Dogs can differentiate between happy and sad faces, new study suggests

Man's best friend knows how you feel, as scientists have found that dogs can distinguish between emotions in people's faces.

The University of Vienna's findings are the first direct evidence of its kind that the animals possess the ability to read and respond to positive and negative emotions.

Researchers used machine learning to analyse brain scans of 12 border collies ​as the animals viewed images of human ‌faces displaying different emotions.

Brain regions in the dogs linked to higher cognitive functions and reward processing - the temporal cortex and caudate nucleus - ​were found to have been activated only by images of happy strangers.

When shown images of angry, fearful and sad emotions, those regions did not produce a response.

The researchers then looked at responses across the whole brain of the collies, and found distinct activity patterns that differentiated fear from anger ‌and sadness.

"To the best of our knowledge," the team said in its study, "this is the first evidence that dogs can distinguish between two human faces showing negative expressions.

"This suggests that the dog brain separates human facial expressions by valence, and shows separability among some negative human facial contrasts, particularly those involving fear."

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Senior author Laura Cuaya added that dogs "have evolved with us to understand our expressions and cooperate with us, and recognising that ⁠can change how we communicate with and ​care for them".

The ​researchers next plan to investigate how dogs ​integrate other cues, including body language, voice nuances and ⁠scent, to interpret the humans around them.

The study, published in iScience on Monday, acknowledges "several limitations," noting that border collies were found to be highly skilled at following social cues compared to other breeds, and that the limited sample size was shown static images rather than moving faces.

Researchers added that the 12 participants ​in the study were all pets from loving ​families, and cautioned that dogs outside such environments may respond to human emotional cues differently.

(c) Sky News 2026: Dogs can differentiate between happy and sad faces, new study suggests