tranmautritam (CC0), Pixabay

Dog owners have often noticed that their pets are able to interpret the moods of their owners. Now science has demonstrated conclusively that dogs recognise emotions in humans. Maybe that is the real reason why dogs have become man’s best friend?

Dogs do that by combining information from their different senses. They use this information to form a mental representation of the emotional state of people, positive as well as negative. Earlier studies have demonstrated that by observing facial expressions and signs, dogs can use this information to recognise human emotions. But Dr Kun Guo, the University of Lincoln’s School of Psychology, points out that this behaviour is not the same as emotional recognition. Commenting on his research, Dr Kun says: “This is the first empirical experiment that will show that dogs can integrate visual and oratory inputs to understand or differentiate human emotion as dog emotion”.

Experiments were carried out by a team of animal behaviour experts and psychologists at the University of Lincoln, UK, and at the University of Sao Paulo, Brazil. In these tests 17 untrained domestic dogs were exposed to images and sounds conveying either positive or negative emotional expressions in humans and in dogs.

To avoid prior conditioning among the dogs, all the dogs in the experiment were unfamiliar with the procedure.  The languages spoken and the facial expressions were also new and unfamiliar to the dogs in the test. ”So, we wanted to see if the dogs could assess the emotional content of the human voices and whether they would actually discriminate the emotional information within them”, explained Natalia De Souza Albuquerque, a PhD student in experimental psychology.

Dogs Look at Your Face

The results, published recently in the Royal Society journal Biology Letters, reported that dogs spent much longer looking at the facial expressions which matched the emotional state of the vocalisation. This was true both human and other subjects.

According to De Souza Albuquerque: “What we found is that when dogs were hearing positive sounds they would look longer at positive faces, both human and dog. And when they were listening to negative sounds, they would look longer at negative, angry faces.”

The experiments demonstrate that dogs have the capability to use at least two different type of sensory information to identify and interpret emotional states of both humans and of dogs. This ability has previously been observed only in primates. The study indicates that the ability to identify mental states could be much more common among different types of animals than we have known until now.

The ability to combine emotional cues seems to be inherent to dogs. As a highly social species, this ability of dogs to detect emotions in humans, may have developed for a long time during their domestication by people over the generations. As the ability developed, it further amplified the speed of their domestication.

This leaves open several interesting questions: How about horses and cats? Can they read our minds too? And how about the relatives of dogs like wolves and hyenas?