We should smile at our dogs - a new scientific study reveals why

A recent scientific study has delved into the inner workings of a dog's brain when it encounters a human smile or frown. Researchers examined 14 dogs as they were scanned in a brain scanner while viewing pictures of people's faces. Happy, smiling faces triggered activity in an area of the brain linked to rewards, the same region that activates in humans when we experience positive emotions like winning or receiving praise.

This reward circuitry is responsible for the thrill or high we feel when we achieve something or receive positive feedback. The same brain region lights up in dogs when they anticipate a tasty treat or recognize a familiar person. Laura Cuaya and Raúl Hernández-Pérez, researchers at the University of Vienna, found that dogs recognize happy faces, even those of strangers, as having positive value.

While dogs can differentiate positive emotions from negative ones, they don't seem to distinguish between various negative emotions. Cuaya and Hernández-Pérez, a canine-cognition research duo, have studied how dogs interpret human language and behavior, involving their own border collies in the research. Their findings, published in the journal iScience, suggest that dogs have developed unique social abilities through domestication that allow them to understand and cooperate with humans.

Cuaya and Hernández-Pérez recommend smiling at dogs, even random ones on the street, to reinforce a positive relationship.