Group fusion: the impact of winner, loser, and bystander effects on hierarchy formation in large groups

We present the results of a series of computer simulations thatexamined the impact of winner, loser, and bystander effectson hierarchy formation in fused groups. These effects and theirimplications for hierarchy structure and aggressive interactionswere first examined in small four-member groups. Subsequentto this, the two small groups were fused into a single largergroup. Further interactions took place in this fused group,generating a new hierarchy. Our models demonstrate clearly thatwinner, loser, and bystander effects strongly influence boththe structure and types of interactions that emerge from thefusion of smaller groups. Four conditions produced results inwhich the same general patterns were uncovered in pre- and postfusiongroups: (1) winner effects alone, (2) bystander loser effectsalone, (3) winner and bystander winner effects operating simultaneously,and (4) all four effects in play simultaneously. Outside thisparameter space, hierarchy structure and the nature of aggressiveinteractions differed in pre- and postfusion groups. When onlyloser effects were in play, one of the two clear alphas fromthe prefused groups dropped in rank in the eight-member fusedgroup. When bystander winner effects were in play, it was difficultto rank any of the eight individuals in the fused group, andplayers interacted almost exclusively with those that were notin their original four-member group. When loser and bystanderloser effects operated simultaneously, two top-ranking individualsemerged in the fused groups, but the relative rank of the otherplayers was difficult to assign.