Spatial Centrality of Dominants Without Positional Preference

In many group-living animals dominant individuals occupy the center of a group. This is generally thought to reflect a preference for locations, that provide optimal protection against predators. However, in this paper I will show that such spatial-structure also emerges among artificial entities that lack preference for any spatial location. The artificial entities dwell in a homogeneous world and are completely identical at the start of the simulation. They are gregarious and perform dominance interactions in which the effects of winning and losing are selfreinforcing. Varying essential parameters of the model revealed that: 1) Social-spatial patterns are stronger among entities that perceive each others rank directly compared to those that estimate rank of others based on personal experiences. 2) Stronger social-spatial patterns result when entities obligatory attack others than when attack-rate was negatively dependent on rank-distance. 3) Raising the intensity of attack increased the centrality of dominants for the Obligatory attack system, but weakened it for the Rank-Distance Decreasing attack system. Also, other social interaction patterns emerged, such as bidirectionality of aggression and a correlation between rank and frequency of attack. Such epiphenomena may underlie the variation of social-spatial patterns found in real animals.