2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Of all the arguments proving that humans are fundamentally different from animals, the most compelling one concerns a person's ability to understand someone else's consciousness. Only people can not only perceive their experiences, but also realize that the thoughts and views of other people are different from their own. However, the results of the latest study published in Science suggest that monkeys are endowed with the same ability.
In the late 1960s, Emil Menzel conducted the following experiment: he showed one monkey where there is food in a large garden, or, conversely, something dangerous (for example, a toy snake). Then he returned the monkey to the flock and released them all together into the garden. The monkey, who knew where the food was, was followed by the congeners, while the monkey with information about the danger was avoided. This is how Menzel proved that monkeys can pass on the knowledge they have received to others. Later, repeating and supplementing these experiments, psychologists David Primack and Guy Woodruff in 1978 formulated the theory of mind, or the theory of understanding consciousness - the ability to realize that someone else's consciousness is different from yours, and to act accordingly.
The theory of mind soon became the foundation of developmental psychology. Many studies followed, including on animals - on birds and monkeys. By 2016 alone, Primack and Woodroof's original article had been cited 5,700 times! But all the debate about the theory of the mind in animals has converged on one thing: only humans can understand that other people's beliefs can be false.
The classic problem of understanding false beliefs is as follows: the child is shown two dolls, one doll hides its toy and leaves. After that, while the first doll is gone, the second doll hides the toy and also leaves. The first doll returns, and the child is asked where the doll will look for the toy. Children under four years old cannot solve this problem correctly.
In 2007, an innovative approach showed that in fact, children under the age of four are able to recognize that other people may have false beliefs: as early as two years old, children correctly predicted where the doll will look for the toy. In this experiment, instead of asking questions (and thus introducing another variable - the ability of children to understand and answer a question), the scientists tracked the children's eye movements.
It was this approach that inspired Michael Tomasello and his colleagues to repeat the study in monkeys. They used 19 chimpanzees, 14 pygmy chimpanzees and 7 orangutans. All the animals watched the video, where at first one actor hid the object, say, under the left box, and the second actor, in the absence of the first, first hid the object, and then simply carried it off the stage. In the experiment, the monkeys correctly predicted that the first actor, upon returning, would look for the hidden object under the left box, even though they knew that the object was no longer there.
These data suggest that monkeys may still be aware of the presence of other people's false beliefs. This means that we are again returning to the beginning of the search for that very unique quality of a person. And once again we reaffirm the old mantra: lack of evidence is not proof of absence. This is a good lesson for those who are in a hurry to proclaim the exclusivity of man in everything. It is easier to consider whether animals have a "mind", not from the "all-or-nothing" approach, but by dividing this "mind" into components, some of which may be universal for animals and for humans.
The new experimental method, which does not include binding to language, allows the theory of consciousness to be viewed in a broad biological context. Most likely, the ability to understand each other arose in complex communities (in monkeys and humans) in order to better predict the behavior of congeners. It is possible that this ability is distorted in patients with autism and schizophrenia.