You wouldn’t say this: Dog breeds with smaller brains relative to their bodies are more intelligent – Earth – Science and Technology

In wild mammals, it is usually the case that the larger their brain relative to their body, the more intelligent they are. The exact opposite applies to domestic dogs.

Working dogs, which have a smaller brain in relation to their body, are generally more intelligent than smaller breeds, where the opposite is true.

A larger brain relative to body size does not automatically mean a smarter dog, a new study suggests. TASR informs based on the report of the journal Biology Letters and the Live Science server.

In wild mammals, it is usually the case that the larger their brain relative to their body, the more intelligent they are. The exact opposite is true for domestic dogs, according to a new study by an international team of scientists from Switzerland and France, published in the journal Biology Letters.

In the study, researchers measured the volume of 1,682 skulls of adult dogs of 172 breeds stored in the Natural History Museum in Bern, Switzerland. They then calculated the relative intracranial volume – the ratio of the size of their brain to their body. In the research, they also included 14 behavioral traits listed in the C-BARQ questionnaire, the most widely used standardized questionnaire for measuring trainability, demanding attention, aggressiveness and other characteristics of dog breeds.

The study showed that breeds with a smaller relative intracranial volume, i.e. a smaller brain in relation to the body, are better trainable. This category mostly includes working dog breeds, such as the Siberian Husky, Pyrenean Mountain Dog or Rottweiler. Working breeds tend to perform demanding tasks requiring cooperation with people, for example searching for people buried in debris or avalanches or guiding the blind.

Previous research has found that working breeds have better executive functions than other dog breeds, especially behavioral control and short-term memory. The reason is the different internal structure of the brain of large breeds compared to small breeds, according to Ana Balcarcelová, the lead author of the study from the Institute of Evolutionary Sciences in Montpellier, France.

Smaller breeds with higher relative intracranial volume show higher levels of timidity, aggression, separation anxiety and attention seeking. The scientist believes that the reason may be the original purpose for which these breeds were bred – as companions for people.

The researchers next plan to focus on studying the shape and functioning of the brains of dog breeds. The different shape of the cerebral cortex, the part responsible for higher brain functions, could explain the differences in the behavior of different breeds and types of dogs. However, Balcarcelová cautions dog owners that the results of the study are not an automatic indicator of a dog’s intelligence, as each dog is unique.