Social Influence and the Collective Dynamics of Opinion Formation

Abstract

Social influence is the process by which individuals adapt their opinion, revise their beliefs, or change their behavior as a result of social interactions with other people. In our strongly interconnected society, social influence plays a prominent role in many self-organized phenomena such as herding in cultural markets, the spread of ideas and innovations, and the amplification of fears during epidemics. Yet, the mechanisms of opinion formation remain poorly understood, and existing physics-based models lack systematic empirical validation. Here, we report two controlled experiments showing how participants answering factual questions revise their initial judgments after being exposed to the opinion and confidence level of others. Based on the observation of 59 experimental subjects exposed to peer-opinion for 15 different items, we draw an influence map that describes the strength of peer influence during interactions. A simple process model derived from our observations demonstrates how opinions in a group of interacting people can converge or split over repeated interactions. In particular, we identify two major attractors of opinion: (i) the expert effect, induced by the presence of a highly confident individual in the group, and (ii) the majority effect, caused by the presence of a critical mass of laypeople sharing similar opinions. Additional simulations reveal the existence of a tipping point at which one attractor will dominate over the other, driving collective opinion in a given direction. These findings have implications for understanding the mechanisms of public opinion formation and managing conflicting situations in which self-confident and better informed minorities challenge the views of a large uninformed majority.

Network dynamics of social influence in the wisdom of crowds

“…Consistent with previous work, our theoretical results predict that centralized networks will exhibit a bias toward the beliefs of central individuals. However, in contrast to prior work showing that social influence undermines group accuracy (11)(12)(13)(14)(15)(16)(17)(18), we predict that social influence in decentralized networks will improve the accuracy of the group median (SI Appendix). Moreover, we also predict that social influence can produce systematic improvements in the accuracy of the group mean if the individual revision process is not i.i.d., but is correlated with individual accuracy.…”

“…Unlike research on social coordination (28,32,33) and group problem-solving (34-36), our study does not consider situations where social interaction is necessary for groups to achieve a collective outcome. Instead, we identify how the network dynamics of social influence can affect collective estimation tasks in situations where social influence has been predicted to have a negative effect on the quality of group judgments (2,(11)(12)(13)(14)(15)(16)(17)(18). Our finding that groups have the ability to generate accurate estimates, even in the presence of social influence, has useful implications for the design of several kinds of collective decision processes.…”

“…When social influence leads to correlated errors, both independence and diversity are reduced, which has been argued to compromise the reliability of the group judgment (9,(11)(12)(13)(14)(15)(16)(17)(18). In direct contrast with these results, however, theoretical models of social learning (19)(20)(21) have suggested that the effects of social influence on collective decisions vary based on the structure of the interaction network, predicting that, under the right conditions, social learning can lead a group's median judgment to improve (20)(21)(22)(23)(24).…”

Consensus and Disagreement: The Role of Quantized Behaviors in Opinion Dynamics

“…Introduction. A fundamental assumption in opinion dynamics is that one's opinion is attracted by others', as supported by a substantial literature [31,33,15,37]. If we assume that the opinion of each individual i is described by a variable x i ∈ R, we can describe this attraction by a linear law and thus describe the evolution of the opinions by the following set of differential equations:…”

The Strength of Weak Leaders - An Experiment on Social Influence and Social Learning in Teams

“…Similarly, there were two questions about the share of water in certain vegetables. Questions related to diverse topics and each question was already tested in previous experiments Rauhut and Lorenz, 2011;Moussaïd et al, 2013).…”