MONKEY INTELLIGENCE: SELFIES, COUNTING AND SELF-RECOGNITION

MONKEYS CAN LEARN TO PASS THE MIRROR SELF-RECOGNITION TEST


Unlike humans and great apes, rhesus monkeys don't realize when they look in a mirror that it is their own face looking back at them. But, according to a study published on January 8, 2015 in the journal Current Biology that doesn't mean they can't learn to recognize themselves in a mirror and once they do they may use mirrors spontaneously to explore parts of their bodies they normally don't see. "Our findings suggest that the monkey brain has the basic 'hardware' [for mirror self-recognition], but they need appropriate training to acquire the 'software' to achieve self-recognition," says Neng Gong of the Chinese Academy of Sciences. [Source: Phys.org, January 8, 2015]

Phys.org reported: For many years, cognitive researchers have relied on the mirror self-recognition test as a means for determining if an animal is capable of self-awareness. A dye mark is made on the face of an individual being tested and then that individual is allowed to look at itself in the mirror — if it see the mark and touches it, then it passes the test. But more recently, some in the field have begun to question the validity of the test, suggesting that an inability to pass the test might be more of an indication that an animal simply does not understand how a mirror works. In this new effort, the researchers sought to see if that might be the case by training a group of male rhesus monkeys on how a mirror works before giving it the test.

In earlier studies, scientists had offered monkeys mirrors of different sizes and shapes for years, even beginning at a young age, Gong explains. While the monkeys could learn to use the mirrors as tools for observing other objects, they never showed any signs of self-recognition. When researchers marked the monkeys' faces and presented them with mirrors, they didn't touch or examine the spot or show any other self-directed behaviors in front of those mirrors in the way that even a very young person would do.

In the 2015 study, Gong and his colleagues sat the monkeys in front of a mirror and shined a mildly irritating laser light on the monkeys' faces. After 2 to 5 weeks of the training, those monkeys had learned to touch face areas marked by a spot they couldn't feel in front of a mirror. They also noticed virtual face marks in mirroring video images on a screen. They had learned to pass the standard mark test for mirror self-recognition. Most of the trained monkeys — five out of seven — showed typical mirror-induced self-directed behaviors, such as touching the mark on the face or ear and then looking and/or smelling at their fingers as if they were thinking something like, "Hey, what's that there on my face?" They also used the mirrors in other ways that were unprompted by the researchers, to inspect other body parts.

In February 2017, a team of researchers at the Shanghai Institutes for Biological Sciences said that rhesus monkeys can pass the mirror self-awareness test if they are first taught how mirrors work. In their paper published in Proceedings of the National Academy of Sciences, the team describes how they taught the monkeys to understand how mirrors work and how the monkeys behaved once they had it down. [Source: Bob Yirka, Phys.org, February 14, 2017]

The training involved placing a monkey in front of a mirror and rewarding him each time he correctly placed his hand on a spot in its cage lit up by a laser pointer on the wall behind the animal. Over time, as the monkeys got the idea, the pointer was eventually directed to its face, at which point, a given monkey would touch its face where the mark was — a close approximation of the self-recognition test.

The team then placed a dye mark on each of the monkeys' faces without them knowing it and then allowed them to look at a mirror — at that point, all of the monkeys individually noticed the mark and directed their hand to it, wiping at it and sniffing it. All of the test monkeys eventually passed the test, even while control monkeys continued to misidentify their own faces in the mirror as belonging to another monkey. This, the team suggests, indicates that the monkeys are clearly capable of passing the self-recognition test, and thus have self-awareness. Their claims were further bolstered by continued monitoring of the trained monkeys as they sat in front of a mirror with no direction. They used the mirror to check out normally unseen body parts, such as their genitals and to preen themselves. This, the team suggests, clearly shows that having learned how a mirror works, the monkeys truly demonstrated that they were aware of themselves.

Monkeys in Brazil Make Hominin-Like Stone Tools


tool use by a capuchin monkey

At a national park in Brazil scientists watched Capuchin monkeys smash stones against each other, splitting off sharp-edged flakes that resembled cutting tools early hominins. The monkeys smacked the rocks together, for reasons that aren’t clear, but may involve licking the broken surfaces for silicon, an essential trace nutrient. Sometimes the rocks broke in ways that created flakes or left broken rocks with sharp edges suitable for cutting or scraping. The monkeys didn't use them like that but the researchers wrote that “the production of archaeologically identifiable flakes and cores, as currently defined, is no longer unique to the human lineage.” [Source: Samir S. Patel, Archaeology magazine, January-February 2017]

Associated Press reported: “The monkeys ignored the flakes, focusing on the damaged stones instead. So they clearly weren’t deliberately making them as tools. But if ancient monkeys did the same thing, their unintentional handiwork could be mistaken for deliberate tool-making by human ancestors, researchers said. “The scientists are not suggesting that any stone tools attributed so far to human forerunners were instead made by monkeys, said Tomos Proffitt of Oxford University in England. Those tools, which date back as far as 3.3 million years ago, are more complex than what the Brazilian monkeys make, he said. But as scientists look for earlier and earlier tools, their findings may begin to resemble the monkey flakes more strongly, said Proffitt, lead author of a study released by the journal Nature. [Source: Associated Press, October 19, 2016 -]

Rhesus Monkeys Can Count?

