winning or losing an agonist encounter has a dramatic impact on future aggressive behavior. Winners are more likely to initiate attacks against unknown opponents, whereas losers are more circumspect and likely to retreat from unfamiliar conspecifics, adopting an opportunistic strategy, picking and choosing their fights. In the worst case scenario, animals socially subjugated by constant threat and attack from dominant conspecifics develop a submissive phenotype, showing little or no aggressive behavior, essentially eliminating themselves from the gene pool.
Randy J. Nelson, Biology of Aggression
biology