We often think of humans as the smartest animals. While this may be true, however, it doesn’t mean we’re the only animals out there with intelligence. In fact, there are some wild animals out there with intelligence that rivals our own!
Animal research has shown that some animals live in complex social structures, are able to use tools, comprehend language, solve problems by working together in a team, and show self awareness.
Measuring the intelligence of animals can be difficult because there are so many indicators, which can lead to great debate amongst experts. What criteria really determines intelligence?
Some will argue the indicators are meaningless, and that it’s brain size overall or brain-to-body ratio that determines cognitive ability in animals. 1 2
We’ve reviewed studies to bring you our definitive list of our top 10 smartest animals on the planet.
10. Pigeon
Unfortunately, in today’s society, pigeons are viewed as pests, especially in urban environments. But despite inspiring the insult ‘bird brain’ pigeons are one of the smartest animals on the planet.
Pigeons are actually domesticated animals, and these rather plump birds were first trained to help with errands, such as delivering important messages, as well as racing.
As far as intelligence and cognitive behavior go, a study in 2023 by the University of Iowa showed they could not solve high-level complex tasks. However, they turned to trial and error and memory, which experts have equated to AI, that uses similar basic methodology to get results. 3
They’ve been shown to be able to keep their attention on multiple things at once, and they’re one of the very few species of animals who are able to identify and recognize themselves in mirrors after training behaviors. 4
9. Rat
Rats and dogs share more in common than just being adorable, furry pets. Like pigeons, rats are seen as pests and nuisances by many. However, when it comes to intelligence, the rat’s small body carries a big surprise.
Pet rats have been known to learn and respond to their name. They’re also capable of learning how to recognize commands and perform different tricks. With further training, rats are even smart enough to learn puzzles and mazes!
In some cognitive-learning tests performed by Ben Vermaercke and his colleagues at KU Leuven, rats performed equally well as humans in recognising ‘good’ and ‘bad’ patterns. 5
8. Octopus
Octopuses actually have more than one brain. While there is a central, true brain, they also have smaller brains in each of their eight arms. This allows for each arm to work independently of the other seven. As a result, octopuses have been observed completing multiple tasks at once.
In another experiment, an octopus worked out how to unscrew a container lid to retrieve food inside.
Octopus have also shown they are able to recognise humans and repsond positively towards friendly people, as shown in the film ‘My Octopus Teacher’ where a filmmaker forges an unusual friendship with an octopus living in a South African kelp forest.
The size of the brain is also an important factor in determining intelligence. As far as brain-to-body ratios go, the octopus has the largest brain out of any other invertebrates (animals without spines).
They even have larger brains than certain species of vertebrates! 6
7. African Gray Parrot
It takes a lot of intelligence to learn the language of a completely different species. As a result, the African gray parrot has rightfully earned its place among the smartest animals in the world.
It’s not just a language that the African gray parrot can share with humans, however. When we think about whether or not an animal is intelligent, we tend to compare them to how humans go about thinking and solving problems.
If we are to judge the African gray parrot by these standards, they rank up there with a child ranging from three to five years old.
In 2019, researchers discovered that the African grey parrot could pass the classic two-cup test, in which a reward is hidden in one cup, the subject is shown the empty cup, and those who successfully choose the other cup via elimination receive a reward. This was extended to more reliable three and four cup tests, which were also a success. 7
6. Elephant
Let’s address the elephant in the room: it can be difficult to determine just how intelligent an elephant is. While few scientists protest the elephant as one of the smartest animals in the world, it can be challenging to know exactly where they fall in a top-ten list.
Some feel like they’re as smart as chimpanzees, while others may think elephants are as smart as dolphins. Regardless of position on a list, however, there’s no doubt that the elephant is a genius animal. They grieve for lost family members, have been witnessed aiding other species when in distress (including humans), and they have the largest brains of any land mammal.
Elephants have shown a remarkable ability to use tools, such as using branches to swat flies or to scratch themselves. They have also used rocks to drop onto electric fences to break and bypass them without receiving a shock, and moved large cubes to stand on to reach treats. 8
They can also recognise themselves in a mirror, something that domestic cats and dogs often struggle with and will react too.
5. Pig
The animal coming in at number five for smartest animals may surprise some people: the pig!
Pigs are highly intelligent animals. They’re known to be smarter than most other animals, including dogs. However, they’re also smarter than three year old humans, which is an impressive feat!
They are thought to be the most intelligent of all domesticated animals, with greater trainability than any other species. Pot-bellied pigs are easy to potty train, foragers have trained pigs to find valuable truffle mushrooms, and pigs can understand human-prompted cues.
Not only that, but when it comes to problem solving, they can even out perform most species of primates. Studies have shown they can complete mazes, and in 2015 an ecologist recorded a family of pigs using sticks as tools to dig within their zoo enclosure. 9
4. Raven
You may have heard recently that ravens are entering their stone age. This is because these highly intelligent birds have learned to use rocks and other natural materials as tools to solve problems and achieve goals.
They have the ability to understand problems and find solutions, remember people and their faces, and even understand the concept of the future and are able to plan for it.
The winged wizards have been witnessed dropping rocks onto people to scare them away from climbing near to their nests. Ravens also excelled in a logic test whey they were required to pull string, and anchor it with its talon until food was in reach.