In the late 1990s, Science News reported: “Rhesus monkeys can distinguish between varying numbers of items, from one to nine, and correctly order them from the smallest to the largest a study suggests. These results offer the strongest evidence to date that non-human primates wield numerical knowledge, say psychologist Herbert S. Terrace and psychology graduate student Elizabeth M. Brannon, both of Columbia University. [Source: Science News, July 11, 1998]

Since the monkeys make no obvious attempts to count on their fingers and maintain a humble silence in the face of researchers' questions, it remains difficult to pin down the mental tactics they use in determining that, for example, five diamonds represent a lesser quantity than six rectangles. The animals apparently have learned some type of numerical rule for ordering amounts from one to nine, Brannon theorizes. "We don't have direct evidence yet, but it seems likely that these monkeys, and other nonhuman primates, can count," she says.

Terrace and Brannon presented two male rhesus monkeys with a series of 35 displays, each consisting of four images, on a touch-sensitive computer screen. Each image portrayed a different object in numbers ranging from one to four. Images were arranged randomly, from left to right. They might show, for example, two bananas, one triangle, four apples, and three hearts. The size, surface area, shape, and color of objects were also changed randomly from one display to the next. The monkeys rapidly learned to touch pictures in ascending numerical order when they received food pellets for correct answers. After errors, the screen turned blank, and a few seconds later, a new set of pictures appeared.

A subsequent series of displays presented arrays of four different objects shown in quantities ranging from five to nine. The monkeys ordered these novel amounts as accurately as they had learned to order the smaller numbers of items, the investigators report in the Oct. 23 SCIENCE. In a final trial, the rhesus duo usually distinguished smaller from larger amounts, ranging from one to nine, in pairs of images.

Numerical Abilities of Rhesus Monkeys

On the same research mentioned above Bob Nelson wrote in the Columbia News, “Two Columbia University psychologists have taught monkeys to discriminate computer-generated images containing as many as nine objects and to respond to them in ascending order, with a success rate well above what would be predicted by chance. The work is the strongest evidence so far of numerical ability in non-human primates, said the researchers, Herbert S. Terrace, professor of psychology at Columbia and professor of psychiatry at the New York State Psychiatric Institute, and Elizabeth Brannon, a Columbia graduate student in psychology. Their work appears in the January issue of the Journal of Experimental Psychology: Animal Behavior Processes. [Source: Bob Nelson, Columbia News, September 18, 2002]

The research challenges the prevailing view, which dates to Descartes, that non-human primates cannot think because they cannot use language. It also challenges the views of B.F. Skinner, the noted behaviorist and Terrace's mentor at Harvard, who held that all examples of animal intelligence were simply conditioned behavior that didn't require cognitive explanations. Terrace and Brannon believe that cognitive processes -- thought -- are needed to explain the kind of complex behavior they are studying. They hope to show that human intelligence, like other human attributes, can be traced to animal origins.

"We have ample evidence that animals can think without language," said Terrace, who heads Columbia's Primate Cognition Laboratory. "In our current and previous research, we have shown that animals solved complex problems without help from external cues." Added Brannon, "Though monkeys do not recognize the word 'two' or the symbol '2,' they share with humans the capacity to master simple arithmetic, on at least the level of a two-year-old child. We don't have direct evidence yet, but it seems likely that these monkeys, and other non-human primates, can calculate."

In a recent series of experiments, Brannon and Terrace trained two male rhesus monkeys, Rosencrantz and Macduff, by presenting them with 35 sets of images on a touch-sensitive video screen. Each picture contained a different number of different objects from one through four, for example, one triangle, two bananas, three hearts and four apples. The stimuli appeared in random positions on the screen, to prevent the monkeys from learning the required sequence as a series of fixed motor movements. Other features of the pictures unrelated to number, such as size, surface area, shape and color, were also varied randomly.

When the monkeys touched the pictures in ascending order, i.e., one square, two trees, three ovals and four flowers, they received a banana-flavored food pellet. If they made an error, the screen turned black for several seconds and a new trial began with different pictures. This "video game" paradigm, which the monkeys now clearly enjoy, trained them to perform cognitive serial tasks without verbal instructions -- without language, the researchers said.

"It's like using your password to get money from a cash machine, but it's actually much harder for the monkeys," Terrace said. "The pictures, and their position on the screen, change each time they try for another pellet of food. When you go to a cash machine, you don't have to deal with the numbers being in strange positions each time. We ask a lot, cognitively speaking, of our non-human primate subjects."

