Humans have always assumed that we were the only species with the cognitive capacity for cooking, but it turns out chimpanzees can grasp the concept too. Researchers Felix Warneken and Alexandra Rosati have discovered that the understanding of the transformation from raw food into cooked food is shared by humankind’s closest animal kin.
— Nsikan Akpan (@MoNscience) June 2, 2015
First of all, chimpanzees prefer food that has been cooked over raw food, the researchers claim in an article published in Proceedings of the Royal Society B. When given a choice, chimpanzees choose cooked food over uncooked food. Cooking involves a number of cognitive capacities that have always been believed to be reserved to human beings. After all, we don’t see animals, not even chimpanzees, starting campfires and cooking their own food. What if the prerequisite of fire-starting were removed from the equation though? Warneken and Rosati wondered just that.
“People focus on the control of fire because that seems so salient, but even if you had a fire stick, several other insights are required before you can use it for cooking,” Rosati explained. “Obviously, chimps can’t control fire, but we were trying to hypothesize about some of the other aspects of cooking, like the causal understanding that if you put this raw food on the fire it creates cooked food, or at the extreme end of our study, the ability to plan. What’s particularly interesting about cooking is it’s something we all do, but it involves a number of capacities that, even without the context of cooking, are thought to be uniquely human. That’s why we wanted to study this in chimpanzees.”
So, the researchers headed to the Republic of Congo and conducted a series of tests at the Jane Goodall Institute‘s Tchimpounga Chimpanzee Sanctuary that would answer their questions.
Warneken and Rosati studied wild-born chimpanzees in order to see if these primates were able to make the cognitive leaps that are necessary for cooking. Science Daily explained the research that took fire out of the scene.
“To explore those questions, researchers presented chimps with two devices — a ‘cooking device’ that turned raw into cooked slices and a control device that left it unchanged. During the critical test, chimpanzees saw raw sweet potato go into both, but had choose one device before seeing its (possibly transformed) contents. Warneken and Rosati explain that nearly every chimp reliably picked the cooking device, suggesting they quickly understood the transformation that was at work.”
That was pretty amazing, but an additional experiment was even more telling of the chimpanzee’s ability to comprehend the process and rewards of cooking food.
“We had done one season of testing and we thought what we had was interesting, but then we wondered if they might be able to hold on to the reward and actively choose to put it in the cooking device,” Warneken explained, according to Science Daily. “That’s really tough because usually when chimps have food, they eat it.”
“I thought there was no way they were going to do this,” Rosati said of the cooking challenge. “There is quite a lot of research that says animals have problems with self-control when it comes to possessing food, but we were leaving the sanctuary in a few days so we decided to try it.”
Shockingly, some of the chimps who had been exposed to the “cooking device” chose to delay immediately satisfying their urge to eat food and instead, when given the raw food, chose to let go of the food they had and place it into the “cooking device.” Once the first chimp did this, others decided to try it too. Before the researchers left the Jane Goodall Institute’s Tchimpounga Chimpanzee Sanctuary, about half of the chimpanzees chose to delay their gratification in exchange for the cooked food they preferred.
That still wasn’t all though. In the earlier tests, chimpanzees had been choosing to cook their raw sweet potatoes, but the chimps ended up transferring this concept of cooking raw foods on to the carrots they were given.
“The key thing here is that they had never seen carrot being put in these devices,” Rosati said, “but they were still able to generalize that process.”
It’s not like the chimps just find it rewarding to put things into a cooking device though. The chimps only put food into it. Even when they were given a small piece of wood at the same time as a piece of raw potato, the chimps didn’t put the wood in it. The chimpanzees were even able to demonstrate the ability to save the raw food so that it could be cooked later.
If chimpanzees can demonstrate cooking comprehension and the satisfaction of cooked foods, could other animals?
[Photos via Rosati’s webpage and Warneken’s webpage]