The surprising reason that dogs sometimes have 'sad eyes'

Most of us are aware of dogs pulling puppy dog eyes. Whether it’s refusing to give them a treat, or scolding them for making a mess, it’s a great way to make us feel bad for disciplining our pets.

According to a new study, dogs have actually evolved ‘sad eyes’ so they can communicate with humans and let them know they’re feeling down. And yes, it’s definitely effective!

The University of Portsmouth conducted this interesting study, discovering that dogs’ faces have changed over thousands of years for the benefit of human connection.

A spokesperson from the study said ‘Researchers found that the facial musculature of both species was similar, except above the eyes.'

‘Dogs have a small muscle, which allows them to intensely raise their inner eyebrow, which wolves do not.’

‘The authors suggest that the inner eyebrow-raising movement triggers a nurturing response in humans because it makes the dogs' eyes appear larger, more infant-like and also resembles a movement humans produce when they are sad.’

Read more: Dogs tilt their heads to the side when they look at you for the cutest reason

By comparing the behaviour and anatomy of dogs and wolves, researchers were able to see if there was a difference between wild and domesticated animals.

Turns out there is, dogs raised their inner eyebrow more often and at higher intensities when exposed to humans for two minutes, as opposed to wolves who did it much less.

Research lead Dr Juliana Kaminski said ‘The findings suggest that expressive eyebrows may be a result of humans' unconscious preferences that influenced selection during domestication’

‘When dogs make the movement, it seems to elicit a strong desire in humans to look after them.’

‘This would give dogs that move their eyebrows more a selection advantage over others and reinforce the 'puppy dog eyes' trait for future generations.’

So it turns out there’s a scientific reason for this after all, meaning it’s okay to feel less guilty next time your dog decides to flash you the puppy dog eyes. We’re on to them.