Over the past half-century, the field of animal cognition has grown tremendously. This ever-increasing interest in both the scientific and public spheres has allowed a spotlight to fall on animals who demonstrate impressive levels of intelligence. In this article, we cover 5 animals who became famous for their intellectual accomplishments.

1. Alex the African Grey Parrot

Alex is perhaps one of the most famous animals on this list, and likely the world’s most famous parrot. The iconic African grey was the research subject of scientist Irene Pepperburg1 for 30 years. He was purchased by Pepperburg at the age of one, and died unexpectedly in 2007.



In his time, Alex performed many feats as a part of Pepperburg’s studies. The parrot could correctly identify different colors, shapes, and materials. He could also recognize distinct categories, and identify objects that belonged to certain categories despite the individual objects being very different from each other. For example, Alex would correctly identify keys as keys, even when they greatly varied in size, shape, and color. He could even point out how certain keys differed from each other.

Alex’s other accomplishments include being able to name the number of objects laid out before him, recognizing numbers by their numeral symbols (Ex: “four” as 4), and correctly using personal pronouns (Ex: “I”, “you”).

Despite having an extensive vocabulary of over 100 words and being able to communicate vocally, Pepperburg never claimed that Alex possessed actual language. ”I avoid the language issue. I’m not making claims. His behavior gets more and more advanced, but I don’t believe years from now you could interview him. What little syntax he has is very simplistic. Language is what you and I are doing, an incredibly complex form of communication.”2

It’s important to note that Alex didn’t always answer questions correctly. Pepperburg often explained such instances as cases of Alex getting bored or annoyed. When Alex seemed to be in a bad mood, he would sometimes answer all questions incorrectly. Pepperburg has stated that such a thing would have been unlikely to happen by chance. If Alex were simply giving random answers, it’s statistically more likely that he would have luckily gotten at least one or more of the questions right. Pepperburg proposed that these all-wrong answers showed Alex did it deliberately: he had to know the right answers in order to avoid giving them each time.

There has been some criticism of Pepperburg’s work with Alex, suggesting that Alex’s responses were the result of rote learning or operant conditioning, not an actual understanding of the concepts. However, Pepperburg did place controls against cuing and expectation, such as using numerous human handlers, unfamiliar objects during testing, and objects that were not used exclusively for one type of task.

Pepperburg continues her research with other parrots at The Alex Foundation. One of them is Griffin, a parrot who has appeared on television displaying his own skills and intelligence.

2. Chaser the Border Collie

It’s not unusual when a dog learns to recognize a few words. Many dog owners chuckle about how their pets get excited when they hear the word “outside”, or make themselves scarce when they hear the word “vet”. But the vocabulary of most dogs hardly compares with that of Chaser the border collie, who knows over 1,000 words. She recognizes the names of her 900+ toys, and is even able to use deductive reasoning to figure out the names of unknown objects. You can watch her perform this impressive reasoning task in the video below.

In addition to the names of all of her toys, Chaser also knows the meaning of certain verbs, adverbs, and prepositions. She even comprehends phrases with multiple elements of grammar (Ex: “take ball to frisbee“). And like Alex the parrot, Chaser can identify objects that belong to specific categories. For instance, she knows that a “ball” can be any orb-shaped object.

Chaser’s owner is retired psychologist, Professor John Pilley of Wofford College. Pilley began teaching Chaser words from the very beginning. After 5 years of intensive training, Pilley had yet to find a limit to Chaser’s capacity for vocabulary. The training stopped at 1,022 words—not because Chaser couldn’t remember any more, but simply because there was no longer enough time to devote to the training. Pilley himself could not remember all of the words Chaser had been taught. He published his findings in 2010.3,4 It was then that Chaser quickly became the poster dog for canine cognition research.

3. Kanzi the Bonobo

Shortly after Kanzi was born in 1980, he was stolen from his biological mother by a dominant female. Matata, his new adoptive mother, was a research subject at Georgia State University’s Language Research Center. She didn’t care much about participating in her lessons, during which researchers attempted to teach her language through keyboard lexigrams (symbols representing words). Kanzi, however, did show a spark of interest, and talent as well.

He had been accompanying Matata to her lessons, and seemed to have learned just through observation. Kanzi began to correctly use some the lexigrams on his own. This made him the first non-human ape to learn elements of language without direct training. Moreover, Kanzi was the first bonobo to use any aspects of language at all.

Over time, Kanzi has learned over 500 lexigrams, and can combine those lexigrams to describe objects, form requests, and make decisions. In a 1993 study, he performed better than a human 2-year-old at responding to verbal requests.5 And though Kanzi’s anatomy prevents him from speaking as humans do, he does vocalize when he communicates with humans. Many of the sounds he makes seem to consistently correspond with the lexigrams that he selects.6 Another one of Kanzi’s recent claims to fame is learning how to set a fire and even roast marshmallows.

Kanzi currently lives at the Ape Cognition and Conservation Initiative (ACCI), where he continues to participate in language studies.

