Relative opinion similarity leads to the emergence of large clusters in opinion formation models

This study considers a variant of the bounded confidence opinion formation model wherein the probability of opinion assimilation is dependent on the relative similarity of opinions. Agents are located on a social network and decide whether or not they adopt the opinion of one of the neighbors (called a role agent). Opinion assimilation is more (less) likely to occur when the distance from the opinion of the role agent is smaller (larger) than the average opinion distance from other neighbors. Thus, assimilation probability is reliant not only on opinion similarity with the role agent considered in conventional models but also on relative similarity that considers other neighbors. The simulation results demonstrate that the size of the largest opinion cluster increased when relative similarity has a large influence on assimilation probability. The size of the threshold parameter of the bounded confidence model displays inverse-U relationships with the largest cluster size. The findings imply that consideration of relative opinion similarity, which has been observed in recent empirical studies, prevents polarization into small opinion clusters.