Facial expressions in dogs
Researchers from Walden University, Minnesota, have found that a range of emotions can be identified in dogs from changes in their facial expression.
Psychologist and research leader Dr Tina Bloom and her colleague, Professor Harris Friedman, discovered that volunteers were able to correctly spot when a dog was happy, sad, angry, surprised or scared.
The study involved taking photos of five-year-old Belgian shepherd dog and police dog, Mal. Each shot displayed Mal's face as different emotions were experienced.
Tools were used to trigger reactions. A jack-in-the-box was used to surprise Mal, which caused a wrinkled frown, and nail clippers – which Mal dislikes – caused the ears to prick up and eye whites to show.
Fifty volunteers were split into two groups according to their experience of dogs, and shown the photos.
The easiest emotion to recognise was happiness, as identified by 88 per cent of the volunteers. This was closely followed by anger, which was recognised by 70 per cent.
Surprise and disgust were two of the more difficult emotions to identify among the volunteers.
Dr Bloom and Prof Harris also found that those with minimal experience of dogs were better at identifying Mal's disgust and anger. The researchers believe that this is because dog owners are likely to associate the aggressive facial expression with playfulness.
"There is no doubt that humans have the ability to recognise emotional states in other humans and accurately read other humans' facial expressions," said Dr Bloom.
"We have shown that humans are also able to accurately – if not perfectly – identify at least one of the dog's facial expressions."
She added that humans often think of themselves as disconnected or even isolated from nature, but the study actually suggests that there are connections.
"And one of these [connections] is in the from of emotional communication."
In the future, Dr Bloom hopes to further research whether this type of empathy is something humans naturally share with all mammals.
The study has been published in the journal Behaviour Processes.
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