Man’s best friend might be better at reading our faces than previously thought after Austrian researchers found evidence that canines can read the difference between happy and angry expressions.

In a study published in the scientific journal Current Biology, the dogs tested were shown a touch-screen display with a selection of human faces with emotions ranging from happiness to anger. The dogs were then rewarded with treats if they could successfully touch their noses to the correct emotion.

The eleven dogs tested, which included mix breeds, border collies, a fox terrier, a golden retriever and a German shepherd, were tested by biologist Corsin Müller and his colleagues in Vienna.

The test was made more difficult by limiting the on-screen faces to only their top or bottom half, to test the dogs ability to react to emotional cues and facial signifiers.

After training them, the dogs were given a series of choice trials, presented with a selection of entirely new faces, and asked to choose either the happy or angry emotions.

The researchers noticed that it took dogs longer to identify angry faces, and reasoned that this might indicate reluctance. The team also thought that dogs are quicker to identify happiness because a happy human being is more fun to be around.

As for whether this ability to read emotional states is a result of nature or nurture in unknown, but Corsin Müller says it’s not at all surprising.

"Because they spend so much time with humans, they have a lot of opportunities to see human expressions,” he said.  

The study claims that the findings are the first solid evidence showing that a non-human animal is capable of discerning the emotions of another species.