Surely every dog owner knows this moment: the dog is sitting there, looking at you with his tongue out, his eyes slightly closed and the corners of his lips raised. It looks like the dog is smiling – sincerely, warmly, even humorously. Owners are often sure-footed: “My dog definitely laughs when I come home from work!” or “She knows when I’m joking – and she smiles.” But do dogs really smile the way humans do? Or is it a natural muzzle position that we just want to endow with emotional meaning?
Smiling is one of the most unique modes of nonverbal communication in humans. It’s a display of emotion, social connection, joy, irony. But do animals have something similar? And if so – do dogs consciously use smiling to communicate with us, or is it just a reflection of a bodily state? Modern science already has something to say about this – and partially confirms what we so want to believe.
Scientific research: is there a “smile” in dogs?
It turns out that dogs have at least one facial expression that is very similar to a human smile: a relaxed mouth, an open mouth with a raised tongue, raised corners of the lips, and a soft gaze. Many studies categorize this expression as “an expression of joy or increased comfort.” In particular, scientists at the University of Portsmouth who developed DogFACS, a system for analyzing canine facial expressions, found that lip lifting and muscle activity similar to those responsible for the human smile often accompany positive human interactions.
In addition, in 2017, researchers found that dogs showed higher facial expression activity specifically in the presence of people, not when they were simply receiving food. That is, smiling may not only be a physiological reflex, but also a social signal – an attempt to establish an emotional connection. This puts smiling in the category of communicative tools that dogs may have developed during cohabitation with humans.
Additionally, experiments have shown that dogs are able to mimic human emotions, including facial expressions. If a person smiles – a dog can “respond” with a similar expression. This is not necessarily a smile in the human sense – but it at least has the function of an emotional response and positive reinforcement.
The biological basis of emotional mimicry in dogs
To understand if dogs can smile, you have to look under their skin – literally. Dogs have muscles that allow them to move their lips, lift them, and change their muzzle expression. One key muscle, the levator anguli oris, is responsible for lifting the corners of the mouth, which creates the “smile” effect. Although these muscles are not as developed as in humans, they are sensitive enough to show emotional changes through the muzzle.
But even more important is the hormonal background. In moments of human interaction, a dog’s oxytocin levels rise dramatically – the same “love hormone” that causes feelings of warmth, affection and pleasure. And this hormone literally triggers body reactions – including relaxation of the muzzle muscles. Combined with conditions of comfort, safety and trust, this may well look like…. a smile.
And, of course, we shouldn’t forget about development. Dogs are the first animals to undergo millennia of domestication alongside humans. They didn’t just learn to understand our signals – they began to form their own, adapted to our expectations. So it’s likely that some of the facial expressions we interpret as “smiling” came about through the process of coexistence – because the dogs that seemed “emotionally expressive” were the ones that humans liked better and survived better.
Owner observation
Millions of videos online, thousands of stories on social media – and they’re all about the same thing: a dog that smiles, it seems. Someone writes that the dog “smiles toothily” every time he sees the leash. Someone – that the pet is “joking”, playing the role of the guilty. There are cases when the dog, hearing the laughter of the owner, also begins to open his mouth, grunt, “smile” and even imitate a “giggle”. Or is it just a coincidence? Is a dog really able to adopt and reflect our moods?
In many breeds, especially Labradors, Golden Retrievers, Border Collies, it is more common to notice “smiling” as a separate trait. This can be either an inherited feature of the muzzle or a learned behavior. Some dogs realize that certain facial expressions cause a positive reaction in people – more affection, praise, attention. So they repeat it as part of the interaction.
It looks very cute, but it also makes you wonder: are we seeing a real emotion or just a successful illusion?
Conclusions: what can we say for sure?
Dogs can exhibit facial expressions that resemble a smile – and in many cases, they are indeed expressions of joy, comfort, and friendliness. Scientific research supports this idea, pointing to a link between facial expressions, hormonal changes, and social interaction. However, not all “smiles” are the same. Some are the natural shape of the muzzle or the result of a physiological condition. Others are complex social signals that we can misinterpret.
Regardless, one thing remains undeniable: the human-dog bond is so deep that even a dog’s attempt to “smile” can be a genuine response to love, attention, and a shared history of millennia of trust. And perhaps that is exactly what the most genuine smile of all is.
