Department of Information Management, Zhejiang University of Finance and Economics, Hangzhou, Zhejiang, People's Republic of China.
Phys Rev E. 2017 Feb;95(2-1):022303. doi: 10.1103/PhysRevE.95.022303. Epub 2017 Feb 9.
Many evolutionary game models for network reciprocity are based on an imitation dynamics, yet how semirational imitators prevail has seldom been explained. Here we use a model to investigate the coevolutionary dynamics of cooperation and partnership adjustment in a polygenic population of semirational imitators and rational payoff maximizers. A rational individual chooses a strategy best responding to its neighbors when updating strategy and switches to a new partner who can bring it the maximal payoff from all candidates when adjusting the partnership. In contrast, a semirational individual imitates its neighbor's strategy directly and adjusts its partnership based upon a simple reputation rule. Individual-based simulations show that cooperation cannot evolve in a population of all best responders even if they can switch their partners to somebody who can reward them best in game playing. However, when imitators exist, a stable community that consists of cooperative imitators emerges. Further, we show that a birth-death selection mechanism can eliminate all best responders, cultivating a social regime of all cooperative imitators. Compared with parallel simulations that assume fixed networks, cooperative imitators are evolutionarily favored, provided they are able to adjust their partners.
许多用于网络互惠性的进化博弈模型都是基于模仿动态的，但很少有解释说明半理性模仿者为何能够盛行。在这里，我们使用一个模型来研究合作和伙伴关系调整的共同进化动力学，该模型是在一个具有半理性模仿者和理性收益最大化者的多基因种群中进行的。理性个体在更新策略时会选择最能响应其邻居的策略，而在调整伙伴关系时则会选择能够从所有候选者中带来最大收益的新伙伴。相比之下，半理性个体直接模仿邻居的策略，并根据简单的声誉规则来调整伙伴关系。基于个体的模拟表明，即使最佳响应者可以将其伙伴切换为在博弈中能够最佳奖励他们的人，合作也无法在所有最佳响应者的群体中进化。然而，当存在模仿者时，一个由合作模仿者组成的稳定社区就会出现。此外，我们还表明，一个出生-死亡选择机制可以消除所有最佳响应者，培养出一种完全由合作模仿者组成的社会制度。与假设固定网络的平行模拟相比，只要合作模仿者能够调整其伙伴关系，它们在进化上就具有优势。
