Dogs can identify the happy and angry faces of humans with remarkable accuracy, scientists have discovered.
The Los Angeles Times reported that a new experiment proved for the first time that an animal can correctly identify the expressions of humans. Evidence generated by the study, published in the latest issue of the journal Current Biology, also showed that beyond identifying expressions, dogs can correlate expressions with their correct emotions as well.
"We’re mostly interested in what’s going on in the heads of animals," said lead author Corsin Müller, a cognitive biologist at the Messerli Research Institute, University of Veterinary Medicine in Vienna. "Most of this is about how we keep them and how we treat them. What sort of conditions do the animals need to live happy lives?"
Müller and his colleagues devised a test wherein 11 dogs — nine border collies, a sheltie, and a fox terrier — were placed in front of a touch screen showing two faces — one happy, one angry.
The dogs were divided into two groups. One group received a treat whenever they chose the happy face, while the other group was rewarded for choosing the angry face. Past studies had done similar things, but Müller
told The Verge that in this experiment they controlled for error much more strictly by using pictures that showed just part of the faces in addition to full pictures.
"[With the past studies] we're not sure whether they discriminated the face based on human expression. The very simple explanation is the dogs were just identifying teeth," he said. "They seemed to realize that the smiley eyes have the same meaning as a smiley mouth and angry eyes have the same meaning as an angry mouth."
In the end, the team discovered that the dogs completed their tasks with 70- to 80-percent accuracy. As an interesting side note, dogs that were trained to identify angry faces learned slower that those trained to look for happy faces, suggesting that "an angry face is something they wouldn’t want to approach and touch."
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