Dogs have evolved to give us 'puppy eyes' University of Portsmouth has found

WHEN man’s best friends pull puppy-dog eyes at their owners they’re undoubtedly after an extra treat, walk or a bit of affection.
Picture: SuppliedPicture: Supplied
Picture: Supplied

Now researchers at the University of Portsmouth have revealed that dogs have developed specific muscles around their eyes in a bid to try and melt hearts.

Experts have found dogs have a small muscle which allows them to raise their inner eyebrow, triggering a nurturing response in humans. The movement makes the dog’s eyes appear larger, more infant like, and imitates humans when they are sad.

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The research team, led by comparative psychologist Dr Juliane Kaminski, at the University of Portsmouth, included a team of behavioural and anatomical experts in the UK and USA.

Dr Kaminski said the strong desire to look after your tail-wagger is achieved by the result of this simple muscle movement and gives dogs a selection advantage over others.

‘The evidence is compelling that dogs developed a muscle to raise the inner eyebrow after they were domesticated from wolves,’ Dr Kaminski said.

‘We also studied dogs’ and wolves’ behaviour, and when exposed to a human for two minutes, dogs raised their inner eyebrows more and at higher intensities than wolves.

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‘The findings suggest that expressive eyebrows in dogs 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.’

The expression has such a powerful effect on humans, yet the muscles that control the eyebrow movement are so thin you can see through them.

Co-author and anatomist Adam Hartstone-Rose, at North Carolina State University, USA, said it was ‘remarkable’ that the social interaction has led to such a quick change in evolution.

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The only dog species in the study that did not have the muscle was the Siberian husky, which is among more ancient dog breeds.

An alternative reason for the human-dog bond could be that humans have a preference for other individuals which have whites in the eye and that intense eyebrow movements expose the white part of the dog’s eyes.