Chimpanzees Build With A Drawing

The scientists from I.P. Pavlov Institute of Physiology, Russian Academy of Sciences, have investigated the intellectual abilities of chimpanzees in comparison with the children from a nursery school in Koltushy near St. Petersburg. They asked both to build the pyramids of cubes of different size. The children with the retention of speech development aged from 2 to 7 and two chimpanzees, female (aged 7) and male (aged 11) ones, took part in the experiment. The children and the apes were shown a pyramid and they had to build the same one. The only difference was that the children were explained the task and the apes were not obviously told anything and they should guess how to do it without any assistance.

At first, the construction consisted of only two cubes: big and small ones. Then they increased the number of cubes up to nine. The cubes had different sizes and, in addition, there was one unnecessary cube in the pile that the pyramid instanced did not contain. The scientists analyzed the time that the children and animals being tested spent trying to choose each detail and how much time it took them to clone the whole pyramid.

In the early stage both the children and the apes spent more time trying to complete the operation with increasing the number of cubes. However, they gained useful experience with time and started working quicker. The chimpanzees built pyramids of two or three elements as quickly as the children aged 3 or 4. When the number of cubes became higher the apes began to make mistakes and they often could not solve the task themselves. This fact especially concerned the male chimpanzee: in most cases it needed help and sometimes it simply refused to solve the task. The female monkey was younger and, perhaps for this reason, managed without any assistance more often. Both the apes and the children made mistakes if the number of cubes were higher than 4 or 5. Interestingly enough, having success in completing the task greatly depended not on their age but on the degree of speech development. The children who could not describe properly what they had seen and tell about an event even at the age of 6 or 7 solved the task not much better than chimpanzees.

At the later stage the experiment has been complicated. The children and the apes were suggested to build a pyramid not after a real pattern but using a picture. The chimpanzees understood the task and built a structure of three elements with a drawing rather successfully. When doing this they compared their pyramid with the drawing, placed it next to the paper and sometimes even tried to take a cube from the picture.

The experiment has given additional characteristics of chimpanzee intellectual abilities and the development of human intellect. The chimpanzees have shown that they can choose after the sample and are ready for constructive activity. The children have demonstrated that human thought greatly depends on the degree of speech development.