Conformity-Driven Agents Support Ordered Phases in the Spatial Public Goods Game

We investigate the spatial Public Goods Game in the presence of fitness-driven and conformity-driven agents. This framework usually considers only the former type of agents, i.e., agents that tend to imitate the strategy of their fittest neighbors. However, whenever we study social systems, the evolution of a population might be affected also by social behaviors as conformism, stubbornness, altruism, and selfishness. Although the term evolution can assume different meanings depending on the considered domain, here it corresponds to the set of processes that lead a system towards an equilibrium or a steady-state. We map fitness to the agents' payoff so that richer agents are those most imitated by fitness-driven agents, while conformity-driven agents tend to imitate the strategy assumed by the majority of their neighbors. Numerical simulations aim to identify the nature of the transition, on varying the amount of the relative density of conformity-driven agents in the population, and to study the nature of related equilibria. Remarkably, we find that conformism generally fosters ordered cooperative phases and may also lead to bistable behaviors.Comment: 13 pages, 5 figure

Statistical Physics of the Spatial Prisoner's Dilemma with Memory-Aware Agents

We introduce an analytical model to study the evolution towards equilibrium in spatial games, with `memory-aware' agents, i.e., agents that accumulate their payoff over time. In particular, we focus our attention on the spatial Prisoner's Dilemma, as it constitutes an emblematic example of a game whose Nash equilibrium is defection. Previous investigations showed that, under opportune conditions, it is possible to reach, in the evolutionary Prisoner's Dilemma, an equilibrium of cooperation. Notably, it seems that mechanisms like motion may lead a population to become cooperative. In the proposed model, we map agents to particles of a gas so that, on varying the system temperature, they randomly move. In doing so, we are able to identify a relation between the temperature and the final equilibrium of the population, explaining how it is possible to break the classical Nash equilibrium in the spatial Prisoner's Dilemma when considering agents able to increase their payoff over time. Moreover, we introduce a formalism to study order-disorder phase transitions in these dynamics. As result, we highlight that the proposed model allows to explain analytically how a population, whose interactions are based on the Prisoner's Dilemma, can reach an equilibrium far from the expected one; opening also the way to define a direct link between evolutionary game theory and statistical physics.Comment: 7 pages, 5 figures. Accepted for publication in EPJ-

On the effect of memory on the Prisoner's Dilemma game in correlated networks

Game theory is fundamental to understanding cooperation between agents. Mainly, the Prisoner's Dilemma is a well-known model that has been extensively studied in complex networks. However, although the emergence of cooperation has been investigated before, the influence of memory in its evolution is not well understood. This paper presents a detailed study of cooperation dynamics in which agents have memory. We simulate the evolutionary Prisoner's dilemma game on random, scale-free and networks presenting degree-degree correlation. Through extensive simulations, we show that assortativity can improve cooperation when the temptation to defect increases. Moreover, we show that the inclusion of memory decreases the network structure influence. Our results contribute to understanding the role of the network structure and the player's memory of cooperation

