Consensus costs and conflict in a collective movement

Abstract

Aggregation, whether it be in natural or artificial systems, provides numerous benefits to both the individual and the group. However, aggregation has costs and frequently involves inter-individual conflict. Although conflicts in natural systems is understood to be at times beneficial, as well as detrimental, conflict in artificial systems, such as a team of robots, is frequently viewed as inhibiting consensus and, therefore, success. This is particularly the case in large-scale aggregations where ensuring consensus is especially challenging. In response, mechanisms are often integrated into the group's control systems to minimize, or even eliminate, conflicts of interest. As a result, the potential benefits of losing consensus, such as increased diversity and reduced consensus costs, are not available. Using a biologically-based collective movement model, we demonstrate that not enforcing consensus and allowing conflict to evolve as agents make decisions results in a system in which agents meet their own needs, thus minimizing consensus costs, while still maintaining group cohesion when possible. Simulations predict that conflict balances consensus costs with individual preferences such that both individual and group goals are met.

Coordination and consensus: the role of compromisers in Tibetan macaques

“…In group movements, a consensus process is often known as when “members of a group choose between 2 or more mutually exclusive actions with the specific aim of reaching a consensus” ( Conradt and Roper 2005 , p. 449). All group members usually have opportunities to affect the decision-making process in large collectives, but they play disproportionate roles ( Solum et al 2014 ; Ward et al 2018 ). For example, bold homing pigeons Columba livia show a high propensity to lead a group movement, and they can arrive at safe locations more quickly than less exploratory individuals ( Sasaki et al 2018 ).…”

“…Further, subordinate chacma baboons Papio ursinus usually accept despotic decisions, even where this forgoes their optimal activity options ( King et al 2008 ). In general, a conflict of interest is regarded as a disadvantageous occurrence that raises obstacles to collective decision-making ( Solum et al 2014 ). Therefore, social animals have taken some actions to reduce conflicts within groups.…”

“…Conflicts can be resolved effectively through compromise, especially in cases of “when” and “where” decisions ( Solum et al 2014 ). Under such situations, some members must strike a balance between group and individual benefits by decreasing their optimal choices about direction and timing, thus they can be considered as compromisers.…”