There seem to be fewer and fewer traits that we can consider to be uniquely human. Our closest relatives, chimpanzees and bonobos, seem to in many ways match us completely. They have tool use, self awareness, complex social systems, and even war. All of our good and bad traits are mirrored in their behavior, and it is sometimes hard to find an aspect of us that they have not demonstrated to some degree. Some people might bring up our use of fire and cooking, as that must surely be a human thing that no other animal can do, but you would be wrong, It turns out that there is a non-human primate out there who can not only build his own fires, but also cook up a nice meal for himself, among various other unique abilities, further tearing down the walls between us.
The male bonobo known as Kanzi was born in 1980 at Yerkes Field Station at Emory University in Atlanta, Georgia and had a bit of an unusual and turbulent youth. He was stolen from his mother at a very young age by another female of the group by the name of Matata, the chief leader of the group, and it was under her care that his unique talents would become known. They would be moved to the Ape Cognition and Conservation Initiative (ACCI), formerly the Great Ape Trust, in Des Moines, Iowa, where at the time, researchers were using Matata in an experiment to teach her language through keyboard lexigrams, which are basically symbols corresponding to objects or ideas. She had been undergoing constant training in communication through these lexigrams but had been struggling to pick up the 10 words researchers were trying to teach her. During these sessions, little Kanzi was just off on his own, seemingly completely disinterested in what the researchers and his adoptive mother were doing, off in his own little world, but then he would surprise everyone.
One day, during a break for Matata, Kanzi approached the lexigram keyboard and quickly began competently using the 10 lexigrams that the researchers had been trying to teach Matata. The researchers were baffled, as not only was this the first time a bobobo had demonstrated this ability to use language, but he hadn’t even been formally taught it, rather picking it up naturalistically through observation alone. Kanzi quickly picked up more lexigrams until he could use over 200 of them, able to hear spoken words and point to the correct ones almost without fail. Indeed, his ability to understand spoken words was highly advanced, equal to or beyond that of a 2-year-old human child. One of the main researchers who works with Kanzi, Dr. Sue Savage-Rumbaugh, Kanzi, has said he has shown a remarkable ability to "understand individual spoken words and how they are used in novel sentences," following complex commands that are spoken to him. She offers as one example that if he has a carrot next to him but is told to go get the one in the microwave, he will get up, go to the microwave, retrieve the carrot and bring it back. In one experiment giving him 600 spoken instructions asking him to deal with familiar objects in various novel ways, Kanzi was correct 74% of the time, whereas a 2-year-old girl used in the study was only 65% accurate. Presently Kanzi understands over 3,000 spoken words and can “say” close to 500 words by pointing to lexigrams.
Beyond his amazing language abilities with spoken words, Kanzi also taught himself American sign language by watching videos of the sign language-using gorilla Koko and he is also an uncommonly accomplished tool user. In one experiment he was tasked with trying to get food out of a clear box wrapped with rope. Researchers showed him how to flake a stone in order to produce a sharp, cutting edge, similar to what human ancestors did when making early stone age tools. It was theorized that he would be able to make a sharp edge and cut the rope to get the food, and Kanzi proved to be a fast learner. Not only did Kanzi figure it all out, but he even developed his own way of flaking the stones that was different from what he had been taught, impressing researchers yet again. However, he was still not finished baffling researchers, because he was soon about to show them something no ape had ever done before.
One very unique skill that Kanzi picked up was the actual ability to make fires. According to Savage-Rumbaugh, Kanzi would sit around watching the movie Quest for Fire constantly, and one day asked for some matches using sign language. Before long, he figured out how to use them and could actually start a fire, even figuring out what things he needed to prepare one. This had never been seen in a non-human primate before, but on top of this, one day he demonstrated the ability to actually cook. Savage-Rumbaugh has said of his fascination with fire and first time cooking something:
Kanzi makes fire because he wants to. He used to watch the film 'Quest for Fire' when he was very young, which was about early man struggling to control fire. He watched it spellbound over and over hundreds of times. In an outing in the woods in Georgia, Kanzi touched the symbols for "marshmallows" and "fire." Given matches and marshmallows, Kanzi snapped twigs for a fire, lit them with the matches and toasted the marshmallows on a stick.
Kanzi then moved on to using a pan to cook food over fires he built himself using matches, including even vegetables or other foods in the pan, flipping them in a way that one researcher described as “eerie” and “remarkably human.” This is not the first time primates have been shown to prefer cooked food, but it is the first time that a great ape has shown the ability to understand how to do it themselves and make a fire to do it. Making it even more impressive is that Kanzi also taught his son Teco how to do it, passing along his knowledge, and it is probable he would to teach it to other bonobos as well.
Interestingly chimpanzees have also been shown to prefer cooked foods and even use a “cooking tool” to do it. In one experiment in the Democratic Republic of Congo, a group of chimpanzees was given a “cooking box” which was actually just a bowl with a false bottom that held cooked food in order to give the illusion that it was cooking it. The chimps would put raw food in and cooked food would come out, to them appearing as if the bowl had cooked their food. When they realized this, they began using it regularly, even holding on to raw food until they could get to the machine, overcoming their impulse to eat food immediately, and before long they had taught the whole group how to use it. One of the researchers would say of seeing it dawn on these apes that they could cook food, “At first, the chimps pretty much ate the food. But then you almost could see them have this insight like, Oh, my goodness, I can put it in this device and it comes back cooked.” This shows that early humans likely also had an innate desire to eat cooked food and similarly learned how to go about getting it and passed this knowledge on. Richard Wrangham, a professor of biological anthropology and author of the book Catching Fire: How Cooking Made Us Human, has said of how our early use of fire and cooking came about in our early ancestors 400,000 and 2 million years ago and how it relates to the behavior seen in the chimps:
All they needed, I think, would be to see a piece of food drop in the fire, pick it out and realize that it tasted good, and then the cultural transmission of that behavior would spread very quickly. What we're seeing here is that the chimps are surprisingly similar to humans, even though the whole process of cooking seems like something that is a huge divide between humans and other animals.
This desire to cook and our ability to control fire would be a giant evolutionary step for us, leading to larger brain size and changes in social structures that would affect the entire course of our history. It is all very intriguing, but Kanzi is still the only non-human primate who can start his own fires and cook up a meal. He remains a unique curiosity among his kind, and a window with which we can perhaps look back into our past, back to when the first human ancestor first put that food on the fire and changed the course of our entire species.