The role of communication structure in consensus decision-making in human and animal groups

Imagine a group of several individuals with strong opinions that is required to collaborate. To this end, the group should find a consensus. Not an easy task, is it? How dynamic networked groups achieve a consensus is the research question explored by CASCB researchers Nico Gradwohl, Ariana Strandburg-Peshkin, and Helge Giese within their project The role of communication structure in consensus decision-making in human and animal groups. “Firstly, we ask how network structure and individual preferences interact, also with regard to outnumbering a global majority based on local interactions. Secondly, which role individual control over the interaction partners in the network plays. And thirdly, how other factors, such as cost of communication or individual differences, affect the strategies that individuals rely on.”

To find answers to these questions, biologist Ariana Strandburg-Peshkin and psychologists Nico Gradwohl and Helge Giese are using a combination of online experiments and agent-based models, thereby comparing competing hypotheses and exploring processes.
In their online group experiments, participants are incentivized to arrive at a consensus on two alternative options, while each individual can earn additional personal benefits for one of the consensus outcomes. As a further complication, they can only selectively communicate and coordinate with single group members to find a group-wide solution. So who will give up their stance? And why? “Content-wise, the most exciting aspect of this project is learning more about basic forms of communication and low-level interaction processes in consensus formation, which is inarguably a challenge for groups and societies alike,” say the researchers.

Communication structure has major relevance

Already after the test phase, which was recently completed, they are surprised by the results, as Gradwohl says: “Originally, we were mainly interested in situations in which individuals determine to whom they send information about their preferred course of action. However, we quickly realized that the decision about from whom one receives information can also be extremely important and has significant implications for the strategies that individuals should rely on when they select interaction partners.”

They also gain new insights into the topic of echo chambers. Echo chambers represent an environment where a person only encounters information or opinions that reflect and reinforce their own. This was recently raised as an important issue in the formation of political opinion. "Our results from an online experiment show that people who try to find consensus largely avoid others who agree and thus avert the formation of echo chambers," adds Gradwohl.