A group of cognitive neuroscientists have shown conclusively that dogs are able to differentiate between happy and sad human faces. Although a lot of research has been done during the past decade to investigate if animals have emotions and respond to emotional expressions from others, this is the first study which conclusively shows that pet dogs can discriminate emotions in human faces.
In this study, 20 pet dogs were presented with happy and angry human faces side by side. The dogs were divided into 2 groups: one of the groups was trained to touch happy faces with their nose while the other was trained to touch an angry face.
To eliminate the possibility that dogs would make decisions based on the differences between the pictures, the researchers split the pictures horizontally. This means that during the training phase, the dogs only got a view of either the eye region or the mouth region.
"We can rule out that the dogs simply discriminated between the pictures based on a simple salient cue, such as the visibility of teeth," said study author Corsin Müller, an animal behaviour researcher at Messerli Research Institute.
It was found that the dogs were able to select faces more often than what would be expected as random chance. The study published in the journal Current Biology showed that not only were the dogs able to identify emotions in human faces but were able to transfer what they have learned to identify emotions in new faces.
Ludwig Huber, senior author of the paper and head of the group at Messerli Research Institute, says, "Our study demonstrates that dogs can distinguish angry and happy expressions in humans, they can tell that these two expressions have different meanings, and they can do this not only for people they know well, but even for faces they have never seen before,".
The researchers intend to continue their research and explore how experience affects the abilities of dogs to recognize human emotions. Furthermore, they plan to study how dogs express emotions and how their emotions are affected by those of their owners.
REFERENCES AND FURTHER READINGS:
https://www.sciencedirect.com/science/article/pii/S0960982214016935
