Watching fights raises fish hormone levels - cichlid fish wrestling for dominance induce an androgen surge in male spectators

Social interactions among the animals in a group affect their subsequent behaviour, manifesting as dominance hierarchies or territoriality, for example, and meaning that behaviour is adjusted to social context. These interactions are thought to be modulated by androgens, allowing the agonistic motivation of individuals to adjust to changes in their social environment; androgen production is itself determined by sexual status and by social contacts among conspecifics