Center for Intelligent and Networked Systems, Department of Automation and TNList, Tsinghua University, Beijing, 100084, China.
Center for Systems and Control, College of Engineering, Peking University, Beijing, 100871, China.
Sci Rep. 2017 Oct 25;7(1):14015. doi: 10.1038/s41598-017-12823-4.
In explaining the pressing issue in biology and social sciences how cooperation emerges in a population of self-interested individuals, researchers recently pay intensive attentions to the role altruistic punishment plays. However, as higher-order cooperators, survival of punishers is puzzling due to their extra cost in regulating norm violators. Previous works have highlighted the importance of individual mobility in promoting cooperation. Yet its effect on punishers remains to be explored. In this work we incorporate this feature into modeling the behavior of punishers, who are endowed with a choice between leaving current place or staying and punishing defectors. Results indicate that optimal mobility level of punishers is closely related to the cost of punishing. For considerably large cost, there exists medium tendency of migration which favors the survival of punishers. This holds for both the direct competition between punishers and defectors and the case where cooperators are involved, and can also be observed when various types of punishers with different mobility tendencies fight against defectors simultaneously. For cheap punishment, mobility does not provide with punishers more advantage even when they are initially rare. We hope our work provide more insight into understanding the role individual mobility plays in promoting public cooperation.
在解释生物学和社会科学中的紧迫问题——在一个由自利个体组成的群体中，合作是如何产生的——时，研究人员最近密切关注利他惩罚所扮演的角色。然而，作为更高层次的合作者，惩罚者的生存是令人困惑的，因为他们在监管规范违规者方面会产生额外的成本。先前的工作强调了个体流动性在促进合作方面的重要性。然而，它对惩罚者的影响仍有待探索。在这项工作中，我们将这一特征纳入到惩罚者行为的建模中，惩罚者在离开当前位置或留下来惩罚违规者之间有一个选择。结果表明，惩罚者的最佳流动水平与惩罚的成本密切相关。对于相当大的成本，存在中等程度的迁移趋势，有利于惩罚者的生存。这既适用于惩罚者和违规者之间的直接竞争，也适用于合作者参与的情况，当具有不同流动倾向的各种类型的惩罚者同时对抗违规者时，也可以观察到这种情况。对于廉价的惩罚，即使惩罚者最初很少，流动性也不能为他们提供更多的优势。我们希望我们的工作能为理解个体流动性在促进公共合作方面所起的作用提供更多的见解。
