If you are lucky enough to have a dog in your daily life, you have probably more than once had the impression that it was smiling: mouth open, teeth showing and lips pulled back. Some animals, such as the quokka (Setonix brachyurus), even wear a permanent smile. However, be careful, behind the apparent simplicity of a turned-up snout or a half-open mouth lies a much more elusive palette of animal emotions than our anthropomorphic interpretations suggest.
The illusion of the jovial dolphin
The bottlenose dolphin (Tursiops truncatus), this emblematic cetacean of the oceans, perpetually displays what seems to us to be an affable smile. The characteristic curvature of its rostrum, forming what appears to us as an eternal smile, has long fueled fantasies of an emotional intelligence close to our own. Yet, this expression is only an anatomical particularitya simple natural curvature of his jaw.
This distinctive physiognomy, the result of a long adaptive evolution, does not necessarily reflect a particular emotional state. Morphological studies demonstrate that this anatomical configuration, the result of millions of years of evolution, responds above all to survival imperatives : hydrodynamic optimization, efficiency in prey capture and adaptation to the constraints of aquatic life.
Italian and French researchers have nevertheless observed in this study published in October that these marine mammals more frequently present this typical expression during their playful interactions with their peers.
The authors point out, however, that the smile of these animals can actually serve several purposes, including a very important one: defense. In certain contexts, this “smile” can signal a form of warning or hierarchical positioning within the group.
Between dogs and cats
In 2017, a team of British researchers, led by the University of Cambridge, undertook an analysis of canine facial expressions, published in the magazine Scientific Report. They came to this conclusion: the interpretations we make of the expressions of our closest companions are not always the most appropriate. What we commonly interpret as a “smile” in dogs isis generally an indicator of anxiety or stress. Through this facial gesture, the animal can try to calm down or appear submissive in the face of a situation that it finds stressful.
Felines, for their part, remain more enigmatic. In this studyalso carried out in 2017, researchers looked at the case of the domestic cat (Felis catus). By adapting algorithms initially designed for the analysis of human facial expressions, these researchers have developed a tool allowing objectively decode the subtleties of feline expressions.
Their work highlighted an emotional repertoire including fear, anger and frustration (no, your cat is not indifferent all the time, despite its pout), but no manifestation resembling a smile.
When a man projects his emotions
Research on great apes offers particular insight into the origin of our facial expressions. The primatologist Frans de Waal devoted his work to the study of the different meanings of the simian “smile”. This open-mouthed expression, observed in particular during times when these animals are playing, would constitute an evolutionary precursor to the human smilewithout carrying the same emotional charge.
Greg Bryant, a cognitive scientist at UCLA (University of California Los Angeles), compares our tendency to interpret these animal expressions as smiles to the phenomenon of pareidolia. The same one which consists of perceiving familiar shapes, often faces, in random and ambiguous visual stimuli. In other words, it’s this natural tendency we all have to see faces in clouds, in textures, or even in everyday objects.
Marc Bekoff, evolutionary biologist and animal ethologist, urges caution, particularly in the interpretation of canine expressions : “ To understand a dog’s expression, we must consider the overall context: who is present? What is happening around him? » This excessive anthropomorphization can even turn out to be harmful to our pets. Bryant emphasizes that a dog expects his owner to assume a leadership role, not an egalitarian relationship that could generate anxiety in him. Animal facial expressions, as charming as they are, therefore deserve an informed and contextualized reading, far from human emotional projections.
- What appears to be a smile in animals, such as dolphins or dogs, is often an anatomical feature or indicator of stress, not an emotion of joy.
- Unlike dogs, cats’ expressions reveal emotions like fear or frustration, but no equivalent to smiling.
- Interpreting animal expressions as human can lead to errors and hinder understanding of their true needs.
