Scientists have solved a particularly difficult puzzle for chimpanzees, leading to a remarkable discovery

Scientists have discovered something very special: a chimpanzee who cannot solve a complex puzzle on his own is able to copy the solution from his peers who can.

Chimpanzees have long made scientists think: How can there be such large behavioral differences between different groups? For example, chimpanzees generally use sticks to hunt termites. However, not all chimpanzees do it the same way. In some groups, the chimps placed the sticks directly into their mouths afterwards. In other groups, chimpanzees first collect insects on their hands before eating them. It has long been assumed that these types of behavioral differences between groups arise because chimpanzees learn socially, first observing others of their own kind and then imitating them.

But recently, researchers have begun to question the ability of chimpanzees to copy complex actions from each other. They find it more likely that individual chimpanzees have to constantly figure out how something works, and that they can get inspiration by observing others. A recent study now shows that these doubts are unfounded. Scientists have now proven conclusively that social learning is indeed of great importance to chimpanzees. Researcher Edwin van Leeuwen contributed to the research. “Humans have a much stronger tendency to learn socially, whereas chimpanzees are more self-focused,” he says. However, this does not mean that they cannot do it (social learning, ed.) at all. The research has been published in the journal The nature of human behavior.

puzzle box
For the research, scientists used a very difficult puzzle box. This puzzle box contains peanuts. The chimpanzee could see and smell the peanut, but he simply couldn't get it. In preparation, scientists hid a whole collection of wooden balls in the area. To solve the puzzle box, the animals first had to find a wooden ball and take it with them to the box. Once they reached the puzzle box, the chimps had to grab a bar and push the wooden ball through a hole in the box. Ultimately, the chimpanzee was given a handful of peanuts as a reward. Finally, the scientists repeated the same experiment with a different group as a control group.

In both groups, no chimpanzee was able to solve the puzzle alone. “They did everything to get to the peanuts,” Van Leeuwen explains. They tried to open the lock on the lid of the box and used balls to tap the box and throw it. But none of the animals could find the solution.” It may seem strange, but that was exactly the intention. It was time for the next step: selecting and training a reasonably intelligent, high-ranking female from each group. “You can't pick an animal at random,” Van Leeuwen says. It must be an animal that dares to solve the puzzle in the group and is also allowed to eat. “For this one-on-one training, the puzzle box was temporarily removed from the group. The two females – one from each group – then learned from foragers outside their groups how to get peanuts. Once the females knew how to get food, the box was replaced. After two months, he saw The researchers already made a big difference: out of 66 chimpanzees, 14 were now able to solve the puzzle box.Further research revealed that these 14 chimps had seen in detail at least nine times when one of the chimps provided the solution.

Social education
The study's findings are important because they provide strong indications that chimpanzees can indeed acquire new and complex skills through social learning. Social learning is important because this model is viewed as one of the conditions for cumulative cultural evolution (CCE). CCE describes the process by which knowledge can be transferred from one generation to the next, causing so much information to accumulate over time that new technology can be created. Therefore, CCE is one possible explanation for the complexity and diversity of human cultures. In short, this may mean that chimpanzee culture is much more similar to our own than previously thought.

Despite the convincing results, Van Leeuwen believes it is still too early to draw broader conclusions. He concludes: “I believe that this study represents a valuable addition to current science about the evolution of culture, but it is of course only one study. I suspect that the main cause of differences in cultural expressions between humans and chimpanzees may have to be investigated in a different field.