Self Organization and social complexity in primates

Mathematical Biology

03 October 14:00 - 14:45

Charlotte Hemelrijk - University of Groningen

The structuring influence of dominance interactions and spatial proximity on complex social systems in animals is increasingly acknowledged. Here I show with a computational model (DomWorld, and extensions) that many complex patterns of social interaction emerge (that are usually attributed to sophisticated cognition) if individuals in the model merely group with, compete with others and groom them if they are anxious to lose a fight. For example, coalitionary support of all types (conservative, bridging and revolutionary) emerges, as well as its reciprocation, and reciprocation of opposition. Further, grooming is reciprocated, exchanged for support, and shown in patterns of post-conflict affiliation, including those of ‘reconciliation’ and ‘consolation’, with similar differences between species with a tolerant and intolerant dominance style as in empirical data. These patterns emerge without the usual assumptions of record-keeping, a motivation to help others or to reconcile and without any knowledge of social relationships. They emerge mainly because dominance interactions create a spatio-social structure that influences the occurrence of other social behavior in unexpected ways. When competitive interactions in the model are based on the winner-loser effect, i.e. after losing a fight the chance to lose the next fight is increased, inter-sexual dominance relations appear to depend on sex ratio and intensity of aggression. Females become more dominant over males, the fiercer the aggression among group members is, and, in groups with intense aggression, the higher the percentage of males in the group is. New patterns in the model have been confirmed by empirical data. For instance, more female dominance for a higher proportion of males in a group has been confirmed for fish, several taxa of primates and humans, and the ‘exchange’ of opposition for being groomed has been shown in more intolerant macaques. These models can therefore help us to develop new hypotheses about the mechanisms underlying social complexity.
Mats Gyllenberg
University of Helsinki
Torbjörn Lundh
Chalmers/University of Gothenburg
Philip Maini
University of Oxford
Roeland Merks
Universiteit Leiden
Mathisca de Gunst
Vrije Universiteit Amsterdam


Roeland Merks


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