Goldfish have a three-second memory. Bowl life is a small kindness, because the fish has forgotten the bowl by the time it gets back to the same wall. Every kid with a goldfish was told this. It was the standard rebuttal when anyone complained about keeping a fish in a 30cm bowl. Three-second memory, no concept of time, perfectly happy. The argument was airtight. The bowl was on the desk. The fish, presumably, was content.
Goldfish have memory measured in months. Multiple studies, including a particularly accessible 2003 one out of Plymouth University in which a 15-year-old student trained goldfish to push a lever for food, demonstrated that goldfish can learn associations, navigate mazes, recognise individual humans, and retain learned behaviours over weeks and months. They have been trained to perform on a schedule, to discriminate between musical genres (yes, really), and in classical conditioning paradigms to anticipate feeding times. The three-second number has no scientific source and appears to have been coined as a rationalisation by people selling small bowls. Goldfish in 30cm bowls are not happy. They are stunted, oxygen-starved, and live around a fifth of their natural lifespan (proper conditions: 10-15 years, sometimes more). The myth was useful for the pet industry. It was always wrong about the animal. The fish remembers. It remembers the wall, the food schedule, the human, and probably the bowl. It just can't tell you about it.
Reception
Sources
- Animal Cognition: Goldfish Memory Study PRIMARY
- LiveScience: Goldfish Facts REFERENCE