Dogs and wolves have the same sense of injustice, new research show. This behavior is a property that dogs probably inherited from a common ancestor with the wolf, rather than something that was introduced when the dog was domesticated, the researchers argue.

Wolves recognise inequity similar to dogs and exhibit aversion against it. Photo: Rooobert Bayer

The fact that we people generally have a sense of inequality or injustice is clear, it has been an evolutionary advantage to facilitate group cooperation and cohesiveness. Earlier research has shown that our primate cousins, e.g. chimps, also have a sense of injustice. And in 2008, this very same ability was seen in dogs.

In a new study published in the scientific journal Current Biology, researchers have found that even wolves have this sense of “injustice” built in.

Two animals of either wolves or dogs were allowed to push a button to receive food. One of each were placed within an enclosure together with a ‘food-machine’ right next to each other.

Sometimes, both of them received food, and sometimes only the dog was fed. At those times only one of the animals were feed, the frustration over this maltreatment was clearly evident in its neighbor.

The higher the social status of the dogs and wolves that did not receive food, the more dissatisfaction they showed. This frustration was not shown to the same extent when a wolf or dog stood alone and pushed the button without receiving food.

Furthermore, the researchers were able to show that the dogs showed a kind of qualitative injustice, which in this case meant frustration when the food portions were smaller in comparison to the food portion its pal in the enclosure next door.

Jennifer L. Essler et al. Domestication Does Not Explain the Presence of Inequity Aversion in Dogs DOI: