC patients and 63 non-WC patients who underwent unilateral, acute (<6 weeks) DBTR and had a minimum of 12 months of postoperative follow-up were contacted. Data pertaining to patient age, sex, handedness, smoking status, occupation, time to return to work, and ability to return to original occupation were obtained. Functional outcomes were primarily assessed with the DASH, DASH-Work Module, and DASH Sports/Performance Arts Module questionnaires. Outcomes in the WC group were compared to the non-WC group. RESULTS: Average length of follow-up was 3.55 years (range, 1.5-8.9) in the WC group and 3.64 years (range, 2.2-8.0) in the non-WC group. Mean DASH, DASH-Work Module, and Sports/Performance Arts Module scores were significantly greater (poorer outcome) in the WC group than in the non-WC group. Average time to return to full duty was 3.95 months in the WC group and 1.35 months in the non-WC group. CONCLUSION: WC patients who underwent distal biceps tendon repair took longer to return to work and had worse DASH scores than non-WC patients.

Concepts: Vector space, Group, Outcome, Workers' compensation, Group action, Simple module

23

Social behavior in mammals is often studied in pairs under artificial conditions, yet groups may rely on more complicated social structures. Here, we use a novel system for tracking multiple animals in a rich environment to characterize the nature of group behavior and interactions, and show strongly correlated group behavior in mice. We have found that the minimal models that rely only on individual traits and pairwise correlations between animals are not enough to capture group behavior, but that models that include third-order interactions give a very accurate description of the group. These models allow us to infer social interaction maps for individual groups. Using this approach, we show that environmental complexity during adolescence affects the collective group behavior of adult mice, in particular altering the role of high-order structure. Our results provide new experimental and mathematical frameworks for studying group behavior and social interactions. DOI:http://dx.doi.org/10.7554/eLife.00759.001.

Concepts: Sociology, Social relation, Collective, Group action

15

Accelerating the search for functional materials is a challenging problem. Here we develop an informatics-guided ab initio approach to accelerate the design and discovery of noncentrosymmetric materials. The workflow integrates group theory, informatics and density-functional theory to uncover design guidelines for predicting noncentrosymmetric compounds, which we apply to layered Ruddlesden-Popper oxides. Group theory identifies how configurations of oxygen octahedral rotation patterns, ordered cation arrangements and their interplay break inversion symmetry, while informatics tools learn from available data to select candidate compositions that fulfil the group-theoretical postulates. Our key outcome is the identification of 242 compositions after screening ∼3,200 that show potential for noncentrosymmetric structures, a 25-fold increase in the projected number of known noncentrosymmetric Ruddlesden-Popper oxides. We validate our predictions for 19 compounds using phonon calculations, among which 17 have noncentrosymmetric ground states including two potential multiferroics. Our approach enables rational design of materials with targeted crystal symmetries and functionalities.

Concepts: Scientific method, Mathematics, Symmetry, Group, Group theory, Symmetry group, Erlangen program, Group action

8

Collective decision-making processes emerge from social feedback networks within a group. Many studies on collective behaviour underestimate the role of individual personality and, as a result, personality is rarely analysed in the context of collective dynamics. Here, we show evidence of sheltering behaviour personality in a gregarious insect (Periplaneta americana), which is characterized by a collective personality at the group level. We also highlight that the individuals within groups exhibited consistent personality traits in their probability of sheltering and total time sheltered during the three trials over one week. Moreover, the group personality, which arises from the synergy between the distribution of behaviour profiles in the group and social amplifications, affected the sheltering dynamics. However, owing to its robustness, personality did not affect the group probability of reaching a consensus. Finally, to prove social interactions, we developed a new statistical method that will be helpful for future research on personality traits and group behaviour. This approach will help to identify the circumstances under which particular group compositions may improve the fitness of individuals in gregarious species.

