The Microsoft Research-University of Trento Centre for Computational and Systems Biology, Povo (Trento) 38123, Italy.
J Theor Biol. 2012 Apr 21;299:126-38. doi: 10.1016/j.jtbi.2011.09.005. Epub 2011 Sep 22.
Social, biological and economic networks grow and decline with occasional fragmentation and re-formation, often explained in terms of external perturbations. We show that these phenomena can be a direct consequence of simple imitation and internal conflicts between 'cooperators' and 'defectors'. We employ a game-theoretic model of dynamic network formation where successful individuals are more likely to be imitated by newcomers who adopt their strategies and copy their social network. We find that, despite using the same mechanism, cooperators promote well-connected highly prosperous networks and defectors cause the network to fragment and lose its prosperity; defectors are unable to maintain the highly connected networks they invade. Once the network is fragmented it can be reconstructed by a new invasion of cooperators, leading to the cycle of formation and fragmentation seen, for example, in bacterial communities and socio-economic networks. In this endless struggle between cooperators and defectors we observe that cooperation leads to prosperity, but prosperity is associated with instability. Cooperation is prosperous when the network has frequent formation and fragmentation.
社会、生物和经济网络会随着偶尔的分裂和重组而增长和衰落，这些现象通常可以用外部干扰来解释。我们表明，这些现象可能是简单模仿和“合作者”与“背叛者”之间内部冲突的直接结果。我们采用了一种动态网络形成的博弈论模型，其中成功的个体更有可能被新加入者模仿，新加入者采用他们的策略并复制他们的社交网络。我们发现，尽管使用的是相同的机制，但合作者促进了连接良好、繁荣的网络，而背叛者则导致网络分裂并失去繁荣；背叛者无法维持他们入侵的高度连接网络。一旦网络分裂，它可以通过新的合作者入侵来重建，导致在细菌群落和社会经济网络中看到的形成和分裂的循环。在合作者和背叛者之间的这场无休止的斗争中，我们观察到合作导致繁荣，但繁荣与不稳定性有关。当网络频繁形成和分裂时，合作是繁荣的。
