How do winning and losing fights contribute to dominance hierarchies in animals?

In animal social structures, winning and losing fights are fundamental to establishing and maintaining a dominance hierarchy. These hierarchies function as a system of relationships where subordinate individuals consistently defer to dominant ones, often replacing overt, dangerous conflict with ritualized displays or postures to minimize the risk of injury and energy expenditure.123

The process typically unfolds as follows:

• Establishing Rank: Through initial aggressive interactions, individuals assess their relative strength. Victors adopt dominant postures—such as an upright stance in wolves or raised legs in crustaceans—while losers adopt submissive postures to avoid further attack.24
• Neuroendocrine Modulation: Fighting experience alters brain chemistry, reinforcing social status. In many species, dominant individuals and subordinates exhibit different levels of neurotransmitters like serotonin, which modulate the willingness to engage in future aggression.4
• Cost-Benefit Dynamics: Subordinates often accept their low status because the high costs of challenging a stronger rival—such as the risk of injury or death—outweigh the potential benefits of winning. Conversely, dominant animals must frequently defend their status, which is energetically costly and can lead to physical decline over time.3

Ultimately, these hierarchies provide a stable social structure that allows groups to coexist with reduced levels of direct conflict.12