Ramazi Pouria, Hessel Jop, Cao Ming
ENgineering and TEchnology institute Groningen (ENTEG), Faculty of Mathematics and Natural Sciences, University of Groningen, Groningen, The Netherlands.
PLoS One. 2015 Apr 29;10(4):e0122205. doi: 10.1371/journal.pone.0122205. eCollection 2015.
For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.
对于一群相互作用的自利主体，我们研究了一些个体的被背叛感和内疚感如何影响平均合作水平。我们将这些感受量化为非对称博弈中的调整收益，在不同情绪下，收益矩阵具有囚徒困境或雪堆博弈的结构。然后我们分析了在一个主体充分混合的群体中合作的演化，其中每个主体都与这样一个收益矩阵相关联。在每个时间步，从群体中随机选择一个主体，根据近视最佳反应更新规则更新其策略。根据模拟结果，降低一部分主体的被背叛感不一定会提高群体中的合作水平。然而，群体对低背叛水平主体的这种抵抗力仅在一定程度上有效，这一程度由收益矩阵和与这些矩阵相关联的主体数量明确决定。我们还考虑了另外两个模型，其中一个主体的背叛因素根据她遇到的合作者和背叛者的数量而波动。在这些情况下，观察到合作水平存在不稳定行为；然而，我们表明可以调整函数中的参数，使整个群体变得合作或背叛。
