For friends of man's best friend it will be difficult to accept: domestication has made dogs more stupid. This is the result of a new study (in English) of the University of Veterinary Medicine in Vienna, where researchers tested three groups of animals: 12 wolves raised in captivity, 14 dogs raised in the same way (in packs) and 12 domestic dogs. In three tests their ability to recognize communicative, behavioral and causal clues was evaluated.

Where is the food? Dogs know how to surprise when it comes to food and, even in this research, the tests consisted in guessing in which container food was hidden. In the communicative test a man indicated the right box while maintaining visual contact with the animal.

A wolf during a test. A wolf during a test. | Michelle Lampe / Wolf Science Center

Wolves and dogs were able to catch the clue and interpret non-verbal communication, arriving at the right box. The behavioral test was identical, but the man who indicated the box did not look directly at the animals and this made the difference: no animal, of any group, was able to recognize the clue.

Lost without man. In the causal test, in the absence of the man, the canids had to understand that the right box was the one that produced noise if moved. Only the wolves were able to complete the test, while the dogs - both in the herd and at home - remained dry-mouthed.

Image Trusted but equally intelligent companion? | Shutterstock

"The result suggests that domestication has influenced the understanding of the cause-effect mechanism of dogs, " commented biologist Michelle Lampe (Radboud University, Netherlands), who added that the study does not prove that wolves are inherently more intelligent of dogs, because, he speculates, "dogs are conditioned to receive food from humans, while wolves have to find it themselves."

The study suggests that wolves are as good as dogs at understanding humans, and this may give us some clues as to how wolves became dogs.