个体行为与社会环境耦合演化的舆论生成模型

Opinion formation model with co-evolution of individual behavior and social environment

社会舆论的形成是个体行为及其关联与社会环境影响共同作用的结果.在受到环境因素影响的同时,个体行为也反过来影响社会环境,从而呈现出耦合演化的特点.本文在Ising模型的基础上,建立了一个包含社会张力累积和消解过程的舆论形成模型,研究了个体行为和社会环境的耦合演化行为.利用朗道的平均场理论,重点分析了在不同舆论疏解系数下系统演化的定态解及其稳定性,以及系统定态解随参数变化的分支行为.同时使用计算机模拟方法对平均场理论的结果进行了印证.研究结果表明,将系统与环境的耦合演化机制加入Ising模型后,系统会展现出一定的自组织特性.当疏解系数较小时,系统会出现不同程度上的整体一致舆论,产生宏观有序状态;当疏解系数较大时,系统则稳定在无序状态.同时,存在一个临界参数,使系统从任何初始状态出发均自发演化到临界的分支点状态.

Entering the information era,the formation of public opinion is largely associated with the complex system constructed by the Internet,thereby possessing new characteristics.The formation of public opinion is the result of the interaction of individual behavior with social environment.In reality,the environmental factor and the individual behavior are usually related to each other and co-evolve with time.Based on the Ising model,in this paper established is an opinion formation model that includes the process of the accumulation and digestion of the social tension.In the model,a parameter named effective dissolving factor c is designed to represent the extent of the interaction between the system and the social environment.A two-dimensional dynamical system is involved in the model to describe the dynamics of individual behavior and social tension.The co-evolution behavior of the system is studied.Based on the Landau mean field theory,the stationary states of the dynamical system under different parameter values,i.e.the value of effective dissolving factor c,their stability and bifurcation of the system,are analyzed.Finally,the computer simulation method is used to verify the results.The research shows that with the co-evolution mechanism of the system,our model exhibits certain selforganization characteristics.When the effective dissolving factor c is smaller than the threshold value,the system will reach final consensus opinion,resulting in a macroscopically ordered state.Otherwise,when the dissolving factor c exceeds a threshold value,the system is stable in the disordered state.It is interesting to find that there is such a critical value of the parameter that it leads the system to be self-organized into a critical state from any initial state.The future detailed investigation on the criticality of the co-evolving system is also suggested,such as testing whether the system has evolved into the critical state according to the finite-sized scaling theory and calculating the critical exponent of the system.In addition,in this paper provided is a new perspective to tackle practical problems in public opinion.Based on the mechanism of the formation of public opinion revealed by our model,researchers are encouraged to conduct studies on how to monitor the state of public opinion more precisely and to predict the tipping point of the system evolution.