Effects of cohesiveness on inter-sexual dominance relationships and spatial structure among group-living virtual entities

Abstract

Since male primates are bigger and stronger than females, they are by default considered dominant. When in a cohesively grouping ape (but not in its loosely grouping relative), females often appear dominant to males, the static image of female weakness is maintained and female dominance is attributed to high, species-specific co-operation among several females against single males. In this paper, an individual-oriented model is used to produce a parsimonious alternative: female dominance over males may directly vary with group-cohesiveness without species-specific differences in co-operative tendencies among females. The model consists of a homogeneous world in which entities roam. Entities are so constructed as to have merely a tendency to group and perform dominance interactions. ‘Male’ entities (StrongTypes) are characterised by a higher initial dominance value and intensity of attack than ‘female’ entities (called WeakTypes). Dominance values change and evolve due to the self-reinforcing effects of winning and losing contests. In the model, more rank-overlap between both types arises from a stronger feedback between dominance and spatial structure in cohesive than in looser groupings. Biological implications of these phenomena and testable hypotheses for real animals are discussed.