Nirjhor Md Sams Afif, Nakamaru Mayuko
School of Environment and Society, Tokyo Institute of Technology, 3-3-6, Shibaura, Minato, Tokyo 108-0023, Japan.
R Soc Open Sci. 2023 Mar 8;10(3):220856. doi: 10.1098/rsos.220856. eCollection 2023 Mar.
Evolution of cooperation is a puzzle in evolutionary biology and social sciences. Previous studies assumed that players are equal and have symmetric relationships. In our society, players are in different roles, have an asymmetric relationship and cooperate together. We focused on the linear division of labour in a unidirectional chain that has finite roles, each of which is assigned to one group with cooperators and defectors. A cooperator in an upstream group produces and modifies a product, paying a cost of cooperation, and hands it to a player in a downstream group who obtains the benefit from the product. If players in all roles cooperate, a final product can be completed. However, if a player in a group chooses defection, the division of labour stops, the final product cannot be completed and all players in all roles suffer damage. By using the replicator equations of the asymmetric game, we investigate which sanction system promotes the evolution of cooperation in the division of labour. We find that not the benefit of the product but the cost of cooperation matters to the evolutionary dynamics and that the probability of finding a defector determines which sanction system promotes the evolution of cooperation.
合作的进化是进化生物学和社会科学中的一个难题。以往的研究假定参与者是平等的且具有对称关系。在我们的社会中，参与者扮演着不同的角色，具有不对称关系并共同合作。我们关注的是单向链条中的线性分工，该链条具有有限的角色，每个角色分配给一个包含合作者和背叛者的群体。上游群体中的一个合作者生产并修改一种产品，付出合作成本，然后将其交给下游群体中的一个参与者，该参与者从产品中获得收益。如果所有角色的参与者都合作，最终产品就能完成。然而，如果一个群体中的参与者选择背叛，分工就会停止，最终产品无法完成，所有角色的所有参与者都会受损。通过使用非对称博弈的复制方程，我们研究哪种制裁系统能促进分工中合作的进化。我们发现，对进化动态起关键作用的不是产品的收益而是合作成本，并且发现背叛者的概率决定了哪种制裁系统能促进合作的进化。
