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Learn more »Goldfish have a reputation for only having a short memory, limited cognitive abilities, and no problem-solving skills, which has led many to believe that goldfish aren’t very smart. However, various scientific evidence research has proved otherwise.
Although goldfish are not considered the smartest fish or animals in the world, they are still considered intelligent.
It’s easy for fish lovers to say that their pets are smart, which is why looking at this from a scientific point of view can give us the most accurate answer.
Goldfish Intelligence
These domesticated members of the carp family are deemed to be dumb and even disposable creatures that can’t feel pain or emotions and lack cognitive abilities. This is because they are often compared to our furry friends with whom we have had more time to study and interact.
When it comes to understanding intelligence in aquatic animals like goldfish, it is crucial to understand that their intelligence is not easily comparable to humans, dogs, or even aquatic mammals like dolphins.
Since goldfish live in an entirely different environment than us, they don’t show intelligence in the same way we would. A goldfish won’t be able to solve a math problem or design the latest microwavable oven, but they are intelligent in their own way. Goldfish have been reported to have good memories and recognize faces, sounds, and vibrations that they associated with a positive or negative experience in the past, according to science.
Goldfish can also apply basic problem-solving skills necessary for survival or locate a piece of food lodged behind the filter. The popular saying that goldfish have a 2- to 5-second memory is false, and it has likely been used to justify keeping goldfish in less-than-ideal conditions, such as small bowls.
Many people wouldn’t feel good about putting an intelligent and sentient animal in unideal conditions, which is why the misconception that goldfish are not intelligent can be so harmful to them.

What Science Says About Fish Cognition & Intelligence
According to Professor Culum Brown, a fish expert at Macquarie University, “fish are more intelligent than we give them credit for while having a range of behaviors that suggests they are intelligent and have a consciousness.”1 Brown’s paper explained how fish have a good memory, remembering who feeds them, the time that they were given food, and the place where the food is likely to appear.
Brown also notes how a fish’s level of intelligence will affect the welfare the animal receives. Since many fish are disregarded as unintelligent animals that cannot feel pain or suffering, we seem to put the fish through unpleasant experiences that can cause fear and pain.
Experiments & Studies
Goldfish are used as a common model when it comes to studying memory in fish. Brown also acknowledges that goldfish have good problem-solving skills that allow them to remember how to repeat tasks they were taught months ago. This includes experiments where goldfish were taught to escape from nets or mazes, even if they were taught it weeks or months ago.
Other experiments include ones in which goldfish push a certain color on a button that gives them food and ignore the color that doesn’t once they learn which one gives them food. By feeding your goldfish from the top of the aquarium for a few days, goldfish associate the top of the aquarium with food, swim around the top, wait for food, and even get excited when the person who feeds them comes near the aquarium.
If you were to feed your goldfish a sinking food that falls onto the substrate, goldfish will spend less time at the surface and more time sifting through the substrate waiting for food. Some owners also claim that their goldfish can recognize them from other people, especially if they associate you with something positive like food.
Food motivation is common in many intelligent and complex animals, such as dogs and rodents.

Spatial Cognition & Remembrance
If goldfish weren’t intelligent, they wouldn’t have the necessary cognitive abilities to problem-solve or remember things that affect or benefit them. Goldfish may also avoid situations that negatively affect them by becoming fearful and defensive.
Scientists also found that fish use spatial cognition to form a cognitive map. Fish do not have a hippocampus, which is responsible for memory in humans. The lack of cortex and hippocampus was thought to lead to goldfish’s poor memory, but countless tests have proven this false.
Spatial cognition allows goldfish to perceive and utilize various ways of thinking, which benefits their survival and helps them complete daily tasks. Goldfish may even recognize other fish they have encountered in their lifetime and recognize people’s faces and hands that they associate with something positive.
Therefore, goldfish and fish generally can problem-solve, form memories, and react to pain, making them intelligent and sentient beings.

Intelligence & Perceiving Pain in Goldfish
When we think of unintelligent animals, we might think they are incapable of feeling pain or unpleasant emotions like humans and animals can. From a scientific viewpoint, fish have the right nerves and pain receptors to feel and react to pain, just like humans and many other animals can.
Aside from the emotional pain that goldfish feel, they can also physically feel pain because they have nerves throughout their body. Like all fish, the goldfish has a central nervous system (spinal cord and brain) and a peripheral nervous system, which has all the nerves that branch out from the spinal cord and brain. The latter has pain receptors that allow the body to respond to pain much as a human would.
Humans have central and peripheral nervous systems, which are believed to allow us to react to our environment, including things that cause us pain. However, fish seem to lack certain parts of the brain that humans use for processing pain.
Joseph Garner, an assistant professor of animal sciences, and Janicke Nordgreen, a doctoral student of veterinary science, helped detail a paper from a test on thermonociception in fish and their ability to perceive pain.
The test was carried out by injecting half of the goldfish with saline and the other half with morphine, which blocks pain signals in the body. Then, they exposed the goldfish to a higher temperature to see their reaction to the pain.
Both the goldfish injected with saline and morphine had a behavioral response to the pain by wiggling around in the water and generally being uncomfortable in the hotter temperature. Later, after the study was conducted and the fish were placed in their home aquariums, the fish that were given saline acted fearfully and defensively, whereas the goldfish given morphine acted normally.
This led Garner to believe that it is due to the morphine blocking the painful feeling during the test but not the goldfish’s behavioral response.

Opinions to the Contrary
Conversely, several researchers have argued that these experiments don’t necessarily prove intelligence, but rather that the fish’s behavior is a natural response to environmental stimuli and should be considered nociception, the ability to respond appropriately to a stimulus.
Furthermore, although social cognition has been studied in fish, the experiments have limitations and cannot definitively prove the presence of emotions in fish (including goldfish). A detailed analysis on the emotions of fish concluded that there isn’t enough evidence to say that fish feel emotions.
Finally, it is not quite clear if research on one fish species regarding its intelligence, IQ, or emotional perception can also apply to goldfish. While some fish might possess these traits, it’s not guaranteed that all fish possess them.
Conclusion
Goldfish have been proven to have intelligence comparable to that of many vertebrates. They even respond to pain and stressful situations, have a decent memory, and can apply problem-solving skills.
Of course, a goldfish in a small bowl with little to do won’t be able to display natural behaviors that allow us to perceive them as sentient and intelligent animals. That is why animal lovers and researchers are working hard to prove that fish are deserving of proper welfare and ethics because they are intelligent and sentient beings like humans, dogs, and many other familiar animals.
However, the jury is still out on just how intelligent goldfish are and whether they can feel emotions. Researchers also point out that many factors attributed to “intelligence” might just be normal physiological responses and survival mechanisms.
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