Many mechanisms behind the evolution of cooperation, such as reciprocity, indirect reciprocity, and altruistic punishment, require group knowledge of individual actions. But what keeps people cooperating when no one is looking? Conformist norm internalization, the tendency to abide by the behavior of the majority of the group, even when it is individually harmful, could be the answer. In this paper, we analyze a world where (1) there is group selection and punishment by indirect reciprocity but (2) many actions (about half) go unobserved, and therefore unpunished. Can norm internalization fill this 'observation gap' and lead to high levels of cooperation, even when agents may in principle cooperate only when likely to be caught and punished? Specifically, we seek to understand whether adding norm internalization to the strategy space in a public goods game can lead to higher levels of cooperation when both norm internalization and cooperation start out rare. We found the answer to be positive, but, interestingly, not because norm internalizers end up making up a substantial fraction of the population, nor because they cooperate much more than other agent types. Instead, norm internalizers, by polarizing, catalyzing, and stabilizing cooperation, can increase levels of cooperation of other agent types, while only making up a minority of the population themselves.
翻译:Abstract:
许多促进合作演化的机制,例如互惠、间接互惠和利他惩罚,需要群体知晓个体行为。但是当没有人在看的时候,什么能让人们相互合作?顺从的规范内化,即遵循群体多数人行为的倾向,即使在个人受到伤害时仍然遵守,可能是答案。在本文中,我们分析了一个世界,其中存在群体选择和间接互惠的惩罚,但许多行为(约半数)未经观察,因此未受惩罚。规范内化能否填补这种“观察空白”,并在规范内化和合作最初稀缺时带来更高水平的合作?具体而言,我们寻求了解在公共物品博弈中增加规范内化到策略空间是否可以在规范内化和合作起初为稀有时导致更高水平的合作。我们发现答案是肯定的,但是有趣的是,不是因为规范内化者最终占据了人口的相当大部分,也不是因为他们比其他代理人类型更合作。相反,规范内化者通过极化、催化和稳定合作,可以增加其他代理人类型的合作水平,而自己仅占少数人口。