Moral Intuitions and Organizational Culture

Many efforts to understand and respond to a succession of corporate scandals over the last few years have underscored the importance of organizational culture in shaping the behavior of individuals. This focus reflects appreciation that even if an organization has adopted elaborate rules and policies designed to ensure legal compliance and ethical behavior, those pronouncements will be ineffective if other norms and incentives promote contrary conduct. Responding to the call for creating and sustaining an ethical culture in organizations requires appreciating the subtle ways in which various characteristics of an organization may work in tandem or at cross-purposes in shaping behavior. The idea is to identify the influences likely to be most important, analyze how people are apt to respond to them, and revise them if necessary so that they create the right kinds of incentives when individuals are deciding how to act. This can be a tall order even if we assume that most behavior is the result of a deliberative process that weighs multiple risks and rewards. It’s even more daunting if we accept the notion that conscious deliberation typically plays but a minor role in shaping behavior. A focus on what two scholars describe as “the unbearable automaticity of being” posits that most of a person’s everyday life is determined not by conscious intentions and deliberate choices but by mental processes outside of conscious awareness. In this article, I discuss a particular strand of research that is rooted in the study of non-conscious mental processes, and consider its implications for ethics and culture in the organizational setting. This is work on the process that we use to identify and respond to situations that raise what we think of as distinctly moral questions. A growing body of research suggests that a large portion of this process involves automatic non-conscious cognitive and emotional reactions rather than conscious deliberation. One way to think of these reactions is that they reflect reliance on moral intuitions. When such intuitions arise, we don’t engage in moral reasoning in order to arrive at a conclusion. Instead, we do so in order to justify a conclusion that we’ve already reached. In other words, moral conclusions precede, rather than follow, moral reasoning. If this research accurately captures much of our moral experience, what does it suggest about what’s necessary to foster an ethical organizational culture? At first blush, the implications seem unsettling. The non-conscious realm is commonly associated with irrational and arbitrary impulses, and morality often is characterized as the hard-won achievement of reason over these unruly forces. If most of our moral judgments are the product of non-conscious processes, how can we hope to understand, much less influence, our moral responses? Are moral reactions fundamentally inscrutable and beyond appeals to reason? If reason has no persuasive force, does appreciation of the non-conscious source of our moral judgments suggest that any effort to promote ethical conduct must rest on a crude behaviorism that manipulates penalties and rewards? I believe that acknowledging the prominent role of non-conscious processes in shaping moral responses need not inevitably lead either to fatalism or Skinnerian behaviorism. Research has begun to shed light on how these processes operate. Related work has suggested how our moral responses may be rooted in human evolution. This perspective focuses on the ways in which our capacity for moral judgment is embedded in physical and mental processes that have provided an adaptive advantage in human evolution. These bodies of research contribute to a richer portrait of human cognition and behavior that can be valuable in thinking about how to promote ethical awareness and conduct. As Owen Flanagan has put it, “seeing clearly the kinds of persons we are is a necessary condition for any productive ethical reflection.” If there were such a thing as a normative theory of human movement, it would be futile if it exhorted us to fly. Efforts to create an organizational culture that encouraged people to fly would be doomed as well. In thinking about ethics, we need to have a sense of what lies between simply accommodating what we tend to do and demanding that we fly. My hope is that this article takes a small step in that direction

Evolutionary dynamics of group formation

This is an open access article distributed under the terms of the Creative Commons Attribution License CC BY 4.0 https://creativecommons.org/licenses/by/4.0/ which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Group formation is a quite ubiquitous phenomenon across different animal species, whose individuals cluster together forming communities of diverse size. Previous investigations suggest that, in general, this phenomenon might have similar underlying reasons across the interested species, despite genetic and behavioral differences. For instance improving the individual safety (e.g. from predators), and increasing the probability to get food resources. Remarkably, the group size might strongly vary from species to species, e.g. shoals of fishes and herds of lions, and sometimes even within the same species, e.g. tribes and families in human societies. Here we build on previous theories stating that the dynamics of group formation may have evolutionary roots, and we explore this fascinating hypothesis from a purely theoretical perspective, with a model using the framework of Evolutionary Game Theory. In our model we hypothesize that homogeneity constitutes a fundamental ingredient in these dynamics. Accordingly, we study a population that tries to form homogeneous groups, i.e. composed of similar agents. The formation of a group can be interpreted as a strategy. Notably, agents can form a group (receiving a ‘group payoff’), or can act individually (receiving an ‘individual payoff’). The phase diagram of the modeled population shows a sharp transition between the ‘group phase’ and the ‘individual phase’, characterized by a critical ‘individual payoff’. Our results then support the hypothesis that the phenomenon of group formation has evolutionary roots.Peer reviewedFinal Published versio

To compete or to cooperate? Values' impact on perception and action in social dilemma games

