These Are the Happiest-Looking Dog Breeds, According to Science

Every dog parent wants to believe that their pup is content, but it’s not always easy to tell what our pets are really feeling — and looks can be deceiving. Depending on your dog’s breed, they may seem to be constantly grinning or permanently furrowing their brows. A new study published in Behaviour analyzed the facial expressions of 210 dogs to determine which breeds are the happiest-looking and which have a bad case of RBF (Resting, Er, Female-Dog Face).

Researchers examined 925 different facial expressions across 29 different breeds. The 210 dogs were filmed while they were relaxed, playful, and panting with their mouths open. 

The research team, led by Dr. Veronica Maglieri, specifically watched for how the different breeds expressed their “play face” — aka that open-mouthed, smiley expression that dogs make when they’re feeling playful. They catalogued the movement of facial muscles across the breeds.

“We found breeds like the Poodle and German Shepherd have a much more exaggerated, full version of the play face, whereas breeds like the Beagle have a very subtle, minimal version,” Dr. Maglieri explained in a statement.

In addition to Poodles and German Shepherds, Dr. Maglieri found that Basset Hounds, Czechoslovakian Wolfdogs, Rottweilers, and Pit Bulls were the most expressive — when they made their play faces, they almost looked like they were laughing. The highly expressive breeds used more facial muscles and tended to have more exaggerated expressions. 

On the other hand, the least expressive breeds included Beagles, Shih Tzus, Newfoundlands, Bull Terriers, and Akitas. Initially, the researchers expected to find that flat-faced breeds like Pugs and Bulldogs would be extremely inexpressive, because the structure of their faces only allows them to produce limited facial expressions. But those select facial movements include “lip corner pulls” and “mouth stretches,” which make those breeds look like they’re smiling. If you’ve ever seen a Pug’s goofy tongue lolling out of their mouth, then you get it.

The play face — also known as the Relaxed Open Mouth (or ROM) — isn’t just unique to domesticated dogs. In fact, it appears in many different carnivores, including wolves. It’s an evolutionary signal designed to indicate to other animals that they’re not being aggressive. It’s how, for example, dogs in the park convey that they’re just being playful and not actually looking for a fight. 

On LinkedIn, Dr. Maglieri explained that she used the data to create a tree-like diagram (known as a dendrogram) to examine how closely related different dog breeds are to one another and to wolves — based not on genetics, but on how different breeds activate their facial muscles. 

“This is a completely new approach: instead of asking ‘who descends from whom?’,  I asked ‘who moves their muscles in the same way?’,” she wrote. “The result is a functional tree that reveals communicative, rather than ancestral, distances, and the two do not overlap. This perspective suggests that artificial selection has not only shaped the external appearance of dogs, but also their facial expressivity, with potential implications for play communication and for how effectively different breeds can interpret each other’s intentions.”

The play face allows dogs to communicate with each other and with their humans, and it’s a useful tool for conveying intent. But if your Beagle or Newfoundland pup looks perpetually melancholy, don’t worry. Just because they don’t look as goofy and cheerful as a smiley Poodle doesn’t mean they’re any less happy.