People who think dogs are exceptionally intelligent are barking up the wrong tree, new research shows.
Scientists reviewed evidence that compared the brain power of dogs with other domestic animals, other social hunters and other carnivorans (an order including animals such as dogs, wolves, bears, lions and hyenas).
The researchers, from the University of Exeter and Canterbury Christ Church University, found the cognitive abilities of dogs were at least matched by several species in each of these groups.
The study examined more than 300 papers on the intelligence of dogs and other animals, and found several cases of "over interpretation" in favour of dogs' abilities.
"During our work it seemed to us that many studies in dog cognition research set out to 'prove' how clever dogs are," said Professor Stephen Lea, of the University of Exeter.
"They are often compared to chimpanzees and whenever dogs 'win', this gets added to their reputation as something exceptional.
"Yet in each and every case we found other valid comparison species that do at least as well as dogs do in those tasks."
The review focussed on sensory cognition, physical cognition, spatial cognition, social cognition and self-awareness.
"Taking all three groups (domestic animals, social hunters and carnivorans) into account, dog cognition does not look exceptional," said Dr Britta Osthaus, of Canterbury Christ Church University.
"We are doing dogs no favour by expecting too much of them. Dogs are dogs, and we need to take their needs and true abilities into account when considering how we treat them."
The paper, published in the journal Learning & Behavior, is entitled: "In what sense are dogs special? Canine cognition in comparative context."