Two studies investigated how values affect competitive versus cooperative behavior. Each Study presented a new social-dilemma game, in which participants' interpretations of the dilemma (i.e., their subjective payoff matrix)—and consequently the dominant (i.e., rational) behavioral choice—depended on their values. The Paired Charity Game (Study 1) framed the situation in terms of cooperation. As hypothesized, contribution correlated positively with universalism and benevolence values that reflect concern for others and negatively with power, achievement, and hedonism values that promote self-interests. Furthermore, values, but not traits, predicted the participants' contribution. The Group Charity Game (Study 2) was designed to frame the situation in terms of competition. As hypothesized, contribution correlated positively with emphasizing benevolence over power values. Moreover, the impact of values was stronger when they were rendered accessible, indicating a causal influence of values on behavior. Furthermore, when their value hierarchy was rendered accessible, participants explained their choices in terms of those values that were (a) important to them and (b) relevant to the situation. The findings thus point to the mechanism through which accessible values affect behavior. Taken together, the studies promote our understanding of the value–behavior relationships, by highlighting the impact of values on perception. Copyright © 2010 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79435/1/729_ftp.pd

The right temporoparietal junction during a cooperation dilemma: An rTMS study

Cooperation enhances interpersonal communication and nurtures society. However, efforts to socially cooperate may often evoke conflict. Individuals may selfishly pursue a greater reward or success by exploiting the efforts of other individuals or taking unnecessary risk to oneself. Such a cooperation dilemma is highly prevalent in real life; thus, it has been studied in various disciplines. Although published functional magnetic resonance imaging studies have shown the involvement of the right temporoparietal junction (TPJ) in resolving a dilemma through cooperation, a causal relationship between the two has rarely been explored. Hence, we investigated this issue by combining repetitive transcranial magnetic stimulation with a priority game task (modified snowdrift game). In this game task, participants and opponent players jointly faced a problem whereby their collaboration was anticipated to defuse the situation. This conflicted with a choice in the participant's self-interest that was more rewarding but risky. We further included conditions with and without explicit social cues using figures describing elderly/pregnant passengers in the game opponent's car, and measured participants' prosocial traits to examine any cue-induced effect as well as the personality-cooperation relationship, respectively. The cooperation ratio was not statistically different in both the no-cue and with-cue conditions between the sham stimulation and inhibitory continuous theta burst stimulation (cTBS). However, after cTBS, in the no-cue condition, the strength of the association between cooperation ratio and empathy traits decreased significantly. These results add to our knowledge about the right TPJ's role in social cognition, which may be extraordinarily complex. This topic is deserving of further examination

Prestige and content biases together shape the cultural transmission of narratives

Context-based cultural transmission biases such as prestige are thought to have been a primary driver in shaping the dynamics of human cultural evolution. However, few empirical studies have measured the importance of prestige relative to other effects, such as the content biases present within transmitted information. Here, we report the findings of an experimental transmission study designed to compare the simultaneous effects of a high- or low-prestige model with the presence of content containing social, survival, emotional, moral, rational, or counterintuitive information. Results from multimodel inference reveal that prestige is a significant factor in determining salience and recall, but that several content biases, specifically social, survival, negative emotional, and biological counterintuitive information, are significantly more influential. Further, we find evidence that prestige serves as a conditional learning strategy when no content cues are available. Our results demonstrate that content biases serve a vital and underappreciated role in cultural transmissionIntroduction Methods - Experimental protocol - Participants - Story production - Recordings - Data coding and transcription - Data analysis - Ethics statement Results - Sample demographics - Participants showed preferential recall of biased information - Content biases were more influential than prestige bias - Transmission biases explain little variance in recall Discussion - Prestige bias has a minor effect on transmission - Prestige is unconsciously employed as a secondary bias - Content biases have distinct effects - Narrative structural features may aid transmission - Implications for the understanding of transmissio