The findings from years of psychological researches have led us to believe that humans are the most intelligent species on the earth. We possess a larger prefrontal cortex (a brain section associated with cognition) than any other animal species and have a large brain-to-body ratio overall.
Moreover, traits such as episodic memory, mental time travel, and a more enhanced emotional quotient indeed make humans stand apart from the rest. But we are certainly not the only intelligent creature out there. In fact, the animal kingdom is filled with creatures excelling in certain kinds of cognitive skills that are lacking in humans.
Determining the mental capacities of animals is more challenging than that of humans since it requires methods other than verbal expressions. The use of tools, social learning, responses to a new habitat, self-recognition, and brain size are some of the criteria used for measuring animal intelligence.
Here, we have compiled a list of the smartest animals, from crows to dolphins, and why we think they are the ones. The list is not in any order.
A group of chimpanzees in Uganda | USAID Africa
Chimpanzees, our closest living relatives, have many things in common with humans. Like us, the intelligence and other cognitive traits in chimps are passed down genetically. According to the Chimpanzee Genome Project, about 30 percent of encoded proteins are identical in both species.
As a social animal, chimpanzees live in communities ranging anywhere from a dozen to more than 150 individuals, often with fairly complex social structures. They can learn to recognize numbers, display facial expressions, and use tools.
Chimpanzees are known to be self-aware (bodily awareness or self-recognition). A mirror study (in which animals are given access to a mirror to observe their reaction) conducted in the early 2000s revealed that many subject chimps showed mirror-self recognition traits.
In a multi-decade study conducted at the Primate Research Institute in Kyoto University, researchers found that chimpanzees are adept in learning and recognizing numbers (1 to 9).
A group of African bush elephants with calves in the middle at Amboseli National Park | Image Courtesy: Amoghavarsha JS
Weighing over 5 kilograms, the brain of an adult African elephant is more massive than any other land animal and is only outsized by that of a whale. Moreover, it contains nearly 257 billion neurons, about three times that of an average human brain.
Behaviors such as cooperation, compassion, selflessness, grief, and mimicry are widely observed in elephants. Along with great apes (including humans), magpies and dolphins, the elephant is one of the few animal species that exhibit self-awareness.
Elephants are known for their excellent memory. Studies have shown that it could be due to elephants having advanced cognitive mapping skills allowing them to remember vast spaces or locations for a long time. They don’t forget people either.
Elephants are also sharp-witted when it comes to problem-solving. An experiment conducted in 2010 revealed that elephants could learn to coordinate and work cooperatively more efficiently than most other animal species. In the experiment, a pair of elephants are required to simultaneously pull both ends of a rope to successfully retrieve the food.
A carrion crow in England | Image Courtesy: Jans Cannon/flickr
Crows are perhaps the most intelligent birds on earth. They are known to possess excellent memorizing abilities, use tools, steel and hide food, and the ability to learn from each other. A few species of crows and ravens perform better in cognitive tests than others.
The New Caledonian crow, found in New Caledonia east of Australia in the Pacific Ocean, has been observed to construct special tools to capture prey. These tools have a high level of standardization.
Other crow species, such as hooded crows in northern Africa, have mastered bait-fishing using bread crumbs. Furthermore, a study published in the Journal of Experimental Analysis of Behavior suggested that hooded crows may possess significant numerical abilities (based on matching and oddity tasks). In Queensland, Australia, Crows have apparently developed a strategy to feed on toxic cane toads that are lethal to many animal species when ingested.
Crows and their close relatives, including ravens and magpies, are known for their ability to recognize humans by their facial features. To test this, researchers conducted a campus-wide experiment in which volunteers wore ‘dangerous’ masks and walked on specified routes inside the campus. A month earlier or so, the same masks were used by a group of researchers to catch and trap several crows inside the university grounds but were later released.
It turned out that whenever individuals wearing the ‘dangerous’ mask take a stroll inside campus grounds, they get shouted at or scolded by crows.
Dolphins are perhaps the smartest aquatic animal in the world. They have a relatively high body-to-brain ratio of 1/50 (higher than that of chimps), able to display a wide range of emotions, perform mimicry, cooperate and even formulate schemes.
Mirror tests have shown that dolphins possess self-awareness. However, critics argue that mirror tests are not much effective on cetaceans (aquatic mammals) as their usual social conduct could be misinterpreted as a self-recognition behavior.
A paper published in 2004 reported that dolphins might share critical cognitive abilities with great apes, such as the ability to learn and master a symbolic language, self-awareness, and the capacity to cooperate. In an unrelated experiment conducted by the Institute for Mammal Studies in Mississippi, Kelly the dolphin displayed a sense of delayed gratification and even developed strategies to obtain regular fish treats from the trainers.
Spindle neurons, which are believed to be involved in conducting social behavior, judgment, and emotions in mammals, are found in the areas of the dolphin brain that are similar to where they are located in the human brain.
Honey bees on brood comb | Image Courtesy: Wikimedia Commons
Some of the best-known bee species, including bumblebees and honey bees, are highly social animals that display collective intelligence on par with humans. These bees are known for their collective decision-making abilities, whether it is for finding a new nest or a food source. When a decision is made with cognition, cooperation, and coordination of many individuals, it is called group or collective intelligence.