As adults, ravens and crows are considered to be as smart as a human child up to seven years old. 10
3. Chimpanzee
When you think of the smartest animals in the world, your mind probably goes to the chimpanzee first. While they certainly are intelligent, they’re not the smartest, however.
Chimpanzees are incredibly intelligent, mentally flexible animals. They’ve learned to craft and efficiently use different types of natural tools; they can communicate with one another. They’re even able to think critically to solve problems and count.
In a 2007 study, researchers administered the same cognitive test to adult chimps, adolescent chimps, and college students, which involved remembering where nine numbers on a touchscreen monitor were located after seeing the numbers on the screen for 650, 430 or 210 milliseconds.
Adult chimps and college students performed similarly, but adolescent chimps performed better, remembering the location of the numbers in the correct order with far greater accuracy. 11
2. Orangutan
Orangutans share over 97 percent of its DNA with humans. These highly intelligent animals have been found using tools in the wild and creating deep bonds with their young.
Orangutans have been observed using tools to help forage for food, cross rivers, make umbrellas from foilage to stay out of the rain, use leaves for toilet paper and even use leaves against their mouth to help amplify the noises they can make to intimidate rivals.
Various studies and experiments show that they cooperate with each other, play games and that an adult organutan had self awareness in a mirror test.
1. Dolphin
One of the smartest animals in the world is the dolphin. Many scientists consider dolphins to be the second smartest animal, following directly after humans.
Dolphins are second only to humans in brain-to-body size ratio, above all members of the highly intelligent primate family. They have shown many indicators of intellgence –
- Dolphins appear to be able to communicate well with each other, and scientists have found evidence that dolphins call each other by ‘name’, with a unique whistle for each member of a pod.
- They appear to show compassion, as they have been observed looking after the old, sick and injured in a pod.
- Dolphins have been trained to help rescue lost naval swimmers, and to locate underwater mines.
- There are stories of dolphins assisting surfers that have been attacked by sharks. In one infamous encounter, they drove off the Great White Shark, and formed a ring of protection around the injured surfer until he managed to get back to shore and safety.
- Female dolphins have been witnessed using sponges as a foraging tool, to protect their noses from sharp underwater objects in the coral and sea urchins.
- Tests have shown long-term social recognition and memory. In one test, led by University of Chicago animal behaviorist Jason Bruck, dolphins were able to recognise whistles played to them from old social partners they had been separated from 20 years earlier.
- Dolphins at the Institute for Marine Mammal Studies in Mississippi were rewarded with fish for picking up litter. One dolphin called Kelly strategically hid paper and broke off smaller fragments, knowing that will mean she earned more fish – showing future planning, and cunning! 12
- They are one of the only animals able to recognise themselves in the mirror. So far, only dolphins, great apes, killer whale, a single elephant, the Eurasian magpie, cleaner wrasse fish and some pigeons have passed the test. 13
Given that intelligence has been repeatedly linked to brain size, one measure to consider is the ‘encephalization quotient’ (known as ‘EQ’) which compares an animal’s brain mass to the brain mass predicted for an animal of its size.
Dolphins have the highest EQ of any animal, around 5.3, other than humans, who have an EQ of around 7.5. This means their brains are more than five times the size they are predicted to be. 14
Final Thoughts
So, these are our smartest animals in the world – that we could reliably estimate, based upon many different studies from researchers and experts.
There are so many indicators to for animals to be ‘smart’, and some species might be better at one thing than another, similar to humans. The smartest animal, really depends on the criteria.
However, all the clever animals listed above seem to show similar traits and indicators of being smart, which include self awareness, problem solving ability, language comprehension and altruism in their social structures.
Which do you think is the smartest animal of them all?
Fact Sources & References
- Osvaldo Cairό (2011), “External measures of cognition“, Frontiers in Human Neuroscience.
- Daniel Sol et al (2022), “Neuron numbers link innovativeness with both absolute and relative brain size in birds“, Nature Ecology & Evolution.
- University of Iowa (2023), “Can pigeons match wits with artificial intelligence?“, Science Daily.
- Macphail E. M. (1987), “The comparative psychology of intelligence“, Behavior Brain Science.
- The Harvard Business Review (2015), “Rats Can Be Smarter Than People“, Harvard Business Review.
- Lisa Hendry (2022), “Octopuses keep surprising us – here are eight examples how“, The Natural History Museum, London.
- Peter Reuell (2019), “Study shows parrots can pass classic test of intelligence“, The Harvard Gazette.
- Ferris Jabr (2014), “The Science Is In: Elephants Are Even Smarter Than We Realized“, Scientific American.
- Katherine Gallagher (2022), “How Smart Are Pigs?“, Tree Hugger.
- Corina J. Logan , Sarah A. Jelbert, Alexis J. Breen, Russell D. Gray, Alex H. Taylor (2014), “Modifications to the Aesop’s Fable Paradigm Change New Caledonian Crow Performances“, PLOS ONE.
- Rowan Hooper (2007), “Chimps outperform humans at memory task“, Nature.com
- Varley, Len (2012), “Deeper Water“, Balboa Press.
- Rachel Morrison & Diana Reiss (2018), “Precocious development of self-awareness in dolphins“, PLOS One.
- Ursula Dicke and Gerhard Roth (2016), “Neuronal factors determining high intelligence“, The Royal Society of Publishing.