Dynamics of Helping Behavior and Networks in a Small World

To investigate an effect of social interaction on the bystanders' intervention in emergency situations a rescue model was introduced which includes the effects of the victim's acquaintance with bystanders and those among bystanders from a network perspective. This model reproduces the experimental result that the helping rate (success rate in our model) tends to decrease although the number of bystanders $k$ increases. And the interaction among homogeneous bystanders results in the emergence of hubs in a helping network. For more realistic consideration it is assumed that the agents are located on a one-dimensional lattice (ring), then the randomness $p \in [0,1]$ is introduced: the $kp$ random bystanders are randomly chosen from a whole population and the $k-kp$ near bystanders are chosen in the nearest order to the victim. We find that there appears another peak of the network density in the vicinity of $k=9$ and $p=0.3$ due to the cooperative and competitive interaction between the near and random bystanders.Comment: 13 pages, 8 figure

Freezing and Slow Evolution in a Constrained Opinion Dynamics Model

We study opinion formation in a population that consists of leftists, centrists, and rightist. In an interaction between neighboring agents, a centrist and a leftist can become both centrists or leftists (and similarly for a centrist and a rightist). In contrast, leftists and rightists do not affect each other. The initial density of centrists rho_0 controls the evolution. With probability rho_0 the system reaches a centrist consensus, while with probability 1-rho_0 a frozen population of leftists and rightists results. In one dimension, we determine this frozen state and the opinion dynamics by mapping the system onto a spin-1 Ising model with zero-temperature Glauber kinetics. In the frozen state, the length distribution of single-opinion domains has an algebraic small-size tail x^{-2(1-psi)} and the average domain size grows as L^{2*psi}, where L is the system length. The approach to this frozen state is governed by a t^{-psi} long-time tail with psi-->2*rho_0/pi as rho_0-->0.Comment: 4 pages, 6 figures, 2-column revtex4 format, for submission to J. Phys. A. Revision contains lots of stylistic changes and 1 new result; the main conclusions are the sam

Whom to Punish? How observers sanction norm-violating behavior in ostracism situations

When observing ostracism, individuals can either side with the target or the sources of ostracism. Here we demonstrate that side-taking depends on whether the target previously acted in adherence to or in violation of perceived social norms. In four studies, a target behaved either norm-consistently or violated a social norm, and was subsequently either excluded by the sources or was not. Next, participants could sanction the behavior of the observed persons by refraining to assign money (Studies 1 and 2), or by subtracting money from a bonus (Studies 3 and 4). Observers assigned less money to the sources when these excluded a norm-consistent target. However, when the target had violated a social norm before, participants assigned less money to the target instead. These results have far-reaching implications because the (in)actions of neutral individuals can legitimize the sources' behavior, or help a target under attack

Rescue Model for the Bystanders' Intervention in Emergencies

To investigate an effect of social interaction on the bystanders' intervention in emergency situations we introduce a rescue model which includes the effects of the victim's acquaintance with bystanders and those among bystanders. This model reproduces the surprising experimental result that the helping rate tends to decrease although the number of bystanders $k$ increases. The model also shows that given the coupling effect among bystanders, for a certain range of small $k$ the helping rate increases according to $k$ and that coupling effect plays both positive and negative roles in emergencies. Finally we find a broad range of coupling strength to maximize the helping rate.Comment: 10 pages, 4 figure

Volatility clustering and scaling for financial time series due to attractor bubbling

A microscopic model of financial markets is considered, consisting of many interacting agents (spins) with global coupling and discrete-time thermal bath dynamics, similar to random Ising systems. The interactions between agents change randomly in time. In the thermodynamic limit the obtained time series of price returns show chaotic bursts resulting from the emergence of attractor bubbling or on-off intermittency, resembling the empirical financial time series with volatility clustering. For a proper choice of the model parameters the probability distributions of returns exhibit power-law tails with scaling exponents close to the empirical ones.Comment: For related publications see http://www.helbing.or

