By Dr. Becker
Have you ever wondered how your dog knows it's you coming home after a long day at work, or an evening out? How does she know, as you come through the door that you're not some scary stranger invading her territory?
It could be she hears familiar "coming home" sounds, like the garage door opening as you pull into the driveway. Maybe she recognizes the hum of your car's engine, or your footsteps approaching. Maybe she catches a whiff of your personal scent as you open the door.
Or… perhaps she simply recognizes your face.
For social animals that live in groups as humans and dogs do, it's important to be able to tell one individual in the group from another through facial recognition. But until recently, the aptitude for recognizing facial features was presumed to be a quality that only humans and possibly primates possess.
As it turns out, this highly developed skill is one we also share with our canine companions, which makes sense, since it's an established fact that faces and eye contact play an important role in human-dog communication.
Researchers at the University of Helsinki Test Facial Recognition Abilities in Domestic Dogs
In a recent study published in the journal Animal Cognition,1 researchers at the University of Helsinki, Finland, set out to examine facial recognition in domestic dogs, using pictures of faces on a computer screen. Facial inversion effect (a fancy term that means faces are harder to recognize when they're upside down) and responses to personal familiarity were tested using eye movement tracking.
The study included 23 pet dogs and 8 kennel dogs, and the question the researchers set out to answer was, if dogs are not trained to recognize faces, are they able to see faces in the pictures, and do they naturally look at familiar and strange faces differently?
Among their findings, the researchers discovered that dogs are more interested in the faces of other dogs than human faces.
Not surprisingly, dogs who live with families are more responsive to human faces than dogs living in kennels, and are more observant of familiar rather than unfamiliar human faces.
The dogs also showed great interest in the eye area, which according to the researchers suggests they perceive images representing faces.
Can Dogs Identify Faces Even When They're Upside-Down?
The study also analyzed the dogs' responses to faces that were shown to them upside down, because some species do not process inverted faces the same way they process faces that are right-side up.
Humans have the ability to quickly and accurately identify normally oriented (right-side up) faces because we are instinctively able to identify faces in a different way than we identify other types of objects. We recognize right-side up faces as complete structures rather than as a collection of parts. But when faces are upside down, we must perceive them as we do other objects, which is as individual parts rather than as a complete structure.
According to the University of Helsinki study, dogs also have more difficulty identifying faces that are inverted. However, since they spend a lot of time looking at the eyes in both normally oriented and upside-down faces, it suggests they do recognize the objects as faces regardless of orientation.
It's Official: Your Dog Knows Your Face!
The overall results of their study indicate that dogs – like humans and primates – are indeed capable of facial recognition.
"Dogs are able to see faces in the images and they differentiate familiar and strange faces from each other," say the researchers. "These results indicate that dogs might have facial recognition skills, similar to humans."