Since time immemorial, anthropocentrism has led us to think that human beings are the only species capable of recognizing itself and having self-awareness. However, research has shown that this is not the case and that many other animals, such as dolphins, orangutans or elephants, could have this same ability.
To study this phenomenon, the mirror test has been used, a test that, until now, has been used to measure self-recognition or self-awareness in animals. And we say until now because in recent years, with the discovery that even ants or fish pass the test, part of the scientific community has questioned the validity of the test to measure this cognitive ability.
In this article we explain What is the self-awareness mirror test? and what are its limitations. In addition, we review the latest research on this interesting phenomenon.
The self-awareness mirror test: what is it and what is it for?
The mirror test, developed in 1970 by Gordon G. Gallup Jr, is a test that measures the level of self-awareness and visual self-recognition. What the test determines is If an animal can recognize its own reflection in a mirror as if it were an image of itself
This test is quite simple: just put a mirror at the animal’s disposal and observe its behavior. When the animal gets used to the mirror, the researchers mark with an odorless dye a part of its body that cannot be seen without the help of the mirror. Thus, if the animal reacts in a manner consistent with being aware that the dye is in its own body, positive evidence of self-awareness is obtained
Behaviors that indicate that the animal is able to recognize itself in its mirror image include turning and adjusting its body to better see the mark in the mirror, or touching the mark with its own body or a finger while looking at the mirror. The animals that until recently had passed the mirror test have been: chimpanzees, bonobos, orangutans, dolphins, elephants, common pigeons and, of course, humans.
However, recent research has found that Even some species of ants and fish have reacted positively to the self-awareness mirror test which has generated great controversy in the scientific community, dividing opinion between those who believe that the test is neither valid nor conclusive and those who believe that the implications it may have for the study of human self-awareness must be reconsidered.
Research with wrasse fish
One of the studies that has revolutionized the field of self-awareness research in animals has been the research by Kohda and others (2019) in which The behavior of a fish from the wrasse family was observed under the conditions of the mirror test
The results of the study concluded that the fish reacted to its reflection when looking in the mirror and met all the criteria of the mirror test. However, when the fish was provided with a colored label in a modified marking test, the animal attempted to remove the label by scratching its body in the presence of the mirror, but showed no response toward transparent or colored labels in the absence of the mirror.
For the authors of the study, although the wrasse shows behavioral responses that meet the test criteria established for other animals, The result does not imply that this species is self-aware All in all, the results of this research raise several questions that remain to be resolved: is this test really valid for detecting self-awareness in animals? And if so, if this species of fish is self-aware, should we rethink the concept?
Does the mirror test really measure self-awareness?
The validity of a test like the mirror test had not been seriously discussed until the publication of new research with animal species that, a priori, we would never have thought were capable of showing signs of self-awareness. The positive evidence in fish and ants has forced a large part of the scientific community to raise doubts about whether the mirror test is a good measure of self-awareness.
Alex Jordan, an evolutionary biologist and one of the authors of the controversial study on wrasse fish, is reluctant to point out that fish are as intelligent as chimpanzees or 20-month-old human babies can be, and questions the validity of the test. mirror to measure the concept of self-awareness.
According to Jordan, one of the problems with the test is that it uses vision to measure self-awareness. However, Not all animals (or all humans) rely on sight as the predominant sense For example, it is possible that bats, which rely on their sonar to navigate, are self-aware and we simply are not able, as humans, to formulate a test that detects this due to our visual bias.
Likewise, although elephants can pass the mirror test, they rely more on smell than sight, and the sophistication of their consciousness may have led to misleading interpretations. In this sense, this test may simply not be suitable for some animals, because we do not have the same sensory view of the world.
The “olfactory” mirror test
To overcome the visual bias of the self-awareness mirror test, Horowitz et al (2017) designed a sniff test for dogs that involved altering the smell of their urine It should be noted that these animals have not passed the traditional test, since they are not able to recognize themselves in the mirror.
In the experiment, the researchers presented the dogs with various containers. Each of them with an olfactory stimulus: in one, the dog’s own urine; and in the other, urine whose smell had been altered. By observing the time each dog remained in the containers, It was found that they were able to distinguish between the olfactory “image” of themselves and the modified one tracking its own scent longer when it had an additional scent accompanying it than when it did not.
The ecological validity of the olfactory test was examined by presenting the subjects with odors from other known or unknown dogs: the dogs spent more time investigating the odor of other canids than their own odor. Finally, in a second experiment, the dogs spent more time with the modified stimulus than with the modified odor alone, indicating that novelty alone did not explain their behavior.
In short, the results of this research suggest that Dog behavior involves certain recognition of one’s own scent, which translated into the traditional self-awareness mirror test implies the existence of visual self-recognition or “self-awareness” in these animals. Something that should not surprise all those people who live with these domestic creatures.