4. Natasha the Chimpanzee

Natasha is a rescued chimp living at the Ngamba Island Chimpanzee Sanctuary in Uganda. There, she occasionally takes part in research projects, through which she has developed a reputation for great intelligence. She quickly distinguished herself as the smartest chimp at the sanctuary because of not only her performance on tests, but also her mischievous antics.7,8

Her caretakers began to recognize Natasha’s smarts after incidents such as her escaping from her enclosure, or beginning to clap her hands at feeding time to attract more attention (and thus food) from the humans. Natasha has also made a hobby out of luring the sanctuary’s visitors toward her, then throwing water at them.

A 2012 study set out to answer the question: “are there geniuses among the apes?”.9 Natasha took part in this study, being one of the 106 chimpanzees given forms of IQ tests. Tasks involving tool-use, communication, and social learning were all incorporated.

Analysis of the results showed that, when it came to social cognition, Natasha ranked the highest out of all the chimps tested. This means that she showed a much better understanding of social situations than her peers. The scientists regarded her performance as exceptional.

5. Akeakamai the Dolphin

This female dolphin was a research subject at the Kewalo Basin Marine Mammal Laboratory. Here, she and her tank-mate, Pheonix, took part in the animal language studies conducted by marine biologist Louis Herman.

Unlike primate language studies carried out around that time (the 70s & 80s), the tests did not require the dolphins to use any language themselves. The research10 exclusively tested whether or not the dolphins could understand elements of language that were communicated to them by humans.

Akeakamai and Phoenix were taught how to recognize “words” conveyed through different mediums. Akeakamai was taught words that were represented by different gestures made by a human handler’s hands and/or arms. Phoenix was taught by another mode: hearing words represented by computer-generated electronic sounds. These sounds were played to Phoenix via an underwater speaker.

Both of the dolphins successfully learned individual words, and eventually strings of words (referred to as “sentences” in the study). Impressively, the dolphins could understand instructions given with different grammatical structures and different word orders. They comprehended the difference between instructions like “take the hoop to the ball” and “take the ball to the hoop“. By correctly carrying out the requested actions, the dolphins showed that they understood these elements of language.

Even more remarkably, the dolphins seemed to be able to creatively collaborate. Human handlers asked the dolphins to come up with their own trick together, using the commands “tandem” and “create”. The dolphins responded with a synchronized behavior of their own choosing, such as diving backward or splashing their tails.

There are two possible explanations of the dolphins’ ability to successfully perform a trick together on the fly: 1. One of the dolphins would take the lead by choosing the behavior and the other would imitate the leader’s actions. 2. They would confer with each other by communicating. So far, there hasn’t been any concrete evidence that either theory is true.

Unfortunately, Akeakamai died from cancer in 2003. Other dolphins continue to be taught with similar methods by other scientists and facilities, and they show the same ability for creative collaboration.11

Caveats

The five aforementioned animals became famous for their intelligence because they performed exceedingly well on various cognitive tests. But it’s not uncommon for some such tests to be somewhat anthropocentric in their design.

For example, the mirror test is used to test for self-awareness in animals, but the test relies heavily on vision and an animal’s motivation to investigate unusual markings on its body. Like with many other types of cognition tests, the required reactions may be typical of humans, but not for other species.

An animal’s senses and/or anatomy may not accommodate the desired reaction, or they may not have the same interests and incentives that would normally drive a response humans tend to have. Animals who fail to react as a human would are not necessarily unintelligent, and those that do manage to perform well on anthropocentric tests may be even smarter than we them credit for.

It’s also important to note that all of these animals were kept and tested in captive environments not representative of their natural habitats. Their behaviors and performances should be considered in the context of each animal’s upbringing, living situation, and testing conditions. It’s possible that the animals that live in highly-stimulating captive environments outperform peers in less-stimulating environments, or even their wild counterparts. Conversely, it could be that the pressures and stimuli present in the species’ natural habitat would normally elicit higher performance levels.

These caveats should be kept in mind when attempting to compare the intelligence of these individuals to others of their species. Nevertheless, these five animals have been the subjects of outstanding contributions to animal cognition research, and have had a major impact on the public’s growing recognition of animals as intelligent beings.

This article was written by Amanda Pachniewska, founder and editor of Animalcognition.org.

Sources

1 – List of Research Published by The Alex Foundation

2 – Dinita Smith

A Thinking Bird or Just Another Birdbrain?

The New York Times

3 – John W. Pilley, Alliston K. Reid

Border collie comprehends object names as verbal referents

Behavioral Processes

4 – Border collie comprehends over 1,000 object names

Elsevier

5 – Savage-Rumbaugh, S., & Lewin, R.

Kanzi: The Ape at the Brink of the Human Mind.

6 – P. Segerdahl, W. Fields, S. Savage-Rumbaugh

Kanzi’s Primal Language: The Cultural Initiation of Primates into Language

7 – Simon Tomlinson

Meet the primate prodigy: Natasha the chimp genius stuns scientists with her human-like levels of intelligence

Daily Mail

8 – Sarah C.P. Williams

Natasha, ‘Genius Chimp,’ Aces Intelligence Tests

Huffpost – Science

9 – Esther Hermann, Josep Call

Are there geniuses among the apes?

Philosophical Transactions of the Royal Society B – Biological Sciences

10 – Louis M. Herman

What Laboratory Research has Told Us about Dolphin Cognition

University of Hawaii and The Dolphin Institute, U.S.A.

11 – Joshua Foer

It’s Time for a Conversation: Breaking the communication barrier between dolphins and humans

National Geographic