Do Dogs Really Smile? Scientists Found Dogs Evolved a Special Eyebrow Muscle

The post Do Dogs Really Smile? Scientists Found Dogs Evolved a Special Eyebrow Muscle first appeared on Crafting Your Home.

If you’ve ever watched a dog raise its eyebrows, widen its eyes, and stare at you with an unmistakably pleading expression, you may have wondered whether your dog is trying to communicate something.

Scientists have found that dogs have a distinctive facial muscle that lets them raise their inner eyebrows. A 2019 study comparing dogs and wolves found that the muscle, called the levator anguli oculi medialis (LAOM), was consistently present in the dogs examined but was absent or much less developed in the wolves examined. The researchers suggested that the expression may have helped dogs communicate with humans during domestication.

Here are seven things scientists have learned about those famous “puppy dog eyes.”

Dogs really can raise their inner eyebrows.

The 2019 research identified the LAOM muscle as being responsible for producing this movement. Researchers found that dogs used the expression more frequently and more intensely than wolves in their behavioral observations.

The eyebrow movement can make dogs look more puppy-like

The researchers described the movement as increasing paedomorphism, meaning it makes an adult animal look more juvenile or baby-like. The scientists proposed that this could have encouraged a nurturing response from humans.

Dogs appear particularly skilled at communicating with humans.

Research comparing young dogs and wolves has found that dog puppies tend to be more attracted to humans, make more eye contact, and follow human gestures more effectively than wolf puppies.

Scientists don’t think dogs literally “smile” like humans.

Dogs can make facial expressions that may accompany positive or relaxed states, but you shouldn’t automatically interpret a dog’s facial movements using human emotional categories.

A dog showing its teeth, for example, can mean very different things depending on the context. Body posture, ears, tail position, and the situation all matter.

The famous eyebrow-muscle theory has been challenged.

But newer research has complicated that explanation.

Another 2024 study found that coyotes have a well-developed LAOM muscle comparable to that of domestic dogs. The researchers suggested that the muscle may be an ancestral trait that was reduced or lost in gray wolves rather than something that evolved exclusively in domestic dogs.

Dog facial muscles may work differently from wolf muscles.

Scientists have also found differences in how some facial muscles function.

The researchers cautioned that the sample was small, so the findings need to be interpreted carefully. Still, the work adds another layer to how domestication may have changed canine facial communication.

Human preferences may have influenced dogs’ expressive faces.

Earlier research found that dogs displaying more puppy-like facial characteristics were selected more quickly for adoption from shelters. The researchers interpreted this as evidence that human preferences can influence selection for facial traits.

The 2019 eyebrow-muscle study similarly proposed that dogs capable of producing particularly expressive facial movements may have gained an advantage around humans.

So, Do Dogs Really Smile?

Not in exactly the same way humans do.

But scientists are still debating how that ability evolved. The original research suggested the muscle was a distinctive result of domestication, while newer studies involving coyotes and other canids suggest a more complicated evolutionary history.

One thing is clear: when your dog looks up at you with those enormous eyes and raised eyebrows, you’re seeing a real physical expression, not just something humans invented in their heads.