Junior Research Group Evolution of Cooperation and Prosocial Behaviour, Courant Research Centre Evolution of Social Behaviour, University of Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.
Ecol Lett. 2011 Jun;14(6):546-51. doi: 10.1111/j.1461-0248.2011.01615.x. Epub 2011 Apr 4.
The ubiquity of cooperation in nature is puzzling because cooperators can be exploited by defectors. Recent theoretical work shows that if dynamic networks define interactions between individuals, cooperation is favoured by natural selection. To address this, we compare cooperative behaviour in multiple but independent repeated games between participants in static and dynamic networks. In the latter, participants could break their links after each social interaction. As predicted, we find higher levels of cooperation in dynamic networks. Through biased link breaking (i.e. to defectors) participants affected their social environment. We show that this link-breaking behaviour leads to substantial network clustering and we find primarily cooperators within these clusters. This assortment is remarkable because it occurred on top of behavioural assortment through direct reciprocity and beyond the perception of participants, and represents a self-organized pattern. Our results highlight the importance of the interaction between ecological context and selective pressures on cooperation.
自然界中合作的普遍性令人费解，因为合作者可能会被背叛者利用。最近的理论研究表明，如果动态网络定义了个体之间的相互作用，那么合作就会受到自然选择的青睐。为了解决这个问题，我们在静态和动态网络中的参与者之间进行了多个但独立的重复博弈，比较了合作行为。在后一种情况下，参与者可以在每次社交互动后断开他们的联系。正如预测的那样，我们发现动态网络中的合作水平更高。通过有偏见的链接断开（即与背叛者断开），参与者影响了他们的社交环境。我们表明，这种链接断开行为导致了大量的网络聚类，并且我们主要在这些聚类中发现了合作者。这种分类很显著，因为它是在直接互惠和参与者的感知之上发生的，并且代表了一种自组织模式。我们的结果强调了生态背景与合作选择压力之间相互作用的重要性。