Over the course of learning 35 different training sets, the monkeys got better and better at responding in the ascending numerical order, one to four. The two psychologists then tested Rosencrantz and Macduff on 150 test trials, in which a new stimulus set, showing numbers of objects from five to nine, was presented on each trial. The monkeys performed just as well as they had on the original 35 training sets. "There was no way the monkeys could have done this, unless they had learned some numerical rule for ordering the contents of the pictures," Brannon said.

To test whether the monkeys understood the ordinal relations between non-consecutive numbers -- that, for example, five is greater than three -- Brannon and Terrace gave the monkeys a new set of problems in which they were shown up to nine objects. The task was to first touch the picture containing the smaller number of objects, then the one with the larger number of objects. For example, if a monkey was shown one picture with five large circles and another containing seven small circles, the correct order was five, then seven. Rosencrantz and Macduff responded correctly even when the number of objects in the pictures exceeded four.

"This finding is important because it shows that monkeys know things about number that we haven't taught them," Brannon said. Brannon and Terrace believe that arithmetic and language evolved separately, and that number skills preceded human speech. "Language is a complex social skill, whereas counting can be learned by the individual," Terrace said. "Counting is useful in foraging for food, assessing a group of predators or ordering the number of dominant males in one's group."

“After several months, researchers stopped treating the corn with aloe, but monkeys continued eating only the color that had never been made bitter. Dominant monkeys never sampled the disliked color; subordinate monkeys might, but only if dominants were hogging the liked color. Baby monkeys, which received no color training, instantly ate only what their mothers ate, even squatting on the other color, “totally ignoring that there was an edible color under their feet,” Dr. van de Waal said.

“Most strikingly, when male monkeys migrated from a different-colored region, they ate the local color. The one exception was a blue-is-best male who entered a pink area with no dominant male, took control and continued eating blue corn. But he “might be a stupid male that had too much testosterone and was just not looking at what the others are doing,” Dr. van de Waal said.

Monkey Selfies Found on Lost Phone in Malaysia

In September 2020, a Malaysian man aid he found monkey selfies and videos on his missing phone a day after retrieving it in the jungle behind his house. The BBC reported: “The content — including footage of a monkey that appears to be trying to eat the phone — has been widely shared on social media since Zackrydz Rodzi posted it on Twitter. The man — a student — said he thought his phone had been stolen while he was sleeping. But it remained unclear exactly how the mobile went missing. It was also not possible to verify the circumstances in which the photos and videos ended up on his phone. [Source: BBC, September 15, 2020]

“Mr Zackrydz, 20, told the BBC he realised his smartphone was gone when he woke up at around 11am on Saturday morning. “There was no sign of robbery. The only thing on my mind was is it some kind of sorcery," said the final year computer science student from Batu Pahat in the southern state of Johor. A few hours later, in a video shared with the BBC that was time-coded 2.01pm that same day, a monkey appeared to be trying to eat the phone. The primate can be seen staring down the camera against a backdrop of bright green leaves and crowing birds. There were also a series of photos of the monkey, trees and other foliage on the phone.

“Mr Zackrydz said he failed to find any trace of his phone until Sunday afternoon when his father noticed a monkey outside their house. On calling his phone again he heard ringing from the jungle a few steps beyond the back garden, he said, then discovered the muddied phone on some leaves beneath a palm tree. His uncle joked that maybe there was a photo in the phone of the thief, he said, so after cleaning it he opened the picture gallery "and boom, it's full of monkey photos".

“Unlike some parts of the world where monkeys live in or near urban areas, there is no history of monkeys stealing things from houses in the local neighbourhood, said the student. He suspects the monkey may have entered the house through his brother's open bedroom window. “Something that you might see once in a century," he tweeted on Sunday in a post that was shared and liked several thousand times and picked up by local media outlets.

“It wasn't the first time monkey selfies have made headlines. In 2017, a British photographer settled a two-year legal fight against an animal rights group over a image taken by a macaque. In 2011, Naruto, a macaque monkey in the Indonesian jungle, picked up a camera owned by David Slater from Monmouthshire and snapped a series of "selfies". Mr Slater argued that he owned the copyright to the widely shared image, but animal rights charity Peta said the animal should benefit because it clicked the shutter. A US court ruled that copyright protection could not be applied to the monkey and dismissed Peta's case, but Mr Slater agreed to donate 25 percent of any future revenue from the image to charities protecting Naruto and other crested macaques in Indonesia.

Image Sources: Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated December 2024


This site contains copyrighted material the use of which has not always been authorized by the copyright owner. Such material is made available in an effort to advance understanding of country or topic discussed in the article. This constitutes 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. If you are the copyright owner and would like this content removed from factsanddetails.com, please contact me.