Studying Paths of Participation in Viral Diffusion Process

Authors propose a conceptual model of participation in viral diffusion process composed of four stages: awareness, infection, engagement and action. To verify the model it has been applied and studied in the virtual social chat environment settings. The study investigates the behavioral paths of actions that reflect the stages of participation in the diffusion and presents shortcuts, that lead to the final action, i.e. the attendance in a virtual event. The results show that the participation in each stage of the process increases the probability of reaching the final action. Nevertheless, the majority of users involved in the virtual event did not go through each stage of the process but followed the shortcuts. That suggests that the viral diffusion process is not necessarily a linear sequence of human actions but rather a dynamic system.Comment: In proceedings of the 4th International Conference on Social Informatics, SocInfo 201

Factors influencing decision-making by social care and health sector professionals in cases of elder financial abuse

This study aimed to identify the factors that have the greatest influence on UK social care and health sector professionals’ certainty that an older person is being financially abused, their likelihood of intervention, and the type of action most likely to be taken. A factorial survey approach, applying a fractional factorial design, was used. Health and social care professionals (n=152) viewed a single sample of 50 elder financial abuse case vignettes; the vignettes contained seven pieces of information (factors). Following multiple regression analysis, incremental F tests were used to compare the impact of each factor on judgements. Factors that had a significant influence on judgements of certainty that financial abuse was occurring included the older person’s mental capacity and the nature of the financial problem suspected. Mental capacity accounted for more than twice the variance in likelihood of action than the type of financial problem. Participants from social care were more likely to act and chose more actions compared to health sector participants. The results are discussed in relation to a bystander intervention model. The impact of the older person’s mental capacity on decision-making suggests the need for training to ensure action is also taken in cases where older people have full mental capacity and are being abused. Training also needs to highlight the more subtle types of financial abuse, the types that appear not to lead to certainty or action.This research was funded by the UK Cross Council, New Dynamics of Ageing programme (Economic and Social Research Council administered) [Grant No. RES-352-25-0026 to Mary Gilhooly (PI)]

"Just Going Through the Motions.…": A Qualitative Exploration of Athlete Perceptions of Social Loafing in Training and Competition Contexts - Implications for Team Sport Coaches

Semi-structured interviews were conducted with twenty team sport athletes representing a range of different sports with the aim of investigating their views relating to social loafing in training and competition. General themes investigated and subsequent content analysis highlighted factors that promote or reduce the extent of social loafing. Determinants of self-loafing were grouped according to three distinct categories: Group processes; Task characteristics and Individual perceptions. Social loafing among others was perceived to be prevalent in both the training and competition scenarios with more examples of social loafing provided in the training situation. The signs of social loafing were grouped according to the following themes: Cognitive & Emotional, Behavioural, Communication and Player Intuition. Consequences of social loafing were found to be detrimental to the effort and performance of both the individual and the team. Athletes were also able to differentiate between perceived social loafing and the perceived use of ‘strategic rest’ in team sports. Implications for the coaching process are far reaching with the need to develop an effective team culture and to provide training sessions that are interesting, engaging and relevant

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

Increased costs reduce reciprocal helping behaviour of humans in a virtual evacuation experiment

Altruistic behaviour is widespread and highly developed in humans and can also be found in some animal species. It has been suggested that altruistic tendencies can depend on costs, benefits and context. Here, we investigate the changes in the occurrence of helping behaviour in a computer-based experiment that simulates an evacuation from a building exploring the effect of varying the cost to help. Our findings illuminate a number of key mechanistic aspects of human decision-making about whether to help or not. In a novel situation where it is difficult to assess the risks associated with higher costs, we reproduce the finding that increasing costs reduce helping and find that the reduction in the frequency of helping behaviour is gradual rather than a sudden transition for a threshold cost level. Interestingly, younger and male participants were more likely to help. We provide potential explanations for this result relating to the nature of our experiment. Finally, we find no evidence that participants in our experiment plan ahead over two consecutive, inter-dependent helping opportunities when conducting cost-benefit trade-offs in spontaneous decisions. We discuss potential applications of our findings to research into decision-making during evacuations