why are goldfish so dumb

Why Are Goldfish So Dumb?

One of the most popular fish in the world, goldfish actually have a reputation for being pretty dumb. Maybe it’s just because humans are so smart, we expect more from our fish. But is that reputation really true? In this article, I’ll give you all the reasons why aquarists consider goldfish to be dumb and why others might agree.

1- Goldfish’s Anatomy Limits The Ability To Learn

Goldfish have a very simple brain structure, which makes it harder for them to learn new things and remember what they’ve learned. Their brains are made up of fewer neurons than other animals, including humans, making it harder for them to process information.

Scientists haven’t yet been able to determine how many neurons goldfish and other creatures have in their brains. But we do know that humans have 100 billion neurons and that cats and dogs have an estimated 500 million neurons. So even though cats are considered one of the smartest animals on Earth, they still have fewer neurons than humans do.

2- Goldfish Take Forever To “Decide” Things

why are goldfish so dumb

Goldfish aren’t great at making decisions — or learning from their mistakes. For example, They don’t recognize themselves in mirrors or remember anything for longer than a few seconds.

Scientists aren’t exactly sure why goldfish have such short attention spans. But they do know that the fish’s brain is really small compared to its body size — only about one-tenth of a gram compared to its total weight of around 5 grams (0.18 oz).

In comparison, a chimp’s brain weighs about 1 percent of its body weight, and an elephant’s brain weighs about 5 percent of its body weight. So there’s just not much room for a lot of neurons in those tiny fish heads.

3- Goldfish Have Pretty Short Memory

Goldfish have pretty short memories, which means they can be easily distracted. In fact, they might not even recognize you if you haven’t fed them in a while.

“They’re not exactly the brightest bulbs in the tank,” said Dr. Chris Brown, a professor of biology at Brock University who has studied goldfish intelligence for over two decades.

Brown says that goldfish aren’t as intelligent as some other animals; for example, he says that parrots have about the same level of intelligence as a 2-year-old child. Goldfish have “the intelligence of a mosquito,” Brown told Live Science.

But why do goldfish have such limited mental faculties? It’s all about their memory capacity and learning ability.

Goldfish seem to have very poor memories compared with other species of fish and even compared with other types of animals, including humans. They are unable to remember things for long periods of time or even learn new behaviors unless they are exposed to them multiple times over several days or weeks, according to research by Brown and his colleagues published in 1995 in the journal Animal Behavior: An International Journal of Animal Behavior Society.

4- Goldfish Can’t Control Their Eyes

goldfish eyes

Goldfish can’t control their eyes. They’re constantly looking around, which might seem like a good thing but they can get easily distracted and disorientated by movement, so you’ll see them swim in circles all the time.

This is because goldfish have no eyelids, and so their eyes are always exposed to the outside world. This is why you’ll often see them swimming in circles without seeming to notice anything around them. They have to swim around with their eyes closed for a few seconds every now and then so that their eyes can rest – otherwise, they would never be able to stop staring at something!

Goldfish also don’t have very good hearing or sense of smell; this is why they don’t react when you call their name or sing songs to them (though they may perk up if they hear food being prepared).

5- Goldfish Can Only See Certain Colours

Because of the size of their eyes, goldfish are unable to see colors that are not red, blue, or green. This is because the lens in a goldfish’s eye is much larger than it should be for its body size.

6- Goldfish’s Brains Are Too Small

small brain goldfish

Goldfish have very small brains that can’t handle much learning or memory. That’s why they tend to be pretty predictable and do the same thing over and over again — like swimming in circles.

A goldfish who cannot learn any new behaviors or recall past ones (i.e., one who cannot learn that food comes from the top of an aquarium or that a reflection is not another fish).

7- Goldfish Can’t Concentrate For Long

Goldfish have a very short attention span and can’t concentrate for a long time. Due to this they don’t learn tricks easily and aren’t trained easily either. However, they do enjoy playing games like “swimming races” where you try to get them to swim through a hoop or paper tube that you hold underwater while your fish swims around trying to find the opening first!


A beautiful and easy pet is goldfish. But you should know how to take care of these little guys before you buy them. They are very smart, but they are not like dogs. They don’t need a lot of attention, just a little. You should keep in mind that their memory isn’t that long. So, you should give them something new practically every day or every week. Like, put a marble in their tank every day so that when they find it, they can go look for it the next day and have fun finding it again. Or you can do some other fun activity with your fish. And please don’t forget to change their water regularly and give them food too!