Can dogs tell if you are happy or mad? Most of us would like to believe so but can this belief be backed up by science?
Science is still undecided about the matter but there is a lot of evidence in favor of the idea.
A new study on the subject was published February 12 in the journal Current Biology. The research adds to the growing evidence proving that dogs can, indeed, tell our emotions. It has been found that dogs are able to distinguish between happy and angry human facial expressions.
Biologist Corsin Müller of the University of Veterinary Medicine in Vienna, Austria, and his colleagues tested 11 dogs of different breeds—including Border Collies, a Fox Terrier, a Golden Retriever, a German Shepherd, and others—using a touchscreen. They trained the dogs to touch either a happy face or an angry face in exchange of a treat.
The dogs were presented dogs with either the upper half or the bottom half of the faces to make sure that thepooches weren’t merely responding to a smile or the baring of teeth.
Emotions show on all parts of a human face, not just the mouth, says Müller.
“If you’re angry, a wrinkle between the eyes shows up,” he explains. The shape of the eyes can change too. This means that if dogs can really spot an emotion, they should be able to do so regardless of which part of the face they look at.
Once the dogs were trained, the researchers ran them through choice trials –the pooches had to pick between strange faces with either happy or angry expressions. The researchers presented the dogs with the top, bottom, or left half of a face – since previous studies found that dogs prefer to look at the left side of a face.
The dogs trained to pick out the happy faces could do so when presented with different halves of a face, as well as when presented with faces the pooches had never seen before.
The dogs trained to respond to angry faces were also able to pick out angry faces among the choices they were asked to make. But they tooka longer time to learn their task than the dogs trained on happy faces.
Müller thinks that the reason behind the delayis the dogs’ negative associations with angry faces. Perhaps the dogs think thought that angry faces meant they wouldn’t receive any pats, while happy faces meant a belly rub, he suggests.
Experience Or Domestication?
The researchers don’t yet know whether the dogs’ ability to distinguish the two expressions is because of their past experience or the result of the domestication process.
It’s not so surprising that dogs can tell facial expressions apart, Müller says. “Because they spend so much time with humans, they have a lot of opportunities to see human expressions.”
Marc Bekoff, a behavioral ecologist who specializes in canines at the University of Colorado, agrees. Humans and canines have made an incredibly tight connection over thousands of years together, says Bekoff, who wasn’t involved in the study. Over thousands of years, dogs have been bred for certain traits, and “one of the traits would be the ability to read us.”
The question now is whether dogs that spend a lot of time with people would be as good at picking up our expressions as dogs without a lot of people experience, Bekoff adds.
Müller plans to find out the answer to that question. He also aims to find out whether domestication played an important role in the dogs’ ability to read human expressions.
Source: National Geographic