We study the mechanisms by which group-living entities make decisions. Understand how decisions are made, determine who has influence and identify the mechanisms by which information and preferences are integrated, poses a fundamental challenge in several fields. We investigate the decision-making process when it happens in a decentralized way. However, in many situations, the leadership of one or more individuals may be beneficial to the entire group. For this reason, we also explore the effect of leadership in the organization and in the formation of opinion in the presence of leaders, but in the absence of complex signaling mechanisms, that is, when group members cannot establish who has or does not have relevant information. We also test our main hypothesis against experimental results obtained from minirobot assemblies and fish schools in the laboratory.
