There are those who cast a furtive glance and then move away indifferently, those who observe curiously, sketching some strange moves and those who assume an aggressive posture to defend themselves from the alleged threat. These are just some of the reactions we can observe in the images of Xavier Hubert Brierre, the French photographer who flew to Africa to see how wild animals behave when they are faced with their own image reflected in a mirror.

Where and how. Filming was conducted in the equatorial forest of Gabon, where tens of thousands of chimpanzees (most of the world population) live, gorillas and elephants, as well as numerous other species of primates, mammals and reptiles. For his experiment, the French photographer used a large mirror and a series of motion sensors, which triggered a hidden camera whenever an animal passed nearby.

Who is that? The range of reactions is varied and never banal. The elephant, for example, is reflected for a short time, only to leave almost bored. The leopard looks for a contact with its own reflected image, showing an attitude very similar to what we can find in domestic cats. Among the primates, the aggressive behavior of the gorilla stands out, which violently charges the mirror, while between the chimpanzees there are contrasting reactions, ranging from the nervous to the "vanesi". But there are also those who, like the baboon, go around the mirror and presumably go in search of the other monkey.

What science says. Xavier Hubert Brierre's work does not hide any scientific ambition. His goal was to collect a sample of curious behaviors to be shown by the general public, and it was no coincidence that the video immediately became viral, collecting millions of views on YouTube.

However, the video raises intriguing questions: do the creatures we see in action have any self-consciousness? The question appears complex, because in the past several experiments have shown that, in addition to man, other animals are also able to recognize their own reflected image.

Mirror test. In children the ability to recognize themselves matures at about 18 months. If you stick a colorful sticker on their foreheads, they notice it as soon as they see themselves reflected in a mirror and touch at that point: they understand they are theirs and have a small mark on their foreheads.

The test may seem trivial for Homo sapiens, but it is not at all for the other species. Recognizing that the reflex is one's own image has a significant meaning: it implies that the animal has self-awareness, that it understands that it is a different individual from others. To date, science has shown that not many people possess this ability: among them the great apes and dolphins, two types of mammals whose extraordinary intelligence is under the magnifying glass for some time, but also elephants and magpies (and macaques can learn).

Self-aware animals. Until a decade ago the restricted club included only cetaceans and primates. The list was lengthened in 2006, after three pachyderms from a New York zoo passed the mirror test, further reversing the old vision that considered animals as automatons driven by instinct alone.

In 2008 it was then the magpie's turn, not without a touch of surprise. In fact, birds show features that were previously thought to require the neocortex of mammals, that is the most recently developed part of the brain and considered the seat of higher cognitive functions. The birds do not have the neocortex, but it is theorized that they have in any case had a parallel evolution of consciousness.

The gorillas no. Chimpanzees, orangutans and children over the age of two have passed their mirror tests. But as can also be seen in the video, the gorillas, strangely, have failed. The reason is perhaps that these anthropomorphic monkeys, in nature, never look into each other's eyes to avoid tensions, and the vision of an apish image, which in principle may seem of another individual, may have inhibited the gorillas.

Deepening: animal consciousness

Unity is strength. Several studies show that species that have passed the mirror test show a high empathy that drives them to help group members. Being aware of oneself would allow to form more cohesive communities, dominating the subjects less inclined to social relations and collaborating to acquire food and power.