2,254 research outputs found
Evolution of cooperation driven by zealots
Recent experimental results with humans involved in social dilemma games
suggest that cooperation may be a contagious phenomenon and that the selection
pressure operating on evolutionary dynamics (i.e., mimicry) is relatively weak.
I propose an evolutionary dynamics model that links these experimental findings
and evolution of cooperation. By assuming a small fraction of (imperfect)
zealous cooperators, I show that a large fraction of cooperation emerges in
evolutionary dynamics of social dilemma games. Even if defection is more
lucrative than cooperation for most individuals, they often mimic cooperation
of fellows unless the selection pressure is very strong. Then, zealous
cooperators can transform the population to be even fully cooperative under
standard evolutionary dynamics.Comment: 5 figure
Solving Optimization Problems by the Public Goods Game
This document is the Accepted Manuscript version of the following article: Marco Alberto Javarone, āSolving optimization problems by the public goods gameā, The European Physical Journal B, 90:17, September 2017. Under embargo. Embargo end date: 18 September 2018. The final, published version is available online at doi: https://doi.org/10.1140/epjb/e2017-80346-6. Published by Springer Berlin Heidelberg.We introduce a method based on the Public Goods Game for solving optimization tasks. In particular, we focus on the Traveling Salesman Problem, i.e. a NP-hard problem whose search space exponentially grows increasing the number of cities. The proposed method considers a population whose agents are provided with a random solution to the given problem. In doing so, agents interact by playing the Public Goods Game using the fitness of their solution as currency of the game. Notably, agents with better solutions provide higher contributions, while those with lower ones tend to imitate the solution of richer agents for increasing their fitness. Numerical simulations show that the proposed method allows to compute exact solutions, and suboptimal ones, in the considered search spaces. As result, beyond to propose a new heuristic for combinatorial optimization problems, our work aims to highlight the potentiality of evolutionary game theory beyond its current horizons.Peer reviewedFinal Accepted Versio
Effectiveness of conditional punishment for the evolution of public cooperation
Collective actions, from city marathons to labor strikes, are often mass-driven and subject to the snowball effect. Motivated by this, we study evolutionary advantages of conditional punishment in the spatial public goods game. Unlike unconditional punishers who always impose the same fines on defectors, conditional punishers do so proportionally with the number of other punishers in the group. Phase diagrams in dependence on the punishment fine and cost reveal that the two types of punishers cannot coexist. Spontaneous coarsening of the two strategies leads to an indirect territorial competition with the defectors, which is won by unconditional punishers only if the sanctioning is inexpensive. Otherwise conditional punishers are the victors of the indirect competition, indicating that under more realistic conditions they are indeed the more effective strategy. Both continuous and discontinuous phase transitions as well as tricritical points characterize the complex evolutionary dynamics, which is due to multipoint interactions that are introduced by conditional punishment. We propose indirect territorial competition as a generally applicable mechanism relying on pattern formation, by means of which spatial structure can be utilized by seemingly subordinate strategies to avoid evolutionary extinction
Simple bots breed social punishment in humans
Costly punishment has been suggested as a key mechanism for stabilizing
cooperation in one-shot games. However, recent studies have revealed that the
effectiveness of costly punishment can be diminished by second-order free
riders (i.e., cooperators who never punish defectors) and antisocial punishers
(i.e., defectors who punish cooperators). In a two-stage prisoner's dilemma
game, players not only need to choose between cooperation and defection in the
first stage, but also need to decide whether to punish their opponent in the
second stage. Here, we extend the theory of punishment in one-shot games by
introducing simple bots, who consistently choose prosocial punishment and do
not change their actions over time. We find that this simple extension of the
game allows prosocial punishment to dominate in well-mixed and networked
populations, and that the minimum fraction of bots required for the dominance
of prosocial punishment monotonically increases with increasing dilemma
strength. Furthermore, if humans possess a learning bias toward a "copy the
majority" rule or if bots are present at higher degree nodes in scale-free
networks, the fully dominance of prosocial punishment is still possible at a
high dilemma strength. These results indicate that introducing bots can be a
significant factor in establishing prosocial punishment. We therefore, provide
a novel explanation for the evolution of prosocial punishment, and note that
the contrasting results that emerge from the introduction of different types of
bots also imply that the design of the bots matters.Comment: 12 pages, 4 figure
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