What is behind those hard-to-resist puppy dog eyes? New research suggests that over thousands of years of dog domestication, people preferred pups that could pull off that appealing, sad look, and that encouraged the development of the facial muscle that creates it.
Today, pooches use the muscle to raise their eyebrows and make the baby-like expression. That muscle is virtually absent in their ancestors, wolves.
“You don’t typically see such muscle differences in species that are that closely related,” said Anne Burrows of Duquesne University in Pittsburgh, an author of the study released on Monday by the Proceedings of the National Academy of Sciences.
Photo: AFP
Dogs differ from wolves in many ways, from having shorter snouts to their different sizes and more expressive faces. Unlike wolves, dogs rely heavily on human eye contact, whether to know when someone is talking to them or when they cannot solve a problem, such as hopping a fence or getting out of the door.
Burrows and her colleagues examined the eye muscles in the cadavers of six dogs and two wolves. They found dogs have a meaty eye muscle to lift their eyebrows and make puppy dog eyes, but in wolves, the same muscle was stringy or missing.
The scientists also recorded 27 dogs and nine wolves as each stared at a person. Pet pooches frequently and intensely pulled back their eyebrows to make sad expressions, while the wolves rarely made these faces, and never with great intensity.
The researchers believe dogs, over their relatively short 33,000 years of domestication, used this eye muscle to communicate, possibly goading people to feed or care for them — or at least take them out to play — and people obliged.
Dog experts not involved with the study were impressed.
“The implications are quite profound,” said Brian Hare from Duke University, who edited the article.
These muscles almost certainly developed because they gave dogs an advantage when interacting with people, and people have been unaware of it, Hare wrote in an e-mail.
Evan MacLean at the University of Arizona said the findings were fascinating, but cautioned that the muscle difference could be an indirect effect of other changes.
Clive Wynne of the Canine Science Collaboratory at Arizona State University said: “Kudos to the researchers for thinking of a cool way to investigate an important aspect of dogs’ success” with humans.
However, he said in an e-mail that the study has a few snags, particularly the small sampling — only five dog breeds were examined and videos were mainly of Staffordshire bull terriers — and the lack of background information about each animal.
Burrows said she is planning follow-up studies to examine more breeds.
MONEY MATTERS: Xi was to highlight projects such as a new high-speed railway between Belgrade and Budapest, as Serbia is entirely open to Chinese trade and investment Serbian President Aleksandar Vucic yesterday said that “Taiwan is China” as he made a speech welcoming Chinese President Xi Jinping (習近平) to Belgrade, state broadcaster Radio Television of Serbia (RTS) said. “We have a clear and simple position regarding Chinese territorial integrity,” he told a crowd outside the government offices while Xi applauded him. “Yes, Taiwan is China.” Xi landed in Belgrade on Tuesday night on the second leg of his European tour, and was greeted by Vucic and most government ministers. Xi had just completed a two-day trip to France, where he held talks with French President Emmanuel Macron as the
With the midday sun blazing, an experimental orange and white F-16 fighter jet launched with a familiar roar that is a hallmark of US airpower, but the aerial combat that followed was unlike any other: This F-16 was controlled by artificial intelligence (AI), not a human pilot, and riding in the front seat was US Secretary of the Air Force Frank Kendall. AI marks one of the biggest advances in military aviation since the introduction of stealth in the early 1990s, and the US Air Force has aggressively leaned in. Even though the technology is not fully developed, the service is planning
INTERNATIONAL PROBE: Australian and US authorities were helping coordinate the investigation of the case, which follows the 2015 murder of Australian surfers in Mexico Three bodies were found in Mexico’s Baja California state, the FBI said on Friday, days after two Australians and an American went missing during a surfing trip in an area hit by cartel violence. Authorities used a pulley system to hoist what appeared to be lifeless bodies covered in mud from a shaft on a cliff high above the Pacific. “We confirm there were three individuals found deceased in Santo Tomas, Baja California,” a statement from the FBI’s office in San Diego, California, said without providing the identities of the victims. Australian brothers Jake and Callum Robinson and their American friend Jack Carter
CUSTOMS DUTIES: France’s cognac industry was closely watching the talks, fearing that an anti-dumping investigation opened by China is retaliation for trade tensions French President Emmanuel Macron yesterday hosted Chinese President Xi Jinping (習近平) at one of his beloved childhood haunts in the Pyrenees, seeking to press a message to Beijing not to support Russia’s war against Ukraine and to accept fairer trade. The first day of Xi’s state visit to France, his first to Europe since 2019, saw respectful, but sometimes robust exchanges between the two men during a succession of talks on Monday. Macron, joined initially by EU Commission President Ursula von der Leyen, urged Xi not to allow the export of any technology that could be used by Russia in its invasion