Dogs come in so many different shapes, colors, and sizes and you may wonder: Do dogs recognize dogs as dogs just by seeing them?
A team of researchers wondered what different dog breeds think of each other. They posed questions like: What do Pugs think of Afghan Hounds? Can dogs identify other dogs solely by appearance? If you take their powerful sense of smell is taken out of the equation, would a dog still know another dog when he sees one?
In a study published in the journal Animal Cognition in 2013, researchers enlisted 9 companion dogs as study subjects. All dogs had basic training and extensive experience with both dogs and humans. The study subjects were composed of a Border Collie, a Labrador, and mixed breed dogs to ensure that the doggie participants did not look the same.
The research setup was quite simple: the dogs were shown two screens, one on the right and one on the left with a divider in between. In each trial, two images appeared simultaneously on both screens, and the dogs were cued with a click and rewarded with a treat for approaching the “correct” screen.
Creating a Common Language
To find out if dogs could identify dogs based on appearance alone, the researchers had to create a common language with the dog subjects first.
During three training sessions,the dogs received a treat only when they approached the screen that had a picture of a dog’s face. The same dog picture was used throughout the training sessions while the other screen was either all black, all blue, or had a picture of a cow’s face.
The dogs were not given treats if they approached any of the non-dog pictures.
To qualify, the dogs had to approach the correct image 10 out of 12 times in two consecutive sessions. Amazingly, all nine dogs succeeded thus securing the common language.
During the main test, the study subjects were presented with a wide variety of unfamiliar dog faces along with unfamiliar non-dog faces.
Just like in the training sessions, dogs had to approach the correct image – the one showing a dog’s face – to get a treat. This task wasn’t easy as the dog images now included dogs’ of vast morphologic diversity in shape, color, size, head shape, ear position, and more. On top of that, the dog images were also paired against a wide range of non-dog faces including human faces, cats, sheep, gerbils, cows, rabbits, reptiles, birds and more.
Despite the difficulty of the task, the dogs succeeded in identifying which images were dog faces. Some dogs, like Babel, Bag, Cyane and Vodka, were able to do the task quite quickly, taking fewer sessions to approach the required 10 of 12 dog images.
Bahia and Cusco on the other hand, were slower on the uptake and took more sessions to distinguishdog faces from non-dog faces. But this does not mean that Bahia and Cusco don’t know a dog when they see one. The researchers note that a number of factors — like dog personality, learning styles and strategies, and motivation — can affect a dog’s behavior and performance, especially when it comes to this type of task.
The study suggests that despite their random and varied looks, dogs can identify other dogs by sight alone. It was however impossible to pinpoint exactly which features dogs look for in identifying a dog as a dog.
Image source: Autier-Dérian et al.
Source: Scientific American