Dogs have bigger brains than cats because they are more sociable , while felines lead a lonelier existence. Researchers from the University of Oxford (United Kingdom) reached this conclusion after analyzing the evolutionary history of the brain of different mammals during the last 60 million years. As published by Susanne Shultz and her colleagues in the journal PNAS , there is a link between brain size and the degree of sociability of a particular mammal. Thus, the brains that have grown the most over time belong to monkeys, followed by horses, dolphins, camels and dogs. The work also shows that more solitary animals such as cats, deer and rhinos have hardly increased the size of their gray matter during the same period of time.
The study also shows that mammals with large brains tend to live in socially stable groups . "The cooperation and coordination required for group living is challenging, and over time some mammals have developed larger brains to meet these demands of socialization," concludes Schultz.
