Cooperation and Conflict in Segregated Populations

Abstract

Humans behavior often varies depending on the opponent’s group membership, with both positive consequences (e.g., cooperation or mutual help) and negative ones (e.g., stereotyping, oppression, or even genocide). An influential model developed by Hammond and Axelrod (HA) highlighted the emergence of macrolevel “ethnocentric cooperation” from the aggregation of microlevel interactions based on arbitrary tags signaling group membership. We extended this model to include a wider set of agents’ behaviors including the possibility of harming others. This allowed to check whether and under which conditions xenophobia can emerge beside or in alternative to ethnocentric cooperation. The model was compared to Swedish data documenting social unrest and proxies of cooperative behaviors at the municipal level. The validation results supported the model predictions on conflict but not the ones on cooperation, casting doubts on HA’s original argument.

Evolution of cooperation in multi-agent systems with time-varying tags, multiple strategies, and heterogeneous invasion dynamics

“…This research direction could further facilitate a more complete understanding of intergroup disharmony [62] and conflict [33], which can significantly and sometimes even irreversibly impede cooperative behavior at a multitude of scales [63]. In analogy to scale misperception phenomena in socio-economic systems [64], it also needs to be acknowledged in future models that timescales of interactions among different populations as well as the underlying environmental cycles may not coincide with the timescale of decisions made about these populations, but may instead require strategic periodic behaviors that could play decisive roles in the management and prevention of collective conflict phenomena [65].…”

“…To address these realistic aspects, models of the evolution of tag-mediated cooperation [21,24,25,26,27,28,29,30,31,32,33,34] have investigated the emergence of generosity in phenotypically diverse societies of artificial agents that were able to employ more than two pure strategies, and immigration of new agents in these models has often been considered as a distinct stage in the evolutionary process. One prominent example is the seminal work of Hammond and Axelrod (HA) [21], addressing the ingroup-biased ethnocentric cooperation emerging in a phenotypically diverse population subject to immigration dynamics.…”