[论文解读] Can extremism guarantee pluralism?

Floriana Gargiulo, Alberto Mazzoni|ArXiv.org|Mar 27, 2008

Opinion Dynamics and Social Influence参考文献 33被引用 5

一句话总结

本文提出了一种社会网络中意见动态的模型，其中个体具有连续分布的意见，并在容忍不同观点的程度上各不相同。通过基于个体容忍阈值和网络隔离的互动建模，研究发现，只有当极端主义群体仍与更广泛的社会保持连接时，多元主义——即持续存在的意见多样性——才会出现，而非在它们孤立或所有互动均无限制的情况下。

ABSTRACT

Many models have been proposed to explain opinion formation in groups of individuals; most of these models study opinion propagation as the interaction between nodes/agents in a social network. Opinion formation is a complex process and a realistic model should also take into account the important feedbacks that the opinions of the agents have on the structure of the social networks and on the characteristics of the opinion dynamics. In this paper we will show that associating to different agents different kinds of interconnections and different interacting behaviours can lead to interesting scenarios, like the coexistence of several opinion clusters, namely pluralism. In our model agents have opinions uniformly and continuously distributed between two extremes. The social network is formed through a social aggregation mechanism including the segregation process of the extremists that results in many real communities. We show how this process affects the opinion dynamics in the whole society. In the opinion evolution we consider the different predisposition of single individuals to interact and to exchange opinion with each other; we associate to each individual a different tolerance threshold, depending on its own opinion: extremists are less willing to interact with individuals with strongly different opinions and to change significantly their ideas. A general result is obtained: when there is no interaction restriction, the opinion always converges to uniformity, but the same is happening whenever a strong segregation process of the extremists occurs. Only when extremists are forming clusters but these clusters keep interacting with the rest of the society, the survival of a wide opinion range is guaranteed.

研究动机与目标

• 研究个体容忍阈值如何影响意见动态与社会网络结构的共同演化。
• 探讨在具有异质互动行为的社会中，极端意见是否能与多元主义共存。
• 分析网络隔离与连通性在维持意见多样性方面的作用。
• 确定在何种条件下意见会收敛为统一，而非持续存在多个意见集群。
• 使用社会聚合机制，对意见形成与网络拓扑之间的反馈进行建模。

提出的方法

• 为代理分配从一个极端到另一个极端的连续意见，代表观点谱系。
• 每个代理具有独特的容忍阈值，决定其与持有不同意见者互动的意愿。
• 极端主义者容忍度较低，通过社会聚合机制倾向于形成隔离的集群。
• 互动与意见更新基于意见空间中的接近程度，并按容忍阈值加权。
• 网络结构随时间动态演化，代理根据意见相似性和容忍度形成或切断连接。
• 模拟追踪意见随时间的演化，测量收敛性、集群形成以及意见多样性的持久性。

实验结果

研究问题

• RQ1 在容忍度水平异质的社会网络中，意见多样性在何种条件下能够持续存在？
• RQ2 极端主义者的隔离如何影响整体意见动态以及向共识的收敛？
• RQ3 极端主义群体与社会其余部分之间的互联性在维持多元主义方面起到什么作用？
• RQ4 无限制的互动是否总是导致意见统一，还是多元主义仍可能产生？
• RQ5 意见形成与网络结构之间的反馈如何影响多个意见集群的存续？

主要发现

• 当所有代理在无限制下自由互动时，意见动态总会收敛为统一，导致多元主义消失。
• 当极端主义者被隔离并形成隔离集群时，意见统一仍会浮现，表明不存在多元主义。
• 只有当极端主义集群与更广泛社会保持一定程度的互动时，多元主义才能被维持。
• 广泛意见的存续关键取决于极端与温和意见集群之间的连通性。
• 该模型表明，极端主义并不保证多元主义；相反，是极端与温和代理之间的互动维系了多样性。
• 意见与网络结构的共同演化导致了稳定的意见集群，尤其在容忍阈值异质时更为明显。