Centuries of domestication have unintentionally changed your dogs eyebrow anatomy, making their faces easily readable to people, a new study says.
When your dog looks up at you, they will often raise their inner eyebrow muscle to make their eyes look larger and more appealing.
The research compared the anatomy and behaviour of dogs and wolves, allowing a comparison between the two, showing dogs facial anatomy had changed over many thousands of years to allow for better communication with humans. The study found that whilst the facial muscles of both dogs and wolves was similar, the muscles around the eyes differed. Dogs have a small muscle, enabling them to intensely raise their inner eyebrow, while wolves do not have this.
It is suggested by the authors of the paper that the raising of the inner eyebrow triggers a nurturing response in humans because it makes the dogs eyes look to be larger and resultingly more infant like, whilst also closely resembling a movement produced by humans when they experience sadness.
The research team was led by comparative psychologist Dr Juliane Kaminski at the University of Portsmouth, and included a team of behavioural and anatomical experts in the UK and USA. The research is published in the Proceedings of the National Academy of Sciences journal.
Kaminski, J., Waller, B. M., Diogo, R., Hartstone-Rose, A., and Burrows, A. M. (2019) Evolution of facial muscle anatomy in dogs. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1820653116.