Group size and relative competitive ability: geometric progressions as a conceptual tool

Contrary to the assumptions of many previous theoretical models, group size has recently been shown in experiments to have an effect on the relative (as well as absolute) competitive abilities of group members. Here we introduce a novel and effective mathematical tool for describing how relative competitive ability will change for any two specified individuals within a group as group size changes. We show that there is no simple general rule for describing how relative competitive ability will change with group size. A subsequent empirical test of the model helps to illustrate that very specific knowledge of the system under study is needed in order to produce robust predictions. Received: 23 December 1998 / Received in revised form: 26 July 1999 / Accepted: 2 October 1999