Cognitive dissonance

Biological Parallel

Cleaner wrasse fish experience a form of cognitive dissonance when feeding on client fish. They prefer eating nutritious client mucus over parasite removal, but parasites are what clients reward with repeat visits. Brain imaging shows heightened activity in the wrasse's forebrain when resisting the temptation to cheat—they must continuously reconcile the conflict between immediate preference (mucus) and long-term benefit (client retention). Fish that fail to resolve this dissonance lose clients and starve.