This is the science behind puppy-dog eyes

Dogs have evolved certain facial muscles to communicate more effectively with humans, a study suggests

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A new study has revealed why we find certain facial expressions made by dogs, like sad puppy dog eyes, so irresistible.

Humans and dogs have developed a unique bond over 30,000 years of domestication and companionship that has allowed both species to accurately identify facial expressions in one another.

New research suggests that humans contributed to dogs’ ability to form facial expressions due to thousands of years of selective breeding.

It found that dogs have evolved facial muscles that are quick to respond, making communication with humans more effective.

This means that when your dog wants something, he can quickly adjust his facial expression to communicate that need faster than other domesticated animals, like cats.

These specific muscles have evolved in higher percentages in domesticated dogs compared to wolves, which dogs are descended from.

Professor Anne Burrows of Duquesne University, senior author of the study, presented the findings to the American Association for Anatomy in Philadelphia this week.

According to Science News, she said: “Dogs are unique from other mammals in their reciprocated bond with humans which can be demonstrated through mutual gaze, something we do not observe between humans and other domesticated mammals such as horses or cats.

“Our preliminary findings provide a deeper understanding of the role facial expressions play in dog-human interactions and communication.”

In humans, tiny muscles called mimetic muscles are used to form facial expressions. These muscles are dominated by fast-twitch myosin fibres that allow people to form an expression quickly but unable to hold it for long.

The researchers found that both dogs and wolves have the same facial muscles that are dominated by fast-twitch myosin fibres, but wolves have more slow-twitch fibres compared to dogs.

The study also suggested that humans chose to breed dogs based on facial expressions that were similar to humans, which have allowed communication between dogs and people to become more effective over time.

Prof Burrows and her colleague, Kailey Omstead, said that further research was needed to confirm their findings, and could lead to more information about the anatomical differences between dogs and wolves.