Social diversity favors the emergence of cooperative behavior

Throughout their life, humans often engage in public goods games in situations ranging from family related issues to global warming. In all cases, the tragedy of the commons threatens the possibility of reaching the optimal solution associated with global cooperation. Up to now, individuals have been treated as equivalent in all respects, in sharp contrast with real life situations, where diversity abounds. Here we discuss the results reported in [Santos et al. Nature (2008) 454:213-6], where we show how social diversity provides an escape from this paradox. We investigate the impact of social diversity in the evolution of cooperation in complex networks of interaction. We show that the diversity in the number and size of the collective endeavors each individual participates and with the individual contribution to each investment promotes cooperation. The enhancement of cooperation is particularly strong when both wealth and social ties follow a power-law distribution, providing clues on the self-organization of social communities.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

The evolution of prompt reaction to adverse ties

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Adaptive Contact Networks Change Effective Disease Infectiousness and Dynamics

Human societies are organized in complex webs that are constantly reshaped by a social dynamic which is influenced by the information individuals have about others. Similarly, epidemic spreading may be affected by local information that makes individuals aware of the health status of their social contacts, allowing them to avoid contact with those infected and to remain in touch with the healthy. Here we study disease dynamics in finite populations in which infection occurs along the links of a dynamical contact network whose reshaping may be biased based on each individual's health status. We adopt some of the most widely used epidemiological models, investigating the impact of the reshaping of the contact network on the disease dynamics. We derive analytical results in the limit where network reshaping occurs much faster than disease spreading and demonstrate numerically that this limit extends to a much wider range of time scales than one might anticipate. Specifically, we show that from a population-level description, disease propagation in a quickly adapting network can be formulated equivalently as disease spreading on a well-mixed population but with a rescaled infectiousness. We find that for all models studied here – SI, SIS and SIR – the effective infectiousness of a disease depends on the population size, the number of infected in the population, and the capacity of healthy individuals to sever contacts with the infected. Importantly, we indicate how the use of available information hinders disease progression, either by reducing the average time required to eradicate a disease (in case recovery is possible), or by increasing the average time needed for a disease to spread to the entire population (in case recovery or immunity is impossible)

Stochastic simulation of the chemoton

Gánti's chemoton model is an illustrious example of a minimal cell model. It is composed of three stoichiometrically coupled autocatalytic subsystems: a metabolism, a template replication process, and a membrane enclosing the other two. Earlier studies on chemoton dynamics yield inconsistent results. Furthermore, they all appealed to deterministic simulations, which do not take into account the stochastic effects induced by small population sizes. We present, for the first time, results of a chemoton simulation in which these stochastic effects have been taken into account. We investigate the dynamics of the system and analyze in depth the mechanisms responsible for the observed behavior. Our results suggest that, in contrast to the most recent study by Munteanu and Solé, the stochastic chemoton reaches a unique stable division time after a short transient phase. We confirm the existence of an optimal template length and show that this is a consequence of the monomer concentration, which depends on the template length and the initiation threshold. Since longer templates imply shorter division times, these results motivate the selective pressure toward longer templates observed in nature.info:eu-repo/semantics/publishe

Emergence of cooperation in adaptive social networks

Proceedings of the European conference on Artificial Life. Budapest, Hungary, 2009.info:eu-repo/semantics/publishe

Behavioral differences and the evolution of cooperation in adaptive social networks

Cooperation is essential in every society, but puzzling from an evolutionary perspective. Here, we discuss the work published in [11], where we address the role of behavioral differences - ubiquitous among Humans - in the evolution of cooperation. We study a model in which individuals interact along the edges of a complex network, engaging in social dilemmas of cooperation. The structure of the network changes in time, as new interactions arise whereas old ones disappear. Interactions may last long or brief, depending on the behavior of the individuals involved. When dissatisfied about a partner, some will try to break contact as soon as possible, whereas others will remain in touch. We adopt the framework of evolutionary game theory (EGT) and show how diversity in response to unwanted social interactions boosts cooperation. Moreover, diversity remains once cooperation sets in, providing the means to establish cooperation as a robust evolutionary strategy.Proceedings of the Benelux conference on Artificial Intelligence. Eindhoven, the NetherlandsSCOPUS: cp.pinfo:eu-repo/semantics/publishe

Reacting differently to adverse ties promotes cooperation in social networks

102:058105info:eu-repo/semantics/publishe

Emergence of fairness in repeated group interactions.

Often groups need to meet repeatedly before a decision is reached. Hence, most individual decisions will be contingent on decisions taken previously by others. In particular, the decision to cooperate or not will depend on one's own assessment of what constitutes a fair group outcome. Making use of a repeated N-person prisoner's dilemma, we show that reciprocation towards groups opens a window of opportunity for cooperation to thrive, leading populations to engage in dynamics involving both coordination and coexistence, and characterized by cycles of cooperation and defection. Furthermore, we show that this process leads to the emergence of fairness, whose level will depend on the dilemma at stake.Journal Articleinfo:eu-repo/semantics/publishe

Reacting differently to adverse ties promotes the evolution of cooperation

info:eu-repo/semantics/publishe