Duquesne University's 'puppy dog eyes' study among most influential of 2019

A research paper that studied how “puppy dog eyes” evolved to help dogs communicate with humans was ranked as one of the top 100 most influential studies of 2019.

The paper, co-authored by Anne Burrows, a biological anthropologist in Duquesne University’s Department of Physical Therapy, ranked 27th in the Altmetric Top 100. The ranking was out of more than 2.8 million papers published this year, according to a press release.

When the paper was published in June in the Proceedings of the National Academy of Sciences, it was instantly popular. Burrows said after publication in June, she was fielding interviews from media outlets around the world, waking in the early hours of the morning and staying up past midnight to speak with reporters in different time zones. She said it was “blissfully overwhelming.”

The Altmetric Top 100 recognizes research that generated “significant international online attention and discussion,” according to a press release. Among the papers named, topics included climate crisis, artificial intelligence and vaccination.

“Those sorts of topics, those have tremendous, real impact on peoples’ lives,” Burrows said. “And of course dogs impact our lives also, but the leagues of other works that we’re in company with is very surreal.”

An expert on the evolution of primate facial expressions, Burrows said she was drawn to the study as part of a much larger research agenda into human evolution.

Burrows and her colleagues had been studying mostly primates, including how the facial muscles of humans contract more slowly than other primates — which she said is likely related to the development of speech.

But humans are also unique in that they are the only species that has domesticated others, Burrows said. For this reason, she and her colleagues decided to examine some domesticated animals, including dogs.

“It all boils down to who we are as humans and what makes us unique as humans on this planet,” Burrows said.

The researchers examined dogs’ facial muscles while studying the species’ evolution, finding that while domesticating dogs, humans may have gravitated toward canines that have a specific muscle that allows them to raise their inner eyebrows. This eyebrow movement allows dogs to communicate with humans through facial expressions, the group said.

Burrows said the paper has fueled ongoing follow-up research, as well. She and the other report authors are now examining how the facial muscles in dogs differ from wolves.

“We have different disciplines working together, and when you do that, you learn so much,” she said.