Concepts: Psychology, Statistics, Sociology, Group action, Crowd psychology

2

Mindfulness-based stress reduction (MBSR) has benefits for those with chronic pain. MBSR typically entails an intensive 8-week intervention. The effects of very brief mindfulness interventions are unknown. Among those with chronic pain, the immediate effects of a 10 min mindfulness-based body scan were compared with a control intervention. Fifty-five adult outpatients were randomly assigned to either: (1) mindfulness-based body scan (n = 27) or (2) a reading about natural history (control group, n = 28), provided via a 10 min audio-recording. Interventions were delivered twice across 24 h; once in the clinic and once in participants' ‘normal’ environment. Immediately before and after listening to the recording, participants rated pain severity, pain related distress, perceived ability for daily activities, perceived likelihood of pain interfering with social relations, and mindfulness. In the clinic, there was a significant reduction in ratings for pain related distress and for pain interfering with social relations for the body scan group compared with the control group (p = 0.005; p = 0.036, respectively). In the normal environment none of the ratings were significantly different between the groups. These data suggest that, in a clinic setting, a brief body scan has immediate benefits for those experiencing chronic pain. These benefits need to be confirmed in the field.

Concepts: Controlling for a variable, Scientific control, Pain, The Normal, Normal distribution, Intervention, Chronic pain, Group action

1

We investigated the effect of structural interdependencies between groups (especially inequality), and interdependencies between individuals on ingroup favoritism in minimal group situations. Previous research has attempted to determine whether ingroup favoritism is produced by categorization or intragroup interdependencies (reciprocation expectations), but recent literature suggests that it is not possible to tease these influences apart. We report two studies that investigate how ingroup favoritism evolves over time in social interaction. The levels of ingroup favoritism were affected by categorization and inequality, and the level of ingroup favoritism changed over time, increasing or decreasing depending on the nature of the initial intergroup structure. We conclude by providing two explanations for this change: emergent norms, and changes to the intergroup situation produced by interaction. Our experiments confirm the value of studying the evolution of minimal group behavior, especially for explaining why low status groups act to preserve intergroup inequalities.

Concepts: Evolution, Effect, Sociology, Affect, Change, Group selection, Interconnectivity, Group action

1

We identify a unique viewpoint on the collective behaviour of intelligent agents. We first develop a highly general abstract model for the possible future lives these agents may encounter as a result of their decisions. In the context of these possibilities, we show that the causal entropic principle, whereby agents follow behavioural rules that maximize their entropy over all paths through the future, predicts many of the observed features of social interactions among both human and animal groups. Our results indicate that agents are often able to maximize their future path entropy by remaining cohesive as a group and that this cohesion leads to collectively intelligent outcomes that depend strongly on the distribution of the number of possible future paths. We derive social interaction rules that are consistent with maximum entropy group behaviour for both discrete and continuous decision spaces. Our analysis further predicts that social interactions are likely to be fundamentally based on Weber’s law of response to proportional stimuli, supporting many studies that find a neurological basis for this stimulus-response mechanism and providing a novel basis for the common assumption of linearly additive ‘social forces’ in simulation studies of collective behaviour.

Concepts: Sociology, Behavior, Social relation, Collective, Group action

1

The aim of this study was to explore how and why participants in structured exercise intervention programs continue or stop exercising after the program is finished. We conducted four focus group interviews with four groups of middle-aged and elderly men (total n = 28) who had participated in exercise interventions involving playing either a team sport (football) or a more individually focused activity (spinning and crossfit). Our results show that different social, organizational and material structures inherent in the different activities shape the subjects' enjoyment of exercise participation, as well as their intention and ability to continue being active. In conclusion, team sport activities seem to be intrinsically motivating to the participants through positive social interaction and play. They are therefore more likely to result in exercise continuation than activities that rely primarily on extrinsic motivation such as the expectation of improved health and well-being.

Concepts: Focus group, Structure, Sociology, Weight loss, Behavior, Motivation, Control flow, Group action

1

Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals' preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution.

Concepts: Psychology, Sociology, Behavior, Motivation, Preference, Utility, Social relation, Group action