An article on Pet Dog Pals recently made me consider how well dogs can recognize human faces in images. What does the world look like through the eyes of dogs? What do they recognize and how do they perceive their surroundings? The growing number of research results enables us to understand the dog and its abilities increasingly better. The extent to which dogs are able to identify people in photographs has now been investigated in an interesting study.
Face recognition in humans
Most people are very good and quick at recognizing faces. Quickly identifying who you are and in what mood is an absolute necessity for social interaction. Even newly born babies show a tendency to pay more attention to faces than to other stimuli of the environment. In the course of our lives we are confronted with so many different faces in different emotional states that the brain even reserves a special area for processing faces.
We also reliably recognize faces in photographs. Those who have no limitations in recognizing faces can quickly identify friends in recent vacation photos and their respective moods. Whether dogs are also capable of this is an exciting question. After all, the close living together with humans has produced numerous special abilities of the four-legged friends. For example, they can detect and distinguish between negative and positive emotional facial expressions of humans.
To answer this question, researchers have investigated whether dogs recognize their owners in photographs. In this respect, some animals have their difficulties. For example, pigeons can recognize different objects presented to them on a two-dimensional photo. If, on the other hand, they are shown the faces of people, they are not able to identify them on two-dimensional photos.
Gate one or two
The subjects for the study consisted of 60 dog-holder pairs. To test the dogs’ abilities, the researchers developed a special test apparatus. On the left and right side of the test apparatus there was a photo, one of the owner and on the other side a photo of a stranger.
After the dogs had entered the test room, the photos on the wall were presented to them at the same time. After 10 seconds, two small curtains opened below the photos at leg level. Behind them stood either the owner or the stranger, matching the photo. The four-legged friends could then decide which of the opened curtains they wanted to go through. The scientists also determined in further passages, for which access the dogs without picture decided. The latter is necessary to find out whether the presented photos alone really have an influence on which access the dog chooses
Without any photos, the dogs without any system randomly chose the left or also the right trapdoor. So it was not that they preferred to access the trap door by means of olfactory information, for example, which led them to the owner. Even if the faces in the photos were not directly facing the dog, they did not often choose the open curtain behind which their owner was standing. However, when the face was directed straight at the dog and with a neutral expression, the dogs seemed to identify their owners. In this case, they significantly often chose to access their owner.
Interestingly, among the dogs tested, the males scored better in this task. A similar effect can be observed in toddlers. In one study, male infants showed better abilities and face recognition than female infants. This effect was reversed in adulthood (source).
According to the results, dogs seem surprisingly able to recognize their owners on photos. However, it is not clear whether they are aware that they are only looking at a two-dimensional image of the face. They may not be able to distinguish the image from a real three-dimensional face. According to previous findings, not many animals seem to possess this ability. It is possible that the long periods of domestication and living together with humans play a role in this. Now many open questions are still waiting to be answered, which the results raise. For example, it would be interesting to know to what extent dogs are able to recognize conspecifics or objects of the environment in photographs.