Fish Cognition and Behavioral Complexity

Fish cognitive abilities are far more sophisticated than commonly assumed, with implications for how we should regard their welfare and treatment.

Key Facts

Cleaner wrasse fish pass a modified version of the mirror self-recognition test
Fish demonstrate social learning, watching and copying the behavior of experienced fish
Archerfish spit water with impressive accuracy to knock insects from overhanging branches
Some fish species use tools including using anvil rocks to open shellfish
Cichlid fish show personality differences that persist across different situations and over time

Welfare Considerations

The cognitive lives of fish have been profoundly underestimated. Decades of research have progressively revealed sophisticated abilities including social learning, tool use, problem solving, and individual personality differences. Cleaner wrasse fish show behavior in the mirror test that suggests some form of body awareness. Fish learn from watching others and can pass learned information through generations. These cognitive abilities matter for welfare: more sophisticated cognition generally implies greater capacity for complex experiences including suffering and potentially positive states. The common assumption that fish are simple reflex animals has been thoroughly overturned by contemporary behavioral research.

What You Can Do

Learn about fish cognition to build evidence-based appreciation for their welfare needs
Share fish cognition research with others who dismiss fish welfare concerns
Support research into fish cognitive abilities and their welfare implications
Advocate for welfare standards that account for fish cognitive sophistication
Reduce or eliminate fish consumption from operations with poor welfare standards