Dogs the brainiest of the pet world

BRAIN POWER: Simmo the cat yesterday snuggles up to Labrador-poodle cross Charlie who, according to scientists, is a member of the more intelligent species. Picture: CALUM ROBERTSON Source: AdelaideNow

Scientists claim to have evidence pet dogs are smarter than their feline counterparts.

The reason, they say, is that dogs evolved bigger brains because friendly, social mammals need more grey matter than solitary and aloof ones.

The findings, which are bound to divide pet owners around the world, come from an Oxford University study into the brain size of more than 500 species of living and fossilised mammals.

Study co-author Susanne Shultz said the results overturn the long-held belief that brain size has increased across all mammals. "Dogs have always been regarded as the more social animals, while cats like to get on with their own thing alone," Dr Shultz said.

"But it appears that interaction is good for the brain and extends to other species, like ourselves.

"We are even more social than monkeys and apes, and it is this ability to get on with each other that has helped us dominate the planet."

Sociable mammals such as whales, dogs, dolphins and humans tend to have much larger brains relative to their body size. Solitary species such as tigers, domestic cats and rhinos have smaller ones, the scientists found.

Kazzira Paxtyn, 19, of Highbury, said her labradoodle, Charlie, was quite intelligent.

"You talk to him (Charlie) like a normal person and he knows what you mean straight away; he just understands," she said.

"Dogs just have a great attitude and it's no real surprise that they're smarter." Ms Paxtyn said her cat, Simmo, was a bit clueless.

"My cat isn't very smart at all and I find that cats can be quite rude."

The study, published in the journal Proceedings of the National Academy of Sciences, found that the brains of monkeys expanded the most over evolutionary history - followed by other species which tend to live in stable groups, such as horses, dolphins, camels and dogs.