The working honey bees have an intricate way to communicate with each other, the “waggle dance.” Austrian ecologist Karl von Frisch was among the first to study this characteristic of bees. When a bee finds a food source, it relays the information of its location to other bees in the hive through dance.
To do this, the bee moves towards a certain direction in a straight stretch while waggling her posterior, then traces her way back in a semicircular pattern to the starting position whereupon she resumes the dance. The direction towards which the dancing bee moves in a straight line informs other bees about the direction of the food source. While the distance to the food source is relayed by the time taken to transverse the straight line. One second of waggle dance indicates approx. one-kilometer distance.
Studies have shown how a colony of honey bees can collectively choose the most profitable or more abundant nectar source and rapidly change its foraging efforts.
A common octopus | Wikimedia Commons
Based on their spatial learning capability, navigational skills, observational learning, and quirky predatory techniques, cephalopods can be considered as one of the smartest invertebrate animals. Cephalopod, which includes cuttlefish, octopuses, and squids, is a class (taxonomic category) of mollusks.
They can use tools
Octopuses are pretty flexible in tool use, an important factor for gauging intelligence. In more than one instance, the veined octopus has been observed to manipulate coconut shells and use them as a mobile shelter. While other sea creatures, such as hermit crabs, exhibit similar behavior, researchers believe that octopus’ fortress-making abilities are far more complex than that of others’. They are known to pick up and carry tools for later use.
Males and smaller female individuals of the common blanket octopus have been observed carrying tentacles of the venomous Portuguese man o’ war to protect themselves from predators and capture prey.
Otto, an aquarium octopus in Germany, was notorious for throwing rocks at his tank glass. He was once even found juggling a bunch of hermit crabs.
Octopus are sneaky escape artists
Octopuses are sneaky predators. While a large portion of their diet is made up of crabs, the powerful claws of sizeable crabs and overall quickness make it difficult for octopuses to catch them directly. Instead, they ambush lobster traps to catch their prey. They also sneak inside containers holding dead lobsters on fishing boats.
Octopuses are quite notorious escape artists as they often show tendencies to escape their enclosures. In 2016, Inky, a common New Zealand octopus, was able to escape from the National aquarium using a 50-meter drainpipe after breaking out of its tank.
A raccoon approaches a group of human | Image Courtesy: Wikimedia Commons/Paxson Woelber
The raccoon is a clever and intelligent animal known for its adaptability to a wide range of environments. Compared to dogs and cats, only a small number of studies have been carried out to determine the cognitive abilities of raccoons.
They are master lockpickers
In 1908, an experiment conducted by behavioral ecologist H.B. Davis revealed lockpicking abilities in raccoons. The subjects were able to open complex locks in much less than a dozen attempts. That’s not all. They were able to repeat their actions even when locks were turned upside down. Davis concluded that not only can raccoons learn at a higher rate but also understood conceptual principles of the locks.
Since the 1960s, a handful of researches have been carried out focusing on raccoon memory. One such study was published in 1992. Here, raccoons were able to easily distinguish symbols that were introduced to them three years ago during the initial learning phase.
In his book, ‘The Number Sense,’ cognitive neuroscientist and author Stanislas Dehaene reported that raccoons could instantly differentiate fruit boxes containing two or four grapes from those carrying three grapes.
They have been found to have the same amount of neurons in the cerebral cortex as dogs, though the size of the raccoon brain is similar to that of cats.
Due to their agile paws and intelligence, raccoons can perform many human-like actions, such as unscrewing jars and bottle corks. Some experienced members can even open doorknobs and latches.
Rooster | Image Courtesy: Wikipedia
Contrary to popular beliefs, chickens are intelligent and emotionally sensitive birds. Chickens or common fowls are the most abundant bird species in the world, with an estimated population of 25.9 billion as of 2019. Yet, there are many misconceptions about them.
Chickens are usually considered unintelligent species lacking advanced cognitive abilities. They are also viewed as emotionless creatures unable to feel happiness, frustration, and loneliness. However, that’s not the case at all.
Cognitive studies have shown that chickens possess at least some level of self-awareness, the ability to display emotional intelligence, have numerical understanding, and manipulative skills.
They are easy to teach
In 2015, a study conducted by researchers at the University of Adelaide, Australia, revealed that chickens are fast learners and are easier to teach new tricks/maneuvers. The research also concluded that chickens are emotional creatures.
Lori Marino of The Kimmela Center for Animal Advocacy examined selected peer-reviewed studies on chicken cognition, emotion, and individual personality and compared them with other vertebrates, including mammals. According to the author, this scientific review paper aims to educate the public about this domestic animal through scientific means. Lori Marino co-authored the first-ever paper on mirror self-recognition in bottlenose dolphins.
Possess basic arithmetic abilities
In a remarkable study led by psychologist Rosa Rugani at the University of Padua, Italy, various experiments were performed to analyze the arithmetic abilities in newborn chicks. These domestic chicks were first introduced to five identical objects.
After a few days, the objects were divided into sets of three and two and were concealed behind two black screens, all in the plain sight of young chicks. They instinctively probed the screen with more objects.
In a follow-up experiment where objects behind both the screens were interchanged, the results were quite the same as the chicks seem to keep track of the movement of the items and approached the screen with more objects. The study showed that chickens have a basic understanding of numbers and numerical tasks from a young age.