It turns out that dogs and wolves can both tell when something is unfair, and refuse to cooperate if they think they’ve been cheated. This lends support to the idea that the ability to judge equity may have evolved predominantly within group living species.
There had been hints that dogs were able to know if they had been treated unfairly when compared to other dogs, but no one was sure if this was a product of domestication, or a more inbuilt sense. This led scientists from the University of Veterinary Medicine, Vienna, to explore whether not only dogs but also wolves are able to tell when they are being short-changed.
The researchers tested the pairs of dogs and wolves to see how they would react to being cheated. In the first set of experiments, they trained the canines to push a buzzer with their paw for a reward. With the animals in separate cages, but able to see each other, they would reward one dog for correctly hitting the button, but not the other. The one who didn’t get any treats eventually stop participating and gave up. This was true for both wolves and dogs.
In the second set of experiments, the set-up was effectively identical, but rather than giving the test dog no reward for correctly pressing the buzzer, the researchers instead gave them a treat of lower quality than the one given to the other animal. Again, they found that the dogs and wolves given the poor treat ceased cooperating, and refused to participate.
“This showed that the fact that they themselves had not received a reward was not the only reason why they stopped to cooperate with the trainer,” explains Friederike Range, co-author of the study in Current Biology. “They refuse to cooperate because the other one got something, but they themselves did not.”
This, therefore, puts both dogs and wolves into the same group as some primates, and, as we learned earlier this week, ravens too. This select group of critters all seem to show the ability to recognize when they are being cheated and then react accordingly. In a famous experiment with capuchin monkeys, the primate that got the dud bit of cucumber literally threw it back at the researcher, while ravens held grudges against those who cheated them for up to a month later.
This all seems to point to the idea that having a sense of fairness probably has something to do with sociality, as all the animals shown so far to have it live in groups. This means that the animals all have to cooperate with other remembers of their species, and so in this situation, the notion of fairness and reciprocity is hugely important.