Dogs produce more facial expressions when people look at them, according to new research from the University of Portsmouth. Scientists at the University's Dog Cognition Center are the first to find clear evidence. Dogs move their faces in direct response to human attention. Dogs don't react with more facial expressions to the sight of tasty food, suggesting that dogs produce facial expressions to communicate and not just because they're excited. Raising the eyebrows, causing the eyes to enlarge – so-called puppy dog eyes – was the most common expression of the dogs in this study.
The researchers studied 24 dogs of different breeds, from 1 to 12 years old. All were pets. Each dog was tied by a three-foot lead from a person, and the dogs were filmed through a series of exchanges, from the person facing the dog, to being distracted and with the dog's body turned away. The dogs' facial expressions were measured using DogFACS, an anatomically based coding system that provides a reliable and standardized measure of facial changes related to underlying muscle movement.
“We knew that domestic dogs paid attention to how attentive a person is – for example, in a previous study we found that dogs stole more food when a person's eyes were closed or they turned their backs. In another study, we found dogs that followed a person's gaze if the person had first made eye contact with the dog, so the dog knows that the shifting gaze is on them. “This study advances what we understand about canine cognition. We now know that dogs make more facial expressions when humans pay attention.”
