Social or non-social, it’s imperative for any living species to be able to mentally consider and assess quantities, and discriminate accordingly. This is one of the most important skills for animals mostly living in the wild, and especially useful for carnivores. Animals that hunt other animals must be able to determine whether their will be outnumbered by their enemies or not. It turns out that dogs might have lost this ability long time ago.
Researchers at the Messerli Research Institute at the Vetmeduni Vienna have analyzed canines and wolves to see if they are able to discriminate well between different quantities, and the results of the study show that wolves are much better at the vital task that can potentially save their lives when living in the wild. The results of this research have been published in the journal Frontiers in Psychology .
People and animals have been shown to discriminate between quantities. Lions, chimpanzees and hyenas, for example, will only approach a group of attackers if their own group outnumbers that of the intruders. These animals use numerical information to make decisions about their social life. Scientists believe that dogs have possibly lost this skill, or a predisposition for it, during domestication.
Testing numerical competence
In 2012 , Friederike Range and Zsofia Virányi from the Messerli Research Institute at the University of Veterinary Medicine Vienna showed that wolves are capable of discriminating between different food quantities. In their present study, they asked whether dogs also possess this skill or if this form of numerical competence was lost through domestication.
For the study, Range and her colleagues from the Department of Comparative Cognitive Research tested 13 crossbreed dogs raised at the Wolf Science Center in Ernstbrunn. The animals are living there together in different packs. The researchers tested the dogs for their quantity discrimination skills by presenting pieces of cheese. Those pieces were sequentially placed into two opaque tubes – one on the left and another on the right side. Eventually, the dogs had to decide which tube contained more cheese pieces than the other. By pressing the correct buzzer, the dogs were rewarded with cheese from the respective tube. Furthermore, the dogs did not see the person placing the cheese into the tubes, which excludes the human influence as a factor.
“We deliberately performed the test in such a way that the dogs never saw the full quantity of food at once. We showed them the pieces sequentially. This allows us to exclude the possibility that the dogs were basing their decisions on simple factors such as overall volume. The dogs had to mentally represent the number of pieces in a tube,” explains Range, one of the authors of the study, in the press release.
Dogs performed worse than wolves
Range and her colleagues compared the results of the wolf test with those from the dog test. The comparison showed that dogs were unable to discriminate between difficult comparisons such as two pieces of food versus three or three pieces versus four. The wolves, in comparison, fared much better.
“Dogs are better able to discriminate the quantities of food when they can see them in their entirety. But this requires no mental representation,” added Range.
Numerical competence lost with domestication
Range and her team are now investigating why the dogs performed so poorly in these tests. Is it because they have difficulties processing numerical information or is it their lacking ability for mental representation? It is possible that one of these skills was lost over the course of domestication. Human beings could be to blame.
“Compared to wolves, domestic dogs no longer have to search for food on their own. They have a secure place to sleep and even mating decisions are made by people. Dogs are thus excluded from natural selection,” Range explained.
- Friederike Range, Julia Jenikejew, Isabelle Schröder, Zsófia Virányi. Difference in quantity discrimination in dogs and wolves. Frontiers in Psychology, 2014; 5 doi: 10.3389/fpsyg.2014.01299
- Utrata E1, Virányi Z, Range F. Quantity Discrimination in Wolves (Canis lupus). Front Psychol. 2012 Nov 16;3:505. doi: 10.3389/fpsyg.2012.00505