Good boy! Puppy dog eyes evolved just for you

Top dog: “We created this infant-like creature,” says scientist Juliane Kaminski.

Is your dog really your best friend? Or is it just manipulating you? A new study has identified eyebrow-raising muscles that help puppies to produce their most irresistible expressions.

If you have a pet dog, you already know the expression well. The eyebrows go up. The eyes go wide. And your heart melts.

Scientists now believe that dogs evolved to make their expressions cute for humans. A new study found two facial muscles in dogs that were not present in wolves.

These muscles are called the RAOL and the LAOM. They connect the ring around a dog’s eyes to either end of its brows. This is what allows dogs to raise their eyebrows at their human owners. The expression is often called “puppy dog” eyes.

The scientists believe that the muscles developed as dogs evolved from wolves. Early humans were more likely to look after dogs they felt sympathy for. Then, over time, dogs got better at evoking that sympathy.

“We prefer dogs with […] infant-like, large eyes,” explained Juliane Kaminski, one of the study’s authors, in The Times. “It triggers a nurturing response. We want to take care of this thing.”

Of course, dogs are also very good at responding to humans. If their owners are trapped and crying, for example, dogs will become upset and try to free them. This is known as the “Lassie hypothesis”.

Man’s best friend?

So, are we just being manipulated by 33,000 years of evolution? For a long time, people believed that humans were the only ones with the gift of consciousness. Animals do not think and feel; they react on instinct. If your dog looks sad, it is only because it has learned that this will get you to do what it wants.

But scientists are beginning to question this. A wave of new research suggests that animals are more aware than we first thought. Dogs are a great example. They produce the same relaxation hormone as we do when being cuddled. They also produce the same stress hormone if left alone for too long. Their bond with humans is real.

You Decide

  1. Will this news change how you react to your dog’s cutest faces?


  1. Write a short story through the eyes of a pet dog. How does it get what it wants? Include sensory language.

Some People Say...

“A dog is the only thing on Earth that loves you more than he loves himself.”

Josh Billings, US writer (1818-1885)

What do you think?

Q & A

What do we know?
Scientists found that six dogs had the LAOM muscle. Four wolves they studied did not. The RAOL muscle was less pronounced in wolves than in five of the dogs. The exception was a Siberian Husky, one of the most ancient dog breeds.
What do we not know?
The findings suggest that the muscles developed as dogs were domesticated. However, we do not know exactly when, or why, it happened.

Word Watch

New study
Published in PNAS, on Monday.
Dogs evolved from wolves through artificial selection. In other words, humans bred wolves with characteristics (such as, smaller teeth) that they wanted to keep.
Bringing out; making us feel or think something.
Wanting to care and protect.
A reference to a fictional dog called Lassie. Stories about Lassie usually involve her saving the day.
33,000 years
Scientists believe that this is how long ago dogs split from wolves.
The state of being aware of your surroundings.

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