New research from the University of Vienna shows that dogs can understand human emotions better than scientists thought. In the study, scientists looked at the brains of pet dogs while they watched photos of people with happy, angry, fearful, or sad faces. The main finding is that dogs react strongly to smiling human faces, and their brains can tell the difference between fear and sadness.

This happened because dogs have lived with humans for thousands of years. Over this time, their brains have become better at recognising and reacting to human facial expressions.

Because of this, dogs may be very good at understanding people’s feelings just by looking at faces. The study suggests that when a dog looks at your face, it may notice much